Infectious bursal disease(IBD),caused by IBD virus(IBDV),is one of the most devastating and immunosuppressive diseases of the poultry and has been a constraint on the sustainable poultry production around the globe in...Infectious bursal disease(IBD),caused by IBD virus(IBDV),is one of the most devastating and immunosuppressive diseases of the poultry and has been a constraint on the sustainable poultry production around the globe including Pakistan.While the disease is threatening the poulty industry,the nature of predominant strains of IBDV in Pakistan remained l-defined.In this study,an epidemiology survey was conducted in the main chicken-farming regions of Pakistan.The batch of Pakistan IBDVs genes simultaneously covering both VP1 and VP2 were amplified,sequenced,and analyzed.The unique segment-reassortant IBDVs(vv-A/Uniq-B),carrying segmentA from vvIBDV and segment B from one unique ancestor,were identifed as one important type of circulating strains in Pakistan.The data also discovered the characteristic molecular features of Pakistan IBDVs,which will contribute to scientific vaccine selection and effective prevention of the disease.展开更多
Infectious bursal disease virus(IBDV)is responsible for the highly contagious infectious bursal disease of chickens.Further understanding the gene-function is necessary to design the tailored vaccine.The amino acid ...Infectious bursal disease virus(IBDV)is responsible for the highly contagious infectious bursal disease of chickens.Further understanding the gene-function is necessary to design the tailored vaccine.The amino acid residue 279,located on strand P_F of VP2,is one of the three residues that have been reported to be involved in cell-tropism but with some inconsistency.In this study,to further clarify the amino acids involved in the cell tropism of IBDV,a series of mutations about residue 279were introduced into the VP2 of vv IBDV Gx strain.With the reverse genetic system,we found single mutation of D279N,double mutations of D279N/A284T or Q253H/D279N were not enough to adapt IBDV to chicken embryo fibroblast(CEF)cell.To evaluate whether residue 279 could influence the replication and virulence of IBDV,the virus r Gx HT-279 with three mutations(Q253H/D279N/A284T)was rescued and evaluated.Results showed that the mutation of residue 279 in VP2had no efficient effects on both the replication efficiency in vitro and the virulence to SPF chickens of IBDV.In summary,the results demonstrated that residue 279 of VP2 did not contribute efficiently to cell tropism,replication efficiency,and virulence of IBDV at least in some strains.These findings provided further information for understanding the gene function of IBDV.展开更多
To test whether amino acid mutations in the PBC and PHI loops of VP2 are involved in the replication and virulence of infectious bursal disease virus(IBDV), a pair of viruses, namely the moderately virulent IBDV(rG x-...To test whether amino acid mutations in the PBC and PHI loops of VP2 are involved in the replication and virulence of infectious bursal disease virus(IBDV), a pair of viruses, namely the moderately virulent IBDV(rG x-F9VP2) and the attenuated strain(rGt), were used. Residue mutations A222P(P_(BC)) and S330R(PHI), selected by sequence comparison, were introduced individually into r Gx-F9VP2 by using a reverse genetics system. In addition, the reverse mutation of either P222 A or R330 S was introduced into r Gt. The four modified viruses were then rescued and evaluated in vitro(CEF cells) and in vivo(SPF chickens). Results showed that A222 P elevated the replication efficiency of rG x-F9VP2 while P222 A reduced that of rG t in CEF cells. A mutation at residue 330 did not alter IBDV replication. In addition, animal experiments showed that a single mutation at either residue 222 or 330 did not significantly influence the virulence of IBDV. In conclusion, residue 222 in PBC of VP2 is involved in the replication efficiency of IBDV in vitro but does not affect its virulence in vivo, further facilitating our understanding of the gene-function of IBDV.展开更多
Dear Editor,Infectious bursal disease virus (IBDV) causes an economically significant disease of chickens worldwide (Berg,2000). The molecular basis for the virulence of very virulent IBDV (vvIBDV) is not fully unders...Dear Editor,Infectious bursal disease virus (IBDV) causes an economically significant disease of chickens worldwide (Berg,2000). The molecular basis for the virulence of very virulent IBDV (vvIBDV) is not fully understood. Previous studies have shown that genome segment A, especically VP2 protein, plays the most important role in the tropism and pathogenicity of serotype 1 IBDV (Brandt et al., 2001). VP2 is,however, unlikely to be the only factor for the virulence of vvIBDV (Boot et al., 2000). A chrono-phylogenetic study suggested that the worldwide expansion of vvIBDV展开更多
The mechanism of rabies virus (RABV) infection still needs to be further characterized. RABV particle with self-fluorescent is a powerful viral model to visualize the viral infection process in cells. Herein, based on...The mechanism of rabies virus (RABV) infection still needs to be further characterized. RABV particle with self-fluorescent is a powerful viral model to visualize the viral infection process in cells. Herein, based on a reverse genetic system of the Evelyn-Rokitnicki-Abelseth (rERA) strain, we generated a recombinant RABV rERA-N/mCherry strain that stably expresses an additional ERA nucleoprotein that fuses with the red fluorescent protein mCherry (N/mCherry). The rERA-N/mCherry strain retained growth property similar to the parent strain rERA in vitro. The N/mCherry expression showed genetic stability during passage into mouse neuroblastoma (NA) cells and did not change the virulence of the vector. The rERA-N/mCherry strain was then utilized as a visual viral model to study the RABV-cell binding and internalization. We directly observed the red self-fluorescence of rERA-N/mCherry particles binding to the cell surface, and further co-localizing with clathrin in the early stage of infection in NA cells by fluorescence microscopy. Our results showed that the rERA-N/mCherry strain uses clathrin-dependent endocytosis to enter cells, which is consistent with the well-known mechanism of RABV invasion. The recombinant RABV rERA-N/mCherry thus appears to have the potential to be an effective viral model to further explore the fundamental molecular mechanism of rabies neuropathogenesis.展开更多
H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are prote...H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.展开更多
Theileria luwenshuni and Theileria uilenbergi are important tick-borne pathogens and cause substantial losses to the sheep industry in China. The improvement in detection techniques has allowed the identification of m...Theileria luwenshuni and Theileria uilenbergi are important tick-borne pathogens and cause substantial losses to the sheep industry in China. The improvement in detection techniques has allowed the identification of multi-homing parasitism in Theileria parasites. Herein we evaluated the experimental infectivity of T. luwenshuni and T. uilenbergi in Chinese Kunming mice by screening blood samples of experimentally inoculated mice by microscopic examination(ME) and PCR. T. luwenshuni infected Chinese Kunming mice and 20 mice inoculated with this parasite were positive by ME and PCR. In addition, T. uilenbergi infected mice and 20 mice inoculated with this species were positive by ME and PCR. However, the number of red blood cells and the levels of hemoglobin of 40 infected mice had no obvious changes in the course of infection. Our results demonstrated the multi-homing parasitism of T. luwenshuni and T. uilenbergi, which were believed to be parasites of sheep and goats. This study was the first to demonstrate the infection of T. luwenshuni and T. uilenbergi in Kunming mice.展开更多
Growth hormone (GH) is a polypeptide hormone secreted by the pituitary, which promotes animal growth, muscle development, metabolism regulation and other important physiological functions. In this study, a pair of m...Growth hormone (GH) is a polypeptide hormone secreted by the pituitary, which promotes animal growth, muscle development, metabolism regulation and other important physiological functions. In this study, a pair of mGH short hairpin RNA (shRNA) was designed according to mouse ( Mus musculus) GH mRNA sequence; pSingle-tTS-mGH shRNA-RFP, an integrated controllable expression vector of mGH shRNA, was constructed successfully. The recombinant vector was transfected into mouse pituitary tumor cell line AtT-20. After addition of doxycyelin ( DOX), the expression of red fluorescent protein (RFP) was observed un- der a fluorescent microscope. The expression level of mGH in cells was detected by quantitative Realtime PCR (qRT-PCR) and Western blot. After DOX induction, the relative expression level of GH mRNA in cells transfected with GH shRNA was reduced by about 70% compared with that in DOX-free group and other control groups, exhibiting extremely significant differences (P 〈 0.01 ) ; moreover, the relative expression level of GH protein was reduced by about 90% ; the expression level of GH mRNA and GH protein exhibited no significant difference among other groups (P 〉 0.05). In this study, a controllable expression vector of GH shRNA with high gene silencing efficiency was constructed successfully, which could be used to reveal GH autocfine / paracrine interactions and analyze functions of GH gene in growth, development and disease occurrence of animals by regulating GH expression levels.展开更多
Porcine circovirus type 2(PCV2),which serves as a major causative agent of PCV2-associated diseases and causes severe loss to the pig industry worldwide,can dysregulate the immune response and induce immunosuppression...Porcine circovirus type 2(PCV2),which serves as a major causative agent of PCV2-associated diseases and causes severe loss to the pig industry worldwide,can dysregulate the immune response and induce immunosuppression in PCV2-infected pigs.Similar to PCV2(porcine circovirus type 3(PCV3),a newly identified swine circovirus which might be closely associated with porcine dermatitis and nephropathy syndrome,reproductive disorder,and multisystemic inflammatoty responses,also interferes with host immune defense.Interaction between host immune system and PCVs is considered to be a crucial determinant of pathogenicity in pigs.Here,we sought to briefly discuss the current knowledge regarding the interaction of porcine circovirus type 2 and/or 3 with host immune cells and immune responses to better depict the viral immunomodulatory capacity,pathogenic mechanisms,and the future research direction in host immune responses to infection with PCV2 and PCV3.展开更多
An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibil...An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.展开更多
African swine fever(ASF) is a lethal hemorrhagic disease that affects wild and domestic swine. The etiological agent of ASF is African swine fever virus(ASFV). Since the first case was described in Kenya in 1921, the ...African swine fever(ASF) is a lethal hemorrhagic disease that affects wild and domestic swine. The etiological agent of ASF is African swine fever virus(ASFV). Since the first case was described in Kenya in 1921, the disease has spread to many other countries. No commercial vaccines are available to prevent ASF. In this study, we generated a recombinant Newcastle disease virus(r NDV) expressing ASFV protein 72(p72) by reverse genetics and evaluated its humoral and cellular immunogenicity in a mouse model. The recombinant virus, r NDV/p72, replicated well in embryonated chicken eggs and was safe to use in chicks and mice. The p72 gene in r NDV/p72 was stably maintained through ten passages. Mice immunized with r NDV/p72 developed high titers of ASFV p72 specific Ig G antibody, and had higher levels of Ig G1 than IgG2 a. Immunization also elicited T-cell proliferation and secretion of IFN-γ and IL-4. Taken together, these results indicate that r NDV expressing ASFV p72 might be a potential vaccine candidate for preventing ASF.展开更多
Objective To examine the role of Cd-induced reactive oxygen species(ROS) generation in the apoptosis of neuronal cells. Methods Neuronal cells(primary rat cerebral cortical neurons and PC12 cells) were incubated w...Objective To examine the role of Cd-induced reactive oxygen species(ROS) generation in the apoptosis of neuronal cells. Methods Neuronal cells(primary rat cerebral cortical neurons and PC12 cells) were incubated with or without Cd post-pretreatment with rapamycin(Rap) or N-acetyl-L-cysteine(NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3’-kinase/protein kinase B(Akt)/mammalian target of rapamycin(m TOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays. Results Cd-induced activation of Akt/m TOR signaling, including Akt, m TOR, p70 S6 kinase(p70 S6K), and eukaryotic initiation factor 4E binding protein 1(4E-BP1). Rap, an m TOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/m TOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein(Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase(PARP), and nuclear translocation of apoptosis-inducing factor(AIF) and endonuclease G(Endo G). Conclusion Cd-induced ROS generation activates Akt/m TOR and mitochondrial pathways, leading to apoptosis of neuronal cells. Our findings suggest that m TOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.展开更多
Background:Schistosomiasis remains a major public health concern in China and an epidemiological survey has revealed that schistosome-infected bovines and goats are the main transmission sources for the disease.Theref...Background:Schistosomiasis remains a major public health concern in China and an epidemiological survey has revealed that schistosome-infected bovines and goats are the main transmission sources for the disease.Therefore,development of a sensitive technique for the diagnosis of schistosomiasis in domestic animals is necessary.Method:A novel colloidal gold immunochromatography assay(GICA)strip was developed for detecting Schistosoma japonicum in domestic animals.The colloidal gold was conjugated with recombinant streptococcal protein G(rSPG).As the test and control lines,the schistosome soluble egg antigen and rSPG,respectively,were blotted on nitrocellulose membrane.Results:The lowest detectable serum dilution was 1∶640 for schistosome-infected buffaloes.The cross-reaction rate of GICA was 14.29%with Paramphistomum sp.in buffaloes,16.67%with Haemonchus sp.in goats,and 33.33%with Orientobilharzia sp.in goats.These results were slightly lower and similar to those obtained through ELISA.Moreover,the strips for detecting S.japonicum in mice,rabbits,buffaloes,and goats showed high sensitivity(100.00%,100.00%,100.00%,and 100.00%,respectively)and specificity(100.00%,100.00%,94.23%,and 88.64%,respectively).And the sensitivity or specificity of the GICA strips did not present any significant differences after storage for 12 months at room temperature.When compared with ELISA,the GICA strips exhibited similar sensitivity and specificity in the diagnosis of schistosomiasis in mice,rabbits,buffaloes,and goats.Besides,only 5μl of serum are required for the test and the detection can be completed within 5 min.Conclusion:This study is the first to develop a GICA strip using gold-rSPG conjugate for the diagnosing of schistosomiasis in domestic animals,and preliminary results showed that the developed strip may be suitable for large-scale screening of schistosomiasis in endemic areas.展开更多
Salmonella enterica serovar 4,[5],12:i:-(S.4,[5],12:i:-)is a monophasic variant of Salmonella enterica serovar Typhimurium that has emerged as a global serovar causing public health concern.To date,the epidemiology an...Salmonella enterica serovar 4,[5],12:i:-(S.4,[5],12:i:-)is a monophasic variant of Salmonella enterica serovar Typhimurium that has emerged as a global serovar causing public health concern.To date,the epidemiology and genomic characterization of this pathogen in China have not been well described.We investigated the prevalence,antimicrobial resistance(AMR)phenotypes,and population genomics of sequence type 34(ST34)S.4,[5],12:i:-among cases of human salmonellosis in Henan Province,China.A total of 100 ST34 S.4,[5],12:i:-isolates were studied from 2008 to 2017 and found mostly resistant to ampicillin(AMP),streptomycin(STR),sulfonamides(SUL),and tetracycline(TET)(ASSu T).Bayesian phylogenetic analysis demonstrated that isolates identified in China were mostly related to the European lineage and evolved into two major clades with different resistance genes and plasmid profiles.Notably,clade 1 showed a significantly higher rate of mutations in gyr A and plasmid-mediated quinolone resistance genes.The carrying of the resistance-containing region(encoding R-type ASSu T),including bla(conferring resistance to AMP),str AB(STR),sul2(SUL),and tet(B)(TET)inserted into the flj BA operon,was responsible for most of the monophasic variants in clade 2.Inc HI2 plasmids were the dominant multi-drug resistance mobile genetic elements accounting for the transmission of acquired resistance genes in this serovar,and these were more prevalent in clade 1.Our findings highlighted the increasing prevalence of multi-drug resistant S.4,[5],12:i:-in China,along with the differential characteristics of resistance gene acquisition among various lineages.Based on our data,control measures are required to address the spread of this zoonotic pathogen.Further owing to its potential origin in food-producing animals,a"One Health"approach,should be implemented to support surveillance whilst informing interventional strategies.展开更多
Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect human...Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect humans. There is a lack of efficient vaccines against this disease and the occurrence of antibiotic resistance may render drug therapies ineffective. In this study, gene deletion mutant(ΔSEZ) in pathogenicity islands SeseCisland_4 was constructed. The mutant ΔSEZ had a 52-fold decrease in 50% lethal dose(LD_(50)) and had less capacity to adhere epithelial cells. Importantly, immunization of mice with attenuated vaccine ΔSEZ at the dose of 10~2 colony-forming units(CFU) mL^(–1) elicited a significant humoral antibody response, with an antibody titer of 1:12 800. Therefore, 10~2 CFU mL^(–1) might be used as the appropriate immune dose for the attenuated vaccine ΔSEZ, which provided mice with efficient protection against virulent SEZ. In addition, the hyperimmune sera against 10~2 CFU m L–1 attenuated vaccine ΔSEZ could confer significant protection against virulent SEZ infection in the passive immunization experiment and exhibited efficient bactericidal activity in the whole blood assay. Meanwhile, no viable bacteria was detected in blood when mice were immunized with ΔSEZ at the dose of 10~2 CFU mL^(–1) via hypodermic injection. Thereafter, the mutant ΔSEZ at the dose of 10~2 CFU mL^(–1) could confer significant protection in mice and had less negative effects on host, which could be an effective attenuated vaccine candidate for the prevention of SEZ.展开更多
Objective The current study aims to investigate the effect of Hemagglutinating virus of Japan envelope(HVJ-E) on induction of apoptosis and autophagy in human prostate cancer PC3 cells, and the underlying mechanisms...Objective The current study aims to investigate the effect of Hemagglutinating virus of Japan envelope(HVJ-E) on induction of apoptosis and autophagy in human prostate cancer PC3 cells, and the underlying mechanisms. Methods PC3 cells were treated with HVJ-E at various multiplicity of infection(MOI), and the generated reactive oxygen species(ROS), cell viability, apoptosis, and autophagy were detected, respectively. Next, the role of ROS played in the regulation of HVJ-E-induced apoptosis and autuphagy in PC3 cells were analysed. In the end, the relationship between HVJ-E-induced apoptosis and autuophagy was investigated by using rapamycin and chloroquine. Results Flow cytometry assay revealed that HVJ-E treatment induced dose-dependent apoptosis and that the JNK and p38 MAPK signaling pathways were involved in HVJ-E-induced apoptosis in PC3 cells. In addition, HVJ-E was able to induce autophagy in PC3 cells via the class III PI3 K/beclin-1 pathway. The data also implyed that HVJ-E-triggered autophagy and apoptosis were ROS dependent. When ROS was blocked with N-acetylcysteine(NAC), HVJ-E-induced LC3-II conversion and apoptosis were reversed. Interestingly, HVJ-E-induced apoptosis was significantly increased by an inducer of autophagy, rapamycin pretreatment, both in vitro and in vivo. Conclusion HVJ-E exerts anticancer effects via autophagic cell death in prostate cancer cells.展开更多
CD4^(+)T cells are essential for sustaining CD8^(+)T cell responses during a chronic infection.The adoptive transfer of virus-specific CD4^(+)T cells has been shown to efficiently rescue exhausted CD8^(+)T cells.Howev...CD4^(+)T cells are essential for sustaining CD8^(+)T cell responses during a chronic infection.The adoptive transfer of virus-specific CD4^(+)T cells has been shown to efficiently rescue exhausted CD8^(+)T cells.However,the question of whether endogenous virus-specific CD4^(+)T cell responses can be enhanced by certain vaccination strategies and subsequently reinvigorate exhausted CD8^(+)T cells remains unexplored.In this study,we developed a CD4^(+)T cell epitope-based heterologous prime-boost immunization strategy and examined the efficacy of this strategy using a mouse model of chronic lymphocytic choriomeningitis virus(LCMV)infection.We primed chronically LCMV-infected mice with a Listeria monocytogenes vector that expressed the LCMV glycoprotein-specific I-Ab-restricted CD4^(+)T cell epitope GP61–80(LM-GP61)and subsequently boosted the primed mice with an influenza virus A(PR8 strain)vector that expressed the same CD4^(+)T cell epitope(IAV-GP61).This heterologous prime-boost vaccination strategy elicited strong anti-viral CD4^(+)T cell responses,which further improved both the quantity and quality of the virusspecific CD8^(+)T cells and led to better control of the viral loads.The combination of this strategy and the blockade of the programmed cell death-1(PD-1)inhibitory pathway further enhanced the anti-viral CD8^(+)T cell responses and viral clearance.Thus,a heterologous prime-boost immunization that selectively induces virus-specific CD4^(+)T cell responses in conjunction with blockade of the inhibitory pathway may represent a promising therapeutic approach to treating patients with chronic viral infections.展开更多
Streptococcus suis is one of the major pathogens of swine streptococcosis. Among them, the strongest virulence and highest rate of clinical isolation serotype is S. suis serotype 2(SS2). Moreover, SS2 is also an imp...Streptococcus suis is one of the major pathogens of swine streptococcosis. Among them, the strongest virulence and highest rate of clinical isolation serotype is S. suis serotype 2(SS2). Moreover, SS2 is also an important zoonosis pathogen, which caused severe public health issues in China. It has been reported that SS2 has several virulence factors, including muramidase released protein, extracellular factors, capsule, fibronectin-binding protein, enolase, hemolysin, small RNA, biofilm, two-component regulatory systems, STK/STP, etc., whose functions involved in adhesion, anti-phagocytosis, inflammatory pathway activation, invasion, etc. Actually, SS2 has developed a variety of ways to escape from host immune system during evolution. In particularly, capsule could resist phagocytosis through inhibiting sphingosine dependent immune cell recognition, which plays an important role in escaping host inflammation response; moreover, superoxide dismutase encoding by sod A enables SS2 escaping reactive oxygen species(ROS) in host immune cells; besides, binding complement factor h with Fhb could suppress the activation of complement alternative pathway and bactericidal effect. And SS2 could also hinder the formation of neutrophil extracellular traps(NETs) to avoid trapping by swine neutrophils, while host immune globulin could be degraded by Ig A1 hydrolase and Ig M protease. In addition, SS2 could escape host immune defense with the help of multiple transcriptional factors and micro-RNA. So far, the pathogenesis of meningitis, arthritis caused by SS2 infection, is still unclear, and the virulence regulatory mechanism of phosphorylation, micro-RNA need to be further clarified. Importantly, the study of interaction mechanism of pathogen and host contribute to further demonstration the pathogenesis of SS2.展开更多
Fat is an indispensable nutrient and basic metabolite for sustaining life,and milk is particularly rich in fatty acids,including a variety of saturated and unsaturated fatty acids.MicroRNA(miRNA)and mRNA play an impor...Fat is an indispensable nutrient and basic metabolite for sustaining life,and milk is particularly rich in fatty acids,including a variety of saturated and unsaturated fatty acids.MicroRNA(miRNA)and mRNA play an important role in the regulation of milk fat metabolism in mammary gland tissue.It has been shown that lipid metabolism has a complex transcriptional regulation,but the mechanism by which milk fat synthesis is regulated through miRNA–mRNA interactions is poorly understood.In this study,we performed transcriptome sequencing with bovine mammary gland tissue in the late lactation(270 and 315 days after parturition)to identify the key gene that regulating milk fat metabolism.A total of 1207 differentially coexpressed genes were selected,828 upregulated genes and 379 downregulated genes were identified.The transforming growth factor alpha(TGFA)gene was selected as the target gene,and luciferase reporter assay,Western blotting and q RT-PCR were used for further study.The results demonstrated that miR-140 was an upstream regulator of TGFA,and miR-140 could inhibit(P<0.01)unsaturated fatty acid and triglyceride(TAGs)production in bovine mammary epithelial cells(BMECs).In contrast,TGFA promoted(P<0.01)unsaturated fatty acid and TAG production.Rescue experiments further indicated the mi R-140/TGFA regulatory mechanism.Taken together,these results suggest that the mi R-140/TGFA pathway can inhibit(P<0.01)milk fat metabolism and improve milk quality by genetic means.展开更多
Objective Inactivated Sendai virus particle [hemagglutinating virus of Japan envelope (HVJ-E)] has a potential oncolytic effect due to its ability to induce apoptosis in tumor cells. However, the molecular mechanism...Objective Inactivated Sendai virus particle [hemagglutinating virus of Japan envelope (HVJ-E)] has a potential oncolytic effect due to its ability to induce apoptosis in tumor cells. However, the molecular mechanism of apoptosis induction in cancer cells mediated by HVJ-E has not been fully elucidated. This paper aims to investigate the underlying mechanism of apoptosis induction by HVJ-E in prostate cancer cells (PC3). Methods PC3 cells were treated with HVJ-E at various MOI, and then interferon-β(IFN-β) production, and the cell viability and apoptosis were detected by ELISA, MTl--based assay and flow cytometry, respectively. Next, the roles of Jak-Stat, MAPK and Akt pathways played in HVJ-E-induced apoptosis in PC3 cells were analyzed by immunoblot assay. To further evaluate the cytotoxic effect of HVJ-E on PC3 cells, HVJ-E was intratumorally injected into prostate cancers on BALB/c-nude mice, and the tumor volume was monitored for 36 days. Results HVJ-E induced iFN-β production and activated Jak-Stat signaling pathway, which resulted in the activation of caspase-8, caspase-3, and PARP in PC3 prostate cancer cells post HVJ-E treatment. Furthermore, we observed for the first time that p38 and Jnk MAPKs in PC3 cells contributed to HVJ-E-induced apoptosis. In addition, intratumoral HVJ-E treatment displayed a direct inhibitory effect in an in vivo BALB/c nude mouse prostate cancer model. Conclusion Our findings have provided novel insights into the underlying mechanisms by which HVJ-E induces apoptosis in tumor cells.展开更多
基金This work was supported by the National Key Research and Development Program of China(2016YFE0203200,2017YFD0500704)the Heilongjiang Province Foundation for the National Key Research and Development Program of China(GX18B011)+1 种基金the National Natural Science Foundation of China(31430087)the earmarked fund for the China Agriculture Research System(CARS-41-G15).
文摘Infectious bursal disease(IBD),caused by IBD virus(IBDV),is one of the most devastating and immunosuppressive diseases of the poultry and has been a constraint on the sustainable poultry production around the globe including Pakistan.While the disease is threatening the poulty industry,the nature of predominant strains of IBDV in Pakistan remained l-defined.In this study,an epidemiology survey was conducted in the main chicken-farming regions of Pakistan.The batch of Pakistan IBDVs genes simultaneously covering both VP1 and VP2 were amplified,sequenced,and analyzed.The unique segment-reassortant IBDVs(vv-A/Uniq-B),carrying segmentA from vvIBDV and segment B from one unique ancestor,were identifed as one important type of circulating strains in Pakistan.The data also discovered the characteristic molecular features of Pakistan IBDVs,which will contribute to scientific vaccine selection and effective prevention of the disease.
基金supported by a grant from National Natural Science Foundation of China(31430087)the Scientific and Technological Research Project of Harbin,China(2014AB3AN058)+2 种基金the Special Fund for Scientific and Technological Innovative Talents of Harbin,China(2014RFQYJ129)China-France Cai-Yuanpei Program(2011008007)the Modern Agro-industry Technology Research System of China(nycytx-42-G3-01)
文摘Infectious bursal disease virus(IBDV)is responsible for the highly contagious infectious bursal disease of chickens.Further understanding the gene-function is necessary to design the tailored vaccine.The amino acid residue 279,located on strand P_F of VP2,is one of the three residues that have been reported to be involved in cell-tropism but with some inconsistency.In this study,to further clarify the amino acids involved in the cell tropism of IBDV,a series of mutations about residue 279were introduced into the VP2 of vv IBDV Gx strain.With the reverse genetic system,we found single mutation of D279N,double mutations of D279N/A284T or Q253H/D279N were not enough to adapt IBDV to chicken embryo fibroblast(CEF)cell.To evaluate whether residue 279 could influence the replication and virulence of IBDV,the virus r Gx HT-279 with three mutations(Q253H/D279N/A284T)was rescued and evaluated.Results showed that the mutation of residue 279 in VP2had no efficient effects on both the replication efficiency in vitro and the virulence to SPF chickens of IBDV.In summary,the results demonstrated that residue 279 of VP2 did not contribute efficiently to cell tropism,replication efficiency,and virulence of IBDV at least in some strains.These findings provided further information for understanding the gene function of IBDV.
基金supported by the National Natural Science Foundation of China (31430087)the Scientific and Technological Research Project of Harbin (2014AB3AN058)+1 种基金the Special Fund for Scientific and Technological Innovative Talents of Harbin (2014RFQYJ129)the Modern Agro-industry Technology Research System of China (nycytx-42-G3-01)
文摘To test whether amino acid mutations in the PBC and PHI loops of VP2 are involved in the replication and virulence of infectious bursal disease virus(IBDV), a pair of viruses, namely the moderately virulent IBDV(rG x-F9VP2) and the attenuated strain(rGt), were used. Residue mutations A222P(P_(BC)) and S330R(PHI), selected by sequence comparison, were introduced individually into r Gx-F9VP2 by using a reverse genetics system. In addition, the reverse mutation of either P222 A or R330 S was introduced into r Gt. The four modified viruses were then rescued and evaluated in vitro(CEF cells) and in vivo(SPF chickens). Results showed that A222 P elevated the replication efficiency of rG x-F9VP2 while P222 A reduced that of rG t in CEF cells. A mutation at residue 330 did not alter IBDV replication. In addition, animal experiments showed that a single mutation at either residue 222 or 330 did not significantly influence the virulence of IBDV. In conclusion, residue 222 in PBC of VP2 is involved in the replication efficiency of IBDV in vitro but does not affect its virulence in vivo, further facilitating our understanding of the gene-function of IBDV.
基金supported by the National Natural Science Foundation of China (31500129, 31430087)
文摘Dear Editor,Infectious bursal disease virus (IBDV) causes an economically significant disease of chickens worldwide (Berg,2000). The molecular basis for the virulence of very virulent IBDV (vvIBDV) is not fully understood. Previous studies have shown that genome segment A, especically VP2 protein, plays the most important role in the tropism and pathogenicity of serotype 1 IBDV (Brandt et al., 2001). VP2 is,however, unlikely to be the only factor for the virulence of vvIBDV (Boot et al., 2000). A chrono-phylogenetic study suggested that the worldwide expansion of vvIBDV
基金supported by the National Natural Science Fundation of China (31800138)the National Key Research and Development Program of China (2016YFD0500403)
文摘The mechanism of rabies virus (RABV) infection still needs to be further characterized. RABV particle with self-fluorescent is a powerful viral model to visualize the viral infection process in cells. Herein, based on a reverse genetic system of the Evelyn-Rokitnicki-Abelseth (rERA) strain, we generated a recombinant RABV rERA-N/mCherry strain that stably expresses an additional ERA nucleoprotein that fuses with the red fluorescent protein mCherry (N/mCherry). The rERA-N/mCherry strain retained growth property similar to the parent strain rERA in vitro. The N/mCherry expression showed genetic stability during passage into mouse neuroblastoma (NA) cells and did not change the virulence of the vector. The rERA-N/mCherry strain was then utilized as a visual viral model to study the RABV-cell binding and internalization. We directly observed the red self-fluorescence of rERA-N/mCherry particles binding to the cell surface, and further co-localizing with clathrin in the early stage of infection in NA cells by fluorescence microscopy. Our results showed that the rERA-N/mCherry strain uses clathrin-dependent endocytosis to enter cells, which is consistent with the well-known mechanism of RABV invasion. The recombinant RABV rERA-N/mCherry thus appears to have the potential to be an effective viral model to further explore the fundamental molecular mechanism of rabies neuropathogenesis.
基金supported by the earmarked fund for China Agriculture Research System(CARS-40)the Key Research and Development Project of Yangzhou(Modern Agriculture),China(YZ2022052)the‘‘High-end Talent Support Program’’of Yangzhou University,China。
文摘H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.
基金financially supported by the National Key Research and Development Program of China (2017YFD0501200, 2016YFC1202000, 2016YFC1202002)the earmarked fund for China Agriculture Research System (CARS-37)+5 种基金the National Natural Science Foundation of China (31272556, 31402189, 31372432)the Agricultural Science and Technology Innovation Program, China (2014ZL010)the National Basic Research Program of China (2015CB150300)the Special Funds for Agroscientific Research in the Public Research, China (201303035)the Gansu International Collaboration Special Project, China (1504WKCA056)the Jiangsu Co-Innovation Center Programme for Prevention and Control of Important Animal Infectious Diseases and Zoonoses,State Key Laboratory of Veterinary Etiological Biology Project, China
文摘Theileria luwenshuni and Theileria uilenbergi are important tick-borne pathogens and cause substantial losses to the sheep industry in China. The improvement in detection techniques has allowed the identification of multi-homing parasitism in Theileria parasites. Herein we evaluated the experimental infectivity of T. luwenshuni and T. uilenbergi in Chinese Kunming mice by screening blood samples of experimentally inoculated mice by microscopic examination(ME) and PCR. T. luwenshuni infected Chinese Kunming mice and 20 mice inoculated with this parasite were positive by ME and PCR. In addition, T. uilenbergi infected mice and 20 mice inoculated with this species were positive by ME and PCR. However, the number of red blood cells and the levels of hemoglobin of 40 infected mice had no obvious changes in the course of infection. Our results demonstrated the multi-homing parasitism of T. luwenshuni and T. uilenbergi, which were believed to be parasites of sheep and goats. This study was the first to demonstrate the infection of T. luwenshuni and T. uilenbergi in Kunming mice.
基金Supported by National Natural Science Foundation of China(31101683,31272405)Priority Academic Program Development of Jiangsu Higher Education Institutions(2014)Science and Technology Innovation Fund for Students in Yangzhou University(No.x2015719)
文摘Growth hormone (GH) is a polypeptide hormone secreted by the pituitary, which promotes animal growth, muscle development, metabolism regulation and other important physiological functions. In this study, a pair of mGH short hairpin RNA (shRNA) was designed according to mouse ( Mus musculus) GH mRNA sequence; pSingle-tTS-mGH shRNA-RFP, an integrated controllable expression vector of mGH shRNA, was constructed successfully. The recombinant vector was transfected into mouse pituitary tumor cell line AtT-20. After addition of doxycyelin ( DOX), the expression of red fluorescent protein (RFP) was observed un- der a fluorescent microscope. The expression level of mGH in cells was detected by quantitative Realtime PCR (qRT-PCR) and Western blot. After DOX induction, the relative expression level of GH mRNA in cells transfected with GH shRNA was reduced by about 70% compared with that in DOX-free group and other control groups, exhibiting extremely significant differences (P 〈 0.01 ) ; moreover, the relative expression level of GH protein was reduced by about 90% ; the expression level of GH mRNA and GH protein exhibited no significant difference among other groups (P 〉 0.05). In this study, a controllable expression vector of GH shRNA with high gene silencing efficiency was constructed successfully, which could be used to reveal GH autocfine / paracrine interactions and analyze functions of GH gene in growth, development and disease occurrence of animals by regulating GH expression levels.
基金This study was supported by a grant from the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Porcine circovirus type 2(PCV2),which serves as a major causative agent of PCV2-associated diseases and causes severe loss to the pig industry worldwide,can dysregulate the immune response and induce immunosuppression in PCV2-infected pigs.Similar to PCV2(porcine circovirus type 3(PCV3),a newly identified swine circovirus which might be closely associated with porcine dermatitis and nephropathy syndrome,reproductive disorder,and multisystemic inflammatoty responses,also interferes with host immune defense.Interaction between host immune system and PCVs is considered to be a crucial determinant of pathogenicity in pigs.Here,we sought to briefly discuss the current knowledge regarding the interaction of porcine circovirus type 2 and/or 3 with host immune cells and immune responses to better depict the viral immunomodulatory capacity,pathogenic mechanisms,and the future research direction in host immune responses to infection with PCV2 and PCV3.
基金the National Key Research and Development Program of China(2018YFE0192600)the Shanghai Agriculture Applied Technology Development Program,China(T20200104)+1 种基金the Fundamental Research Funds for the Central Universities,China(2020JB05)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202203).
文摘An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.
基金financially supported by the National Supporting Program(2013BAD12B05)Natural Science Foundation of China(NSFC)(no.31101839 and no.31302117)+1 种基金the key program of Gansu Province(no.1013JHTA008)Jiangsu Co-innovation Center program for Prevention and Control of Important Animal Infectious Diseases and Zoonoses
文摘African swine fever(ASF) is a lethal hemorrhagic disease that affects wild and domestic swine. The etiological agent of ASF is African swine fever virus(ASFV). Since the first case was described in Kenya in 1921, the disease has spread to many other countries. No commercial vaccines are available to prevent ASF. In this study, we generated a recombinant Newcastle disease virus(r NDV) expressing ASFV protein 72(p72) by reverse genetics and evaluated its humoral and cellular immunogenicity in a mouse model. The recombinant virus, r NDV/p72, replicated well in embryonated chicken eggs and was safe to use in chicks and mice. The p72 gene in r NDV/p72 was stably maintained through ten passages. Mice immunized with r NDV/p72 developed high titers of ASFV p72 specific Ig G antibody, and had higher levels of Ig G1 than IgG2 a. Immunization also elicited T-cell proliferation and secretion of IFN-γ and IL-4. Taken together, these results indicate that r NDV expressing ASFV p72 might be a potential vaccine candidate for preventing ASF.
基金supported by the National Natural Science Foundation of China(No.31101866 and 31302058)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China Postdoctoral Science Foundation funded project(2015M581874)Jiangsu Planned Projects for Postdoctoral Research Funds(1501072A)
文摘Objective To examine the role of Cd-induced reactive oxygen species(ROS) generation in the apoptosis of neuronal cells. Methods Neuronal cells(primary rat cerebral cortical neurons and PC12 cells) were incubated with or without Cd post-pretreatment with rapamycin(Rap) or N-acetyl-L-cysteine(NAC). Cell viability was determined by MTT assay, apoptosis was examined using flow cytometry and fluorescence microscopy, and the activation of phosphoinositide 3’-kinase/protein kinase B(Akt)/mammalian target of rapamycin(m TOR) and mitochondrial apoptotic pathways were measured by western blotting or immunofluorescence assays. Results Cd-induced activation of Akt/m TOR signaling, including Akt, m TOR, p70 S6 kinase(p70 S6K), and eukaryotic initiation factor 4E binding protein 1(4E-BP1). Rap, an m TOR inhibitor and NAC, a ROS scavenger, blocked Cd-induced activation of Akt/m TOR signaling and apoptosis of neuronal cells. Furthermore, NAC blocked the decrease of B-cell lymphoma 2/Bcl-2 associated X protein(Bcl-2/Bax) ratio, release of cytochrome c, cleavage of caspase-3 and poly(ADP-ribose) polymerase(PARP), and nuclear translocation of apoptosis-inducing factor(AIF) and endonuclease G(Endo G). Conclusion Cd-induced ROS generation activates Akt/m TOR and mitochondrial pathways, leading to apoptosis of neuronal cells. Our findings suggest that m TOR inhibitors or antioxidants have potential for preventing Cd-induced neurodegenerative diseases.
基金This study was financially supported by the Basic Foundation for Scientific Research of State-level Public Welfare Institutes of China(Grant no.2014JB01).
文摘Background:Schistosomiasis remains a major public health concern in China and an epidemiological survey has revealed that schistosome-infected bovines and goats are the main transmission sources for the disease.Therefore,development of a sensitive technique for the diagnosis of schistosomiasis in domestic animals is necessary.Method:A novel colloidal gold immunochromatography assay(GICA)strip was developed for detecting Schistosoma japonicum in domestic animals.The colloidal gold was conjugated with recombinant streptococcal protein G(rSPG).As the test and control lines,the schistosome soluble egg antigen and rSPG,respectively,were blotted on nitrocellulose membrane.Results:The lowest detectable serum dilution was 1∶640 for schistosome-infected buffaloes.The cross-reaction rate of GICA was 14.29%with Paramphistomum sp.in buffaloes,16.67%with Haemonchus sp.in goats,and 33.33%with Orientobilharzia sp.in goats.These results were slightly lower and similar to those obtained through ELISA.Moreover,the strips for detecting S.japonicum in mice,rabbits,buffaloes,and goats showed high sensitivity(100.00%,100.00%,100.00%,and 100.00%,respectively)and specificity(100.00%,100.00%,94.23%,and 88.64%,respectively).And the sensitivity or specificity of the GICA strips did not present any significant differences after storage for 12 months at room temperature.When compared with ELISA,the GICA strips exhibited similar sensitivity and specificity in the diagnosis of schistosomiasis in mice,rabbits,buffaloes,and goats.Besides,only 5μl of serum are required for the test and the detection can be completed within 5 min.Conclusion:This study is the first to develop a GICA strip using gold-rSPG conjugate for the diagnosing of schistosomiasis in domestic animals,and preliminary results showed that the developed strip may be suitable for large-scale screening of schistosomiasis in endemic areas.
基金supported by grants from the National Natural Science Foundation of China(31871899 and 31930110)Henan Medical Science and Technology Research Plan(LHGJ20200128)。
文摘Salmonella enterica serovar 4,[5],12:i:-(S.4,[5],12:i:-)is a monophasic variant of Salmonella enterica serovar Typhimurium that has emerged as a global serovar causing public health concern.To date,the epidemiology and genomic characterization of this pathogen in China have not been well described.We investigated the prevalence,antimicrobial resistance(AMR)phenotypes,and population genomics of sequence type 34(ST34)S.4,[5],12:i:-among cases of human salmonellosis in Henan Province,China.A total of 100 ST34 S.4,[5],12:i:-isolates were studied from 2008 to 2017 and found mostly resistant to ampicillin(AMP),streptomycin(STR),sulfonamides(SUL),and tetracycline(TET)(ASSu T).Bayesian phylogenetic analysis demonstrated that isolates identified in China were mostly related to the European lineage and evolved into two major clades with different resistance genes and plasmid profiles.Notably,clade 1 showed a significantly higher rate of mutations in gyr A and plasmid-mediated quinolone resistance genes.The carrying of the resistance-containing region(encoding R-type ASSu T),including bla(conferring resistance to AMP),str AB(STR),sul2(SUL),and tet(B)(TET)inserted into the flj BA operon,was responsible for most of the monophasic variants in clade 2.Inc HI2 plasmids were the dominant multi-drug resistance mobile genetic elements accounting for the transmission of acquired resistance genes in this serovar,and these were more prevalent in clade 1.Our findings highlighted the increasing prevalence of multi-drug resistant S.4,[5],12:i:-in China,along with the differential characteristics of resistance gene acquisition among various lineages.Based on our data,control measures are required to address the spread of this zoonotic pathogen.Further owing to its potential origin in food-producing animals,a"One Health"approach,should be implemented to support surveillance whilst informing interventional strategies.
基金was supported by the National Key R&D Program of China(2017YFD0500203)the National Natural Science Foundation of China(31672574)+3 种基金the Special Fund for Agro-scientific Research in the Public Interest,China(201403054)the Primary Research&Development Plan of Jiangsu Province,China(BE2017341)the Jiangsu Agricultural Science and Technology Innovation Fund [CX(16)1028]the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)
文摘Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect humans. There is a lack of efficient vaccines against this disease and the occurrence of antibiotic resistance may render drug therapies ineffective. In this study, gene deletion mutant(ΔSEZ) in pathogenicity islands SeseCisland_4 was constructed. The mutant ΔSEZ had a 52-fold decrease in 50% lethal dose(LD_(50)) and had less capacity to adhere epithelial cells. Importantly, immunization of mice with attenuated vaccine ΔSEZ at the dose of 10~2 colony-forming units(CFU) mL^(–1) elicited a significant humoral antibody response, with an antibody titer of 1:12 800. Therefore, 10~2 CFU mL^(–1) might be used as the appropriate immune dose for the attenuated vaccine ΔSEZ, which provided mice with efficient protection against virulent SEZ. In addition, the hyperimmune sera against 10~2 CFU m L–1 attenuated vaccine ΔSEZ could confer significant protection against virulent SEZ infection in the passive immunization experiment and exhibited efficient bactericidal activity in the whole blood assay. Meanwhile, no viable bacteria was detected in blood when mice were immunized with ΔSEZ at the dose of 10~2 CFU mL^(–1) via hypodermic injection. Thereafter, the mutant ΔSEZ at the dose of 10~2 CFU mL^(–1) could confer significant protection in mice and had less negative effects on host, which could be an effective attenuated vaccine candidate for the prevention of SEZ.
基金supported by the National Key Research and Development Program of China[2017YFD0502303]National N atural Science Foundation of China[No.31302042]High-end Talent Support Program of Yangzhou University and the Young and Middle-aged Academic Leaders Plan of Yangzhou University and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Objective The current study aims to investigate the effect of Hemagglutinating virus of Japan envelope(HVJ-E) on induction of apoptosis and autophagy in human prostate cancer PC3 cells, and the underlying mechanisms. Methods PC3 cells were treated with HVJ-E at various multiplicity of infection(MOI), and the generated reactive oxygen species(ROS), cell viability, apoptosis, and autophagy were detected, respectively. Next, the role of ROS played in the regulation of HVJ-E-induced apoptosis and autuphagy in PC3 cells were analysed. In the end, the relationship between HVJ-E-induced apoptosis and autuophagy was investigated by using rapamycin and chloroquine. Results Flow cytometry assay revealed that HVJ-E treatment induced dose-dependent apoptosis and that the JNK and p38 MAPK signaling pathways were involved in HVJ-E-induced apoptosis in PC3 cells. In addition, HVJ-E was able to induce autophagy in PC3 cells via the class III PI3 K/beclin-1 pathway. The data also implyed that HVJ-E-triggered autophagy and apoptosis were ROS dependent. When ROS was blocked with N-acetylcysteine(NAC), HVJ-E-induced LC3-II conversion and apoptosis were reversed. Interestingly, HVJ-E-induced apoptosis was significantly increased by an inducer of autophagy, rapamycin pretreatment, both in vitro and in vivo. Conclusion HVJ-E exerts anticancer effects via autophagic cell death in prostate cancer cells.
基金The work was supported by National Basic Research Program of China(973 program,2013CB531500,to LY)the National Natural Science Foundation of China(81471624 to LY).
文摘CD4^(+)T cells are essential for sustaining CD8^(+)T cell responses during a chronic infection.The adoptive transfer of virus-specific CD4^(+)T cells has been shown to efficiently rescue exhausted CD8^(+)T cells.However,the question of whether endogenous virus-specific CD4^(+)T cell responses can be enhanced by certain vaccination strategies and subsequently reinvigorate exhausted CD8^(+)T cells remains unexplored.In this study,we developed a CD4^(+)T cell epitope-based heterologous prime-boost immunization strategy and examined the efficacy of this strategy using a mouse model of chronic lymphocytic choriomeningitis virus(LCMV)infection.We primed chronically LCMV-infected mice with a Listeria monocytogenes vector that expressed the LCMV glycoprotein-specific I-Ab-restricted CD4^(+)T cell epitope GP61–80(LM-GP61)and subsequently boosted the primed mice with an influenza virus A(PR8 strain)vector that expressed the same CD4^(+)T cell epitope(IAV-GP61).This heterologous prime-boost vaccination strategy elicited strong anti-viral CD4^(+)T cell responses,which further improved both the quantity and quality of the virusspecific CD8^(+)T cells and led to better control of the viral loads.The combination of this strategy and the blockade of the programmed cell death-1(PD-1)inhibitory pathway further enhanced the anti-viral CD8^(+)T cell responses and viral clearance.Thus,a heterologous prime-boost immunization that selectively induces virus-specific CD4^(+)T cell responses in conjunction with blockade of the inhibitory pathway may represent a promising therapeutic approach to treating patients with chronic viral infections.
基金supported by the National Key R&D Program of China (2017YFD0500203)the National Transgenic Major Program of China (2014ZX0800946B)+3 种基金the National NaturalScience Foundation of China (31672574)the Special Fund for Agro-scientific Research in the Public Interest, China (201403054)the Jiangsu Agricultural Science and Technology Innovation Fund, China ([CX (16) 1028])the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘Streptococcus suis is one of the major pathogens of swine streptococcosis. Among them, the strongest virulence and highest rate of clinical isolation serotype is S. suis serotype 2(SS2). Moreover, SS2 is also an important zoonosis pathogen, which caused severe public health issues in China. It has been reported that SS2 has several virulence factors, including muramidase released protein, extracellular factors, capsule, fibronectin-binding protein, enolase, hemolysin, small RNA, biofilm, two-component regulatory systems, STK/STP, etc., whose functions involved in adhesion, anti-phagocytosis, inflammatory pathway activation, invasion, etc. Actually, SS2 has developed a variety of ways to escape from host immune system during evolution. In particularly, capsule could resist phagocytosis through inhibiting sphingosine dependent immune cell recognition, which plays an important role in escaping host inflammation response; moreover, superoxide dismutase encoding by sod A enables SS2 escaping reactive oxygen species(ROS) in host immune cells; besides, binding complement factor h with Fhb could suppress the activation of complement alternative pathway and bactericidal effect. And SS2 could also hinder the formation of neutrophil extracellular traps(NETs) to avoid trapping by swine neutrophils, while host immune globulin could be degraded by Ig A1 hydrolase and Ig M protease. In addition, SS2 could escape host immune defense with the help of multiple transcriptional factors and micro-RNA. So far, the pathogenesis of meningitis, arthritis caused by SS2 infection, is still unclear, and the virulence regulatory mechanism of phosphorylation, micro-RNA need to be further clarified. Importantly, the study of interaction mechanism of pathogen and host contribute to further demonstration the pathogenesis of SS2.
基金supported by the National Natural Science Foundation of China (31802035, 31872324 and 31601915)
文摘Fat is an indispensable nutrient and basic metabolite for sustaining life,and milk is particularly rich in fatty acids,including a variety of saturated and unsaturated fatty acids.MicroRNA(miRNA)and mRNA play an important role in the regulation of milk fat metabolism in mammary gland tissue.It has been shown that lipid metabolism has a complex transcriptional regulation,but the mechanism by which milk fat synthesis is regulated through miRNA–mRNA interactions is poorly understood.In this study,we performed transcriptome sequencing with bovine mammary gland tissue in the late lactation(270 and 315 days after parturition)to identify the key gene that regulating milk fat metabolism.A total of 1207 differentially coexpressed genes were selected,828 upregulated genes and 379 downregulated genes were identified.The transforming growth factor alpha(TGFA)gene was selected as the target gene,and luciferase reporter assay,Western blotting and q RT-PCR were used for further study.The results demonstrated that miR-140 was an upstream regulator of TGFA,and miR-140 could inhibit(P<0.01)unsaturated fatty acid and triglyceride(TAGs)production in bovine mammary epithelial cells(BMECs).In contrast,TGFA promoted(P<0.01)unsaturated fatty acid and TAG production.Rescue experiments further indicated the mi R-140/TGFA regulatory mechanism.Taken together,these results suggest that the mi R-140/TGFA pathway can inhibit(P<0.01)milk fat metabolism and improve milk quality by genetic means.
基金supported by Natural Science Foundation of Jiangsu Province(BK20130445)National Natural Science foundation of China(No.31302042)
文摘Objective Inactivated Sendai virus particle [hemagglutinating virus of Japan envelope (HVJ-E)] has a potential oncolytic effect due to its ability to induce apoptosis in tumor cells. However, the molecular mechanism of apoptosis induction in cancer cells mediated by HVJ-E has not been fully elucidated. This paper aims to investigate the underlying mechanism of apoptosis induction by HVJ-E in prostate cancer cells (PC3). Methods PC3 cells were treated with HVJ-E at various MOI, and then interferon-β(IFN-β) production, and the cell viability and apoptosis were detected by ELISA, MTl--based assay and flow cytometry, respectively. Next, the roles of Jak-Stat, MAPK and Akt pathways played in HVJ-E-induced apoptosis in PC3 cells were analyzed by immunoblot assay. To further evaluate the cytotoxic effect of HVJ-E on PC3 cells, HVJ-E was intratumorally injected into prostate cancers on BALB/c-nude mice, and the tumor volume was monitored for 36 days. Results HVJ-E induced iFN-β production and activated Jak-Stat signaling pathway, which resulted in the activation of caspase-8, caspase-3, and PARP in PC3 prostate cancer cells post HVJ-E treatment. Furthermore, we observed for the first time that p38 and Jnk MAPKs in PC3 cells contributed to HVJ-E-induced apoptosis. In addition, intratumoral HVJ-E treatment displayed a direct inhibitory effect in an in vivo BALB/c nude mouse prostate cancer model. Conclusion Our findings have provided novel insights into the underlying mechanisms by which HVJ-E induces apoptosis in tumor cells.