Immune response to inactivated bacterial vector carrying the recombinant K39 antigen of Leishmania infantum in mice

Objective:To evaluate the immunological response elicited by an inactivated bacterial vector carrying the K39 antigen of Leishmania infantum,and a purified antigen.Methods:Mice were subjected to the following treatments:(1)Purified recombinant K39(rK39)protein at a 20μg dose with complete Freund’s adjuvant;(2)Inactivated Escherichia coli(BL21 DE3)carrying the K39 protein at an equivalent total protein content of 200μg;(3)Inactivated bacteria lacking the K39 protein;(4)Non-immunized control animals.Serological monitoring was performed.All groups were challenged by intraperitoneal injection of 10^(7) Leishmania infantum promastigotes.After euthanasia,the liver and spleen were collected to analyze the levels of TNF,IFN-γ,IL-12,IL-4,and IL-10.Results:Mice immunized with purified rK39 or the inactivated bacterial vector carrying the K39 antigen of Leishmania infantum showed a long-lasting immune response with high levels of polyclonal antibodies specifically recognizing the recombinant proteins.The IgG1 subclass was the predominant immunoglobulin;however,the induction of IgG2a and the profile of cytokines produced were indicative of the induction of a mixed-type response.Conclusions:The inactivated bacterial vector carrying the K39 antigen,as well as the purified antigen can induce a long-lasting immune response in immunized mice,predominantly favouring a Th2 profile response.

Immune responses of six-transmembrane epithelial antigen of the prostate 4 functions as a novel biomarker in gastric cancer

BACKGROUND Immune cells play an important role in regulating the behavior of tumor cells.According to emerging evidence,six-transmembrane epithelial antigen of the prostate 4(STEAP4)performs a crucial part in tumor microenvironmental immune response and tumorigenesis,and serves as the potential target for cellular and antibody immunotherapy.However,the immunotherapeutic role of STEAP4 in gastric cancer(GC)remains unclear.AIM To investigate the expression of STEAP4 in GC and its relationship with immune infiltrating cells,and explore the potential value of STEAP4 as an immune prognostic indicator in GC.METHODS The expression level of STEAP4 was characterized by immunohistochemistry in tumors and adjacent non-cancerous samples in 96 GC patients.Tumor Immune Estimation Resource was used to study the correlation between STEAP4 and tumor immune infiltration level and immune infiltration gene signature.R package was used to analyze the relationship between STEAP4 expression and immune and stromal scores in GC(GSE62254)by the ESTIMATE algorithm,and Kaplan-Meier Plotter and Gene Expression Profiling Interactive Analysis were applied to analyze the effect of STEAP4 on clinical prognosis.RESULTS Immunohistochemistry analysis showed that STEAP4 expression was higher in GC tissues than in adjacent tissues,and STEAP4 expression was positively correlated with the clinical stage of GC.In GC,the expression of STEAP4 was positively correlated with the infiltration levels of B cells,CD4+T cells,macrophages,neutrophils,and dendritic cells.The expression level of STEAP4 was strongly correlated with most of the immune markers.In addition,STEAP4 expression was inversely correlated with tumor purity,but correlated with stromal score(r=0.43,P<0.001),immune score(r=0.29,P<0.001)and estimate score(r=0.39,P<0.001).Moreover,stromal,immune,and estimate scores were higher in the STEAP4 high expression group,whereas tumor purity was higher in the STEAP4 Low expression group.The relationship between STEAP4 expression and prognosis of patients with GC was further investigated,and the results showed that high STEAP4 expression was associated with poor overall survival and disease-free survival.In addition,Kaplan-Meier Plotter showed that high expression of STEAP4 was significantly correlated with poor survival of patients with GC.CONCLUSION The current findings suggest an oncogenic role for STEAP4 in GC,with significantly high levels being associated with poor prognosis.Investigation of the GC tumor microenvironment suggests the potential function of STEAP4 is connected with the infiltration of diverse immune cells,which may contribute to the regulation of the tumor microenvironment.In conclusion,STEAP4 may serve as a potential therapeutic target for GC to improve the immune infiltration,as well as serve as a prognostic biomarker for judging the prognosis and immune infiltration status of GC.

Inhibition of host immune response in colorectal cancer:Human leukocyte antigen-G and beyond

Colorectal cancer (CRC) is one of the most diffuse cancers worldwide and is still a clinical burden. Increasing evidences associate CRC clinical outcome to immune contexture represented by adaptive immune cells. Their type, density and location are summarized in the Immune Score that has been shown to improve prognostic prediction of CRC patients. The non-classical MHC class&#x02005;I&#x02005;human leukocyte antigen-G (HLA-G), is a crucial tumor-driven immune escape molecule involved in immune tolerance. HLA-G and soluble counterparts are able to exert inhibitory functions by direct interactions with inhibitory receptors present on both innate cells such as natural killer cells, and adaptive immune cells as cytotoxic T and B lymphocytes. HLA-G may play a prominent role in CRC strategies to avoid host immunosurveillance. This review highlights the current knowledge on HLA-G contribution in CRC, in related inflammatory diseases and in other type of cancers and disorders. HLA-G genetic setting (specific haplotypes, genotypes and alleles frequencies) and association with circulating/soluble profiles was highlighted. HLA G prognostic and predictive value in CRC was investigated in order to define a novel prognostic immune biomarker in CRC.

Expression of p30, the major surface antigen of Toxoplasma gondii, in baculovirus-insect cell system and the evaluation of immune response induced by p30

Objective: To produce the major surface antigen (p30) of Toxoplasma gondii from the Baculovirus Expression System. Methods: The p30 coding sequence was cloned into a transfer vector, then the recombinant baculovirus containing p30 gene was cloned and purified by the co-transfection and plaque assay. The expression and immunoactivity of the recombinant p30 were analyzed by SDS-PAGE and Western blot. The immune responses in mice for being immunized with recombinant p30 were tested. Results: About 750μg of purified (95% purity) p30 was obtained from a culture of 108 in- sect Sf21 cells. Mice in injected with the recombinant protein produced specific humoral and cellular immune responses. Immunization with p30 also prolonged the period of mice survival infected by Toxoplasma gondii. Conclusion: It is indicated that the recombinant p30 from baculovirus expression system can stimulate mice to produce effective protection from Toxo- plasma gondii infection.

Effects of Rosa roxburghii&edible fungus fermentation broth on immune response and gut microbiota in immunosuppressed mice

With the rise of probiotics fermentation in food industry,fermented foods have attracted worldwide attention.In this study,protective effects of Rosa roxburghii&edible fungus fermentation broth(REFB)on immune function and gut health in Cyclophosphamide induced immunosuppressed mice were investigated.Results showed that REFB could improve the immune organ index,and promote the proliferation and differentiation of splenic T lymphocytes.In addition,it attenuated intestinal mucosal damage and improved intestinal cellular immunity.REFB administration also up-regulated the expression of IL-4,INF-γ,TNF-α,T-bet and GATA-3 mRNA in small intestine.Furthermore,administration of REFB modulated gut microbiota composition and increased the relative abundance of beneficial genus,such as Bacteroides.It also increased the production of fecal short-chain fatty acids.These indicate that REFB has the potential to improve immunity,alleviate intestinal injury and regulate gut microbiota in immunosuppressed mice.

Effect of dietary supplement of inactivated Lactobacillus plantarum Ep-M 17 on growth performance,immune response,disease resistance,and intestinal microbiota in Penaeus vannamei

Our previous study found that feeding with Lactobacillus plantarum Ep-M17 could effectively affect the growth performance,immune response,and gut microbiota of Penaeus vannamei.However,high temperature and pressure during feed pelletizing is the main problem that can lead to a decrease in the activity of probiotics or cause their inactivation.Further investigation needs to investigate whether inactivated Ep-M17 can exert similar effects as live Ep-M17.Therefore,we evaluated the effects of inactivated L.plantarum Ep-M17 on growth performance,immune response,disease resistance,and gut microbiota in P.vannamei.Results show that adding inactivated Ep-M17 to the feed also promoted body weight gain and increased relative immune protection in shrimp.Also,histological examination revealed that the administration of inactivated Ep-M17 led to improvements in the density and distribution of microvilli in the intestines and enhancements in the abundance of B and R cells in the hepatopancreas.Additionally,the inactivated Ep-M17 supplementation resulted in increased activity levels of nutrient immune-related enzymes in both the shrimp hepatopancreas and intestines.Moreover,it stimulated the expression of Lvlec,PEN-3a,Crustin,LGBP,Lysozyme,and proPo genes in both the hepatopancreas and intestines.Furthermore,the inactivated Ep-M17 also increased bacterial diversity in the gut of shrimp and promoted the abundance of specific flora,facilitating the host organism’s metabolism and immunity to improve the disease resistance of shrimp.Therefore,supplementation of inactivated L.plantarum Ep-M17 in shrimp diets can exert similar effects as live L.plantarum Ep-M17 effectively improving growth performance,gut microbiota,immune response,and disease resistance in P.vannamei.

NIR-triggered on-site NO/ROS/RNS nanoreactor:Cascade-amplified photodynamic/photothermal therapy with local and systemic immune responses activation

Photothermal and photodynamic therapies(PTT/PDT)hold promise for localized tumor treatment,yet their full potential is hampered by limitations such as the hypoxic tumor microenvironment and inadequate systemic immune activation.Addressing these challenges,we present a novel near-infrared(NIR)-triggered RNS nanoreactor(PBNO-Ce6)to amplify the photodynamic and photothermal therapy efficacy against triple-negative breast cancer(TNBC).The designed PBNOCe6 combines sodium nitroprusside-doped Prussian Blue nanoparticles with Chlorin e6 to enable on-site RNS production through NIR-induced concurrent NO release and ROS generation.This not only enhances tumor cell eradication but also potentiates local and systemic antitumor immune responses,protecting mice from tumor rechallenge.Our in vivo evaluations revealed that treatment with PBNO-Ce6 leads to a remarkable 2.7-fold increase in cytotoxic T lymphocytes and a 62%decrease in regulatory T cells in comparison to the control PB-Ce6(Prussian Blue nanoparticles loaded with Chlorin e6),marking a substantial improvement over traditional PTT/PDT.As such,the PBNO-Ce6 nanoreactor represents a transformative approach for improving outcomes in TNBC and potentially other malignancies affected by similar barriers.

Acupoint catgut-embedding therapy ameliorates DNCB-induced atopic dermatitis in BALB/c mice by regulating Th2 type immune response and reducing infiltration of CD4^(+)and CD8^(+)cells

Background:This study aimed to assess how acupoint catgut-embedding therapy influences Th2-type immune response and the infiltration of CD4^(+)and CD8^(+)cells in DNCB-induced atopic dermatitis in BALB/c mice.It also conducted an initial examination of the underlying molecular mechanisms.Methods:Seventy-two mice were randomly divided into four groups:normal control,DNCB-induced atopic dermatitis model(AD),AD with acupoint catgut-embedding treatment(ADA),and AD with sham-acupoint catgut-embedding treatment.After DNCB challenge to induce AD,the ADA group received acupoint catgut-embedding therapy treatment at Zusanli(ST 36)and Quchi(LI 11)acupoints every other week from day 8.Mice in the AD with sham-acupoint catgut-embedding treatment group underwent the same procedure as the ADA group but without catgut implantation.Severity was assessed using SCORAD on treatment days 1,10,and 20.On day 18,nine mice per group were euthanized,and the remaining on day 28.Histopathological changes were observed using hematoxylin-eosin and immunohistochemistry staining.TNF-α,IL-4,IL-6,and IL-13 levels were analyzed by ELISA,and GATA3 and STAT6 protein levels by western blot.Results:After 20 days of acupoint catgut-embedding therapy treatment,mice showed reduced dermatitis scores compared to DNCB-induced AD-like mice.Significant decreases occurred in serum IL-4,IL-6,IL-13,and TNF-αlevels.Skin analysis revealed marked reductions in CD4^(+)and CD8^(+)cell infiltration,as well as GATA3 and STAT6 protein levels.Conclusion:Acupoint catgut-embedding therapy may effectively alleviate atopic dermatitis by suppressing Th2 immune responses via the STAT6-GATA3 pathway and reducing CD4^(+)and CD8^(+)T cell infiltration in skin lesions.

Engineering W/O/W pickering emulsion for the enhanced antigen delivery and immune responses

Tumor immunotherapy,particularly cancer vaccines,holds promise for combating cancer by harnessing tailored immune responses against malignant cells.However,conventional approaches face challenges in efficiently delivering antigens for optimal immune activation.Emulsion adjuvants,like MF59,enhance cellular uptake but struggle to induce robust CD8^(+)T cell responses.Here,we introduce a novel strategy employing a water-in-oil-in-water(W/O/W)multiple Pickering emulsion(mPE)for antigen delivery.The mPE,utilizing biocompatible,pH-sensitive particles,encapsulates antigens within the inner water phase,ensuring enhanced intracellular processing and dictating the intracellular fate of antigens for improved cross-presentation.In vitro and in vivo studies demonstrated that mPEs induced robust dendritic cells activation and antigen cross-presentation,leading to a significantly enhanced immune response.Notably,calcium phosphate-stabilized mPE(CaP-mPE)illustrated the more robust IFN-γ^(+)T cell responses.In comparison with traditional surfactant-stabilized multiple emulsions,CaP-mPE significantly inhibit tumor growth and effectively prolong the survival of tumor-bearing mice.This innovative approach offers a promising avenue for the development of effective cancer vaccines with potent cellular immune responses.

Effects of Mycotoxin from Maize on Immune Response of Vaccine for Piglets

[Objective] The aim of this study was to investigate the effects of mycotoxin from moldy maize on immune response of piglets.[Method] ELISA method was used to determine the content of Aflatoxin B1 and ochratoxin A in maize; after the piglets were fed with the moldy maize,the corresponding antibody titers in the serums of piglets were measured.[Result] Antibody levels of tested group were obvious lower than that of the control,while the histological section of immune organs also suggested that mycotoxin could significantly inhibit the immune response of piglets.[Conclusion] Mycotoxin in maize had important effects on the internal organs and immune response of piglets.

Effects of Immunological Stress on Immune Response in Different Breeds of Piglets

[ Objective] The research aimed to explore effects of an immunological stress on immune response in different breeds of piglets （ Lulai pig, Laiwu pig and Yorkshire pig）. [Method] All the 12 weaning pigs （Lulai pig, Laiwu pig and Yorkshire pig） weighing （12.6 ±0.5） kg were used in a 2 x3 factorial design. The main factors consisted of immunological challenge （ LPS or saline） and breeds （ Lulai pig, Laiwu pig and Yorkshire pig）. On Day 1, six piglets of each breed were injected with LPS at the usage of 200 μg/kg BW or an equivalent amount of sterile saline, and in jected classical swine fever vaccine at the same time. Blood sample were collected on Day 2, 7 and 14 post injection to analyze the blood lympho cyte proliferation. The levels of antibodies against classical swine fever were tested on Day 1 prior to injection and on Day 7 and 14 post injection. [ Result] On Day 2 after injection, the lymphocyte transformation rate of piglets injected with LPS were significantly （P〈O. 01 ） increased compared with piglets injected with saline. The lymphocyte transformation rate of Laiwu piglets was significant higher than that of Yorkshire piglets （ P 〈 0.05）. Effects of immunological stress on the level of antibodies against classical swine fever were not significantly different among different breeds of pig lets. [ Conclusion] LPS can effectively stimulate cellular immunity response in different breeds of piglets, and the immune response ability is different among various breeds of piglets.

Prognostic value of changes in serum carcinoembryonic antigen levels for preoperative chemoradiotherapy response in locally advanced rectal cancer

BACKGROUND Preoperative chemoradiotherapy(CRT)is a standard treatment modality for locally advanced rectal cancer.However,CRT alone cannot improve overall survival.Approximately 20%of patients with CRT-resistant tumors show disease progression.Therefore,predictive factors for treatment response are needed to identify patients who will benefit from CRT.We theorized that the prognosis may vary if patients are classified according to pre-to post-CRT changes in carcinoembryonic antigen(CEA)levels.AIM To identify patients with locally advanced rectal cancer for preoperative chemoradiotherapy based on carcinoembryonic antigen levels.METHODS We retrospectively included locally advanced rectal cancer patients who underwent preoperative CRT and curative resection between 2011 and 2017.Patients were assigned to groups A,B,and C based on pre-and post-CRT serum CEA levels:Both>5;pre>5 and post≤5;and both≤5 ng/mL,respectively.We compared the response to CRT based on changes in serum CEA levels.Receiver operating characteristic curve analysis was performed to determine optimal cutoff for neutrophil–lymphocyte ratio and platelet–lymphocyte ratio.Multivariate logistic regression analysis was used to evaluate the prognostic factors for pathologic complete response(pCR)/good response.RESULTS The cohort comprised 145 patients;of them,27,43,and 65 belonged to groups A,B,and C,respectively,according to changes in serum CEA levels before and after CRT.Pre-(P<0.001)and post-CRT(P<0.001)CEA levels and the ratio of downstaging(P=0.013)were higher in Groups B and C than in Group A.The ratio of pathologic tumor regression grade 0/1 significantly differed among the groups(P=0.003).Group C had the highest number of patients showing pCR(P<0.001).Most patients with pCR showed pre-and post-CRT CEA levels<5 ng/mL(P<0.001,P=0.008).Pre-and post-CRT CEA levels were important risk factors for pCR(OR=18.71;95%CI:4.62–129.51,P<0.001)and good response(OR=5.07;95%CI:1.92–14.83,P=0.002),respectively.Pre-CRT neutrophil–lymphocyte ratio and post-CRT T≥3 stage were also prognostic factors for pCR or good response.CONCLUSION Pre-and post-CRT CEA levels,as well as change in CEA levels,were prognostic markers for treatment response to CRT and may facilitate treatment individualization for rectal cancer.

DYNAMICS ANALYSIS OF A DELAYED HIV INFECTION MODEL WITH CTL IMMUNE RESPONSE AND ANTIBODY IMMUNE RESPONSE

In this paper,dynamics analysis of a delayed HIV infection model with CTL immune response and antibody immune response is investigated.The model involves the concentrations of uninfected cells,infected cells,free virus,CTL response cells,and antibody antibody response cells.There are three delays in the model:the intracellular delay,virus replication delay and the antibody delay.The basic reproductive number of viral infection,the antibody immune reproductive number,the CTL immune reproductive number,the CTL immune competitive reproductive number and the antibody immune competitive reproductive number are derived.By means of Lyapunov functionals and LaSalle’s invariance principle,sufficient conditions for the stability of each equilibrium is established.The results show that the intracellular delay and virus replication delay do not impact upon the stability of each equilibrium,but when the antibody delay is positive,Hopf bifurcation at the antibody response and the interior equilibrium will exist by using the antibody delay as a bifurcation parameter.Numerical simulations are carried out to justify the analytical results.

Apparent dose dependent antibody response in chickens immunized with orthopox virus antigens

Dose-dependent IgY antibody response to different amounts oforthopox virus （OPV） antigen has been studied in immunized chickens for two different OPV strains （vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9.2× 10^7PFU）. The antibody responses to different immunizations were tested and compared by indirect immunofluorescence antibody test. Our results, together with the literature, show that the antigen dose used for immunization plays an important role for the production of specific Abs. An increase in antigen concentration may achieve higher Ab titers but, dependent on the immunogenicity of OPV antigen, it can also lead to an immune depression. However, in this study we found that OPV played a positive correlation between antigen concentration and Ab-titer.

Dynamics of host immune responses to SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the most recent global health threat,is spreading throughout the world with worrisome speed,and the current wave of coronavirus disease 2019(COVID-19)seems to have no mercy.While this mysterious virus challenges our ability to control viral infections,our opportunities to control the COVID-19 pandemic are gradually fading.Currently,pandemic management relies on preventive interventions.Although prevention is a good strategy to mitigate SARS-CoV-2 transmission,it still cannot be considered an absolute solution to eliminate this pandemic.Currently,developing a potent immunity against this viral infection seems to be the most promising strategy to drive down this ongoing global tragedy.However,with the emergence of new challenges in the context of immune responses to COVID-19,the road to control this devastating pandemic seems bumpier;thus,it is pivotal to characterize the dynamics of host immune responses to COVID-19,in order to develop efficient prophylactic and therapeutic tools.This begs the question of whether the effector mechanisms of the immune system are indeed potent or a possible contributing factor to developing more severe and lethal forms of COVID-19.In this review,the possible role of the immunopathologic phenomena including antibody-dependent enhancement,cytokine storm,and original antigenic sin in severity and mortality of COVID-19 will be discussed.

Hepatitis B virus S gene enhances immune responses of a multiple-epitope DNA construct of hepatitis C virus in mice

The purpose of this study was to construct an eukaryotic DNA vector encoding a multiple-epitope antigen (MFC) of hepatitis C virus (HCV) and a hepatitis B surface antigen (HBsAg) , and explore the effect of HBsAg gene on the immunity of HCV multiple-epitope DNA construct in vitro and in vivo in mice. An HCV DNA vector (pVAX1-HBs-MFC) was constructed by fusing HBsAg gene to the N-terminal of an HCV multiple-epitope antigen gene. The pVAX1-HBs-MFC was transfected into HEK 293T cells and its expression was measured by ELISA and Western blotting. BALB/c mice were intramuscularly immunized with the pVAX1-HBs-MFC, and an ELISA approach was applied to determine the specific antibody titers and subtypes in the mouse serum. The cross-reactivity of the antibodies was also checked with two synthesized HCV hypervariable region 1 (HVR1) peptides. The IFN-γ production and cell proliferation of the mouse spleen cells were evaluated by ELISA and MTS (3-[4, 5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl] -2H-tetrazolium, inner salt) assays, respectively. The expression of pVAX1-HBs-MFC was detectable in the transfected HEK 293T cells. The serum antibody response was effectively elicited in BALB/c mice injected with pVAX1-HBs-MFC. The highest titer of antibody against HCV (MFC) was 1∶1280, and the ratio of IgG2a/IgG1 was 1.50±0.12 at the fifth week after first immunization. Moreover, the collected mouse serum antibody had the ability to cross-react with the two synthesized HCV HVR1 peptides. The stimulation index of the mouse splenocytes to MFC was 1.79 ±0.07, and the IFN-γ level was 287±6?pg/ml at week 21 after first immunization. The highest titer of the antibody in control BALB/c mice immunized with pVAX1-MFC was 1∶320, and the ratio of IgG2a/IgG1 was 1.33±0.11 at week 5 post-immunization. Furthermore, the stimulation index of the mouse splenocytes cells to MFC was 1.52±0.06, and the IFN-γ level was 225±9.3?pg/ml at week 21 post-immunization. The HBsAg gene can enhance the effects of an HCV multiple-epitope DNA construct on its humoral and cellular immune responses. This HBsAg enhanced HCV multiple-epitope DNA vector may be of potential use in the development of HCV vaccines.

Antigen epitopes of animal coronaviruses:a mini-review

Coronaviruses are widespread in nature and can infect mammals and poultry,making them a public health concern.Globally,prevention and control of emerging and re-emerging animal coronaviruses is a great challenge.The mecha-nisms of virus-mediated immune responses have important implications for research on virus prevention and control.The antigenic epitope is a chemical group capable of stimulating the production of antibodies or sensitized lympho-cytes,playing an important role in antiviral immune responses.Thus,it can shed light on the development of diagnos-tic methods and novel vaccines.Here,we have reviewed advances in animal coronavirus antigenic epitope research,aiming to provide a reference for the prevention and control of animal and human coronaviruses.

Effects of thymol and carvacrol supplementation on intestinal integrity and immune responses of broiler chickens challenged with Clostridium perfringens

Background： Necrotic enteritis caused by Clostfidium perffingens infection leads to serious economic losses in the global poultry production. In the present study, we investigated the protective effects of essential oils （EO, which contained 25 % thymol and 25 % carvacrol as active components） supplementation on growth performance, gut lesions, intestinal morphology, and immune responses of the broiler chickens infected with C. perfringens. A total of 448 1-day-old male broiler chicks were allocated into eight treatment groups following a 4 x 2 factorial arrangement with four dietary EO dosages （0, 60, 120, or 240 mg/kg） and two infection status （with or without C. perfringens challenge from d 14 to 20）. Results： The challenge did not impair the growth performance of birds, but induced gut lesions and increased crypt depth in the ileum （P ≤ 0.05）. It also down-regulated the claudin-1 and occludin mRNA expression （P ≤0.05）, up-regulated the mRNA expression of interleukin-113 （P≤ 0.05）, tended to increase the toll-like receptor （TLR） 2 mRNA expression （P 〈 0.10） in the ileum, and enhanced the mucosal secretory IgA production （P 〈 0.05）. In the challenged birds, dietary EO supplementation linearly alleviated the gut lesions and improved the ratio of villus height to crypt depth （P ≤0.05）, and the supplementation of 120 and 240 mg/kg EO increased the serum antibody titers against Newcastle disease virus （P≤ 0.05）. Regardless of challenge, the EO supplementation showed a tendency to linearly elevate the feed conversion efficiency between 14 and 28 d of age as well as the occludin mRNA expression （P〈 0.10）, and linearly inhibited the mRNA expression of TLR2 and tumor necrotic factor-o in the ileum （P≤ 0.05）. Conclusions： The dietary supplementation of EO could alleviate the intestinal injury by improving intestinal integrity and modulating immune responses in the C. perffingens-challenged broiler chickens.

Orchestrating antigen delivery and presentation efficiency in lymph node by nanoparticle shape for immune response

Activating humoral and cellular immunity in lymph nodes(LNs)of nanoparticle-based vaccines is critical to controlling tumors.However,how the physical properties of nanovaccine carriers orchestrate antigen capture,lymphatic delivery,antigen presentation and immune response in LNs is largely unclear.Here,we manufactured gold nanoparticles(AuNPs)with the same size but different shapes(cages,rods,and stars),and loaded tumor antigen as nanovaccines to explore their disparate characters on above four areas.Results revealed that star-shaped AuNPs captured and retained more repetitive antigen epitopes.On lymphatic delivery,both rods and star-shaped nanovaccines mainly drain into the LN follicles region while cage-shaped showed stronger paracortex retention.A surprising finding is that the star-shaped nanovaccines elicited potent humoral immunity,which is mediated by CD4^(+)T helper cell and follicle B cell cooperation significantly preventing tumor growth in the prophylactic study.Interestingly,cage-shaped nanovaccines preferentially presented peptide-MHC I complexes to evoke robust CD8^(+)T cell immunity and showed the strongest therapeutic efficacy when combined with the PD-1 checkpoint inhibitor in established tumor study.These results highlight the importance of nanoparticle shape on antigen delivery and presentation for immune response in LNs,and our findings support the notion that different design strategies are required for prophylactic and therapeutic vaccines.

Effects of dietary supplementation of probiotic,Clostridium butyricum,on growth performance,immune response,intestinal barrier function,and digestive enzyme activity in broiler chickens challenged with Escherichia coli K88

Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varying degrees of resistance to different antibiotics. Therefore the use of probiotics is becoming accepted as an alternative to antibiotics. In this study, we evaluated the effects of Clostfidium butyricum （C. butyficum） on growth performance, immune response, intestinal barrier function, and digestive enzyme activity in broiler chickens challenged with Eschefichia coli （E. coil） K88. Methods： The chickens were randomly divided into four treatment groups for 28 days. Negative control treatment （NC） consisted of birds fed a basal diet without E. coil K88 challenge and positive control treatment （PC） consisted of birds fed a basal diet and challenged with E. coil K88. C. buO/ricum probiotic treatment （CB） consisted of birds fed a diet containing 2 x 107 cfu C. buO/ricum/kg of diet and challenged with E. coil K88. Colistin sulfate antibiotic treatment （CS） consisted of birds fed a diet containing 20 mg colistin sulfate/kg of diet and challenged with E. coil K88. Results： The body weight （BW） and average day gain （ADG） in the broilers of CB group were higher （P 〈 0.05） than the broilers in the PC group overall except the ADG in the 14-21 d post-challenge. The birds in CB treatment had higher （P 〈 0.05） concentration of tumor necrosis factor-a （TNF-a） at 3 and 7 d post-challenge, and higher （P 〈 0.05） concentration of interleukin-4 （IL-4） at 14 d post-challenge than those in the PC treatment group. The concentration of serum endotoxin in CB birds was lower （P 〈 0.05） at 21 d post-challenge, and the concentrations of serum diamine oxidase in CB birds were lower （P 〈 0.05） at 14 and 21 d post-challenge than in PC birds. Birds in CB treatment group had higher （P 〈 0.05） jejunum villi height than those in PC, NC, or CS treatment at 7, 14, and 21 d post-challenge. In comparison to PC birds, the CB birds had lower （P 〈 0.05） jejunum crypt depth during the whole experiment. The birds in CB or CS treatment group had higher （P 〈 0.05） activities of amylase and protease at 3, 7, and 14 d post-challenge, and higher （P 〈 0.05） activity of lipase at 3, 7 d post-challenge than PC birds.