Objective: To investigate human cytomegalovirus infec-tion and genetic variations in glycoprotein B(gB) inliver transplant recipients in south-east China.Methods:EDTA-blood samples were obtained from 21liver transplan...Objective: To investigate human cytomegalovirus infec-tion and genetic variations in glycoprotein B(gB) inliver transplant recipients in south-east China.Methods:EDTA-blood samples were obtained from 21liver transplant recipients. The semi-nested PCR wasused to amplify a region of high sequence variabilityin the gB gene of human cytomegalovirus (HCMV)followed by direct sequence analysis.Results: Out of the 21 liver transplant recipients, 5were proved HCMV positive 62 to 180 days aftertransplantation. The nucleotide and encoded aminoacid sequences were compared with published se-quences of AD169 and Towne laboratory strains.Within the region sequenced, 2 out of 5 strains pos-sessed a peptide configuration similar to that of strainAD169, while another 2 strains displayed a peptideconfiguration similar to that of strain Towne. Onestrain had amino acid substitution, which was differ-ent from those of both AD169 and Towne in thecleavage site.Conclusion: Our results provide molecular epidemio-logical data for HCMV strains circulating among trans-plant recipients in south-east China.展开更多
Infections caused by intracellular bacterial pathogens are difficult to treat since most antibiotics have low cell permeability and undergo rapid degradation within cells.The rapid development and dissemination of ant...Infections caused by intracellular bacterial pathogens are difficult to treat since most antibiotics have low cell permeability and undergo rapid degradation within cells.The rapid development and dissemination of antimicrobial–resistant strains have exacerbated this dilemma.With the increasing knowledge of host–pathogen interactions,especially bacterial strategies for survival and proliferation within host cells,host-directed therapy(HDT)has attracted increased interest and has emerged as a promising antiinfection method for treating intracellular infection.Herein,we applied a cell-based screening approach to a US Food and Drug Administration(FDA)-approved drug library to identify compounds that can inhibit the intracellular replication of Salmonella Typhimurium(S.Typhimurium).This screening allowed us to identify the antidiarrheal agent loperamide(LPD)as a potent inhibitor of S.Typhimurium intracellular proliferation.LPD treatment of infected cells markedly promoted the host autophagic response and lysosomal activity.A mechanistic study revealed that the increase in host autophagy and elimination of intracellular bacteria were dependent on the high expression of glycoprotein nonmetastatic melanoma protein B(GPNMB)induced by LPD.In addition,LPD treatment effectively protected against S.Typhimurium infection in Galleria mellonella and mouse models.Thus,our study suggested that LPD may be useful for the treatment of diseases caused by intracellular bacterial pathogens.Moreover,LPD may serve as a promising lead compound for the development of anti-infection drugs based on the HDT strategy.展开更多
Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices,...Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in the field. In the present study, we generated NDV LaSota vaccine strain-based recombinant viruses expressing the glycoprotein (G) of aMPV, subtype A or B, using reverse genetics technology. These recombinant viruses, rLS/aMPV-A G and rLS/aMPV-B G, were characterized in cell cultures and evaluated in turkeys as bivalent, next-generation vaccines. The results showed that these recombinant vaccine candi-dates were slightly attenuated in vivo, yet maintained similar growth dynamics, cytopathic effects, and virus titers in vitro when compared to the parental LaSota virus. The expression of the aMPV G protein in recombinant virus-infected cells was detected by immunofluorescence. Vaccination of turkeys with rLS/aMPV-A G or rLS/aMPV-B G conferred complete protection against velogenic NDV, CA02 strain challenge and partial protection against homologous patho-genic aMPV challenge. These results suggest that the LaSota recombinant virus is a safe and effective vaccine vector and expression of the G protein alone is not sufficient to provide full protection against aMPV-A or -B infections. Ex-pression of other aMPV-A or -B virus immunogenic protein(s) individually or in conjunction with the G protein may be necessary to induce stronger and more protective immunity against aMPV diseases.展开更多
糖蛋白非转移性黑色素瘤蛋白B(glycoprotein non-metastatic melanoma protein B,GPNMB)是一种I型跨膜蛋白,多富集在癌细胞表面,在巨噬细胞和小胶质细胞中呈高表达。GPNMB在肿瘤进展及免疫反应中发挥了重要作用,其胞外结构域与整合素相...糖蛋白非转移性黑色素瘤蛋白B(glycoprotein non-metastatic melanoma protein B,GPNMB)是一种I型跨膜蛋白,多富集在癌细胞表面,在巨噬细胞和小胶质细胞中呈高表达。GPNMB在肿瘤进展及免疫反应中发挥了重要作用,其胞外结构域与整合素相互作用,能促进免疫抑制,并能促进血管生成细胞募集到肿瘤微环境,从而影响肿瘤的免疫反应,有可能可作为免疫治疗及靶向治疗的潜在靶点。展开更多
Chronic infection by either hepatitis B virus(HBV)or hepatitis C virus(HCV)share epidemiological characteristics with risks for development of severe complications such as liver cirrhosis and hepatocellular carcinoma....Chronic infection by either hepatitis B virus(HBV)or hepatitis C virus(HCV)share epidemiological characteristics with risks for development of severe complications such as liver cirrhosis and hepatocellular carcinoma.HBV and HCV also share a high genetic variability. Among highly variable regions,viral genes encoding surface proteins(hepatitis B surface antigen,E1/E2 HCV glycoproteins)play key roles in the stimulation of the host-related immune response and viral entry into hepatocytes.Specific segments of HBV envelope proteins(preS1,"a"determinant)are crucial in the entry process into permissive cells.HCV entry is a complex multistep process involving multiple cell cofactors (glycosaminoglycans,low density lipoprotein receptor, SR-B1,CD81,claudin-1,occludin,EGFR,EphA2)in the interaction with HCV E1/E2 envelope glycoproteins.In vitro both viruses can be controlled by antibody-me-diated neutralization targeting viral envelope,also essential in preventing HBV infection in vivo as observed through successful vaccination using HBs antigen.But preventive vaccination and/or therapeutic pressure can influence HBV and HCV variability.For HBV,the patterns of antiviral drug resistance in chronic hepatitis are complex and the original pol/S gene overlap has to be taken into account.Treatment-induced HBV mutations in pol could indeed generate S mutants with subsequent modified antigenicity or increased cancer induction.Variability of HBV and HCV envelope proteins combining high exposure to selective pressures and crucial functional roles require investigation in the context of diagnostic,vaccination and treatment tools.In this editorial a synthesis is performed of HBV and HCV envelope properties at the entry step and as antigenic proteins,and the subsequent clinical impact.展开更多
文摘Objective: To investigate human cytomegalovirus infec-tion and genetic variations in glycoprotein B(gB) inliver transplant recipients in south-east China.Methods:EDTA-blood samples were obtained from 21liver transplant recipients. The semi-nested PCR wasused to amplify a region of high sequence variabilityin the gB gene of human cytomegalovirus (HCMV)followed by direct sequence analysis.Results: Out of the 21 liver transplant recipients, 5were proved HCMV positive 62 to 180 days aftertransplantation. The nucleotide and encoded aminoacid sequences were compared with published se-quences of AD169 and Towne laboratory strains.Within the region sequenced, 2 out of 5 strains pos-sessed a peptide configuration similar to that of strainAD169, while another 2 strains displayed a peptideconfiguration similar to that of strain Towne. Onestrain had amino acid substitution, which was differ-ent from those of both AD169 and Towne in thecleavage site.Conclusion: Our results provide molecular epidemio-logical data for HCMV strains circulating among trans-plant recipients in south-east China.
基金supported by the National Key Research and Development Program of China(2021YFD1801000)the Natural Science Foundation of China(32373066)+1 种基金the Natural Science Foundation of Jilin Province(20230101142JC)the Fundamental Research Funds for the Central Universities.
文摘Infections caused by intracellular bacterial pathogens are difficult to treat since most antibiotics have low cell permeability and undergo rapid degradation within cells.The rapid development and dissemination of antimicrobial–resistant strains have exacerbated this dilemma.With the increasing knowledge of host–pathogen interactions,especially bacterial strategies for survival and proliferation within host cells,host-directed therapy(HDT)has attracted increased interest and has emerged as a promising antiinfection method for treating intracellular infection.Herein,we applied a cell-based screening approach to a US Food and Drug Administration(FDA)-approved drug library to identify compounds that can inhibit the intracellular replication of Salmonella Typhimurium(S.Typhimurium).This screening allowed us to identify the antidiarrheal agent loperamide(LPD)as a potent inhibitor of S.Typhimurium intracellular proliferation.LPD treatment of infected cells markedly promoted the host autophagic response and lysosomal activity.A mechanistic study revealed that the increase in host autophagy and elimination of intracellular bacteria were dependent on the high expression of glycoprotein nonmetastatic melanoma protein B(GPNMB)induced by LPD.In addition,LPD treatment effectively protected against S.Typhimurium infection in Galleria mellonella and mouse models.Thus,our study suggested that LPD may be useful for the treatment of diseases caused by intracellular bacterial pathogens.Moreover,LPD may serve as a promising lead compound for the development of anti-infection drugs based on the HDT strategy.
文摘Avian metapneumovirus (aMPV) and Newcastle disease virus (NDV) are threatening avian pathogens that can cause serious respiratory diseases in poultry worldwide. Vaccination, combined with strict biosecurity practices, has been the recommendation for controlling these diseases in the field. In the present study, we generated NDV LaSota vaccine strain-based recombinant viruses expressing the glycoprotein (G) of aMPV, subtype A or B, using reverse genetics technology. These recombinant viruses, rLS/aMPV-A G and rLS/aMPV-B G, were characterized in cell cultures and evaluated in turkeys as bivalent, next-generation vaccines. The results showed that these recombinant vaccine candi-dates were slightly attenuated in vivo, yet maintained similar growth dynamics, cytopathic effects, and virus titers in vitro when compared to the parental LaSota virus. The expression of the aMPV G protein in recombinant virus-infected cells was detected by immunofluorescence. Vaccination of turkeys with rLS/aMPV-A G or rLS/aMPV-B G conferred complete protection against velogenic NDV, CA02 strain challenge and partial protection against homologous patho-genic aMPV challenge. These results suggest that the LaSota recombinant virus is a safe and effective vaccine vector and expression of the G protein alone is not sufficient to provide full protection against aMPV-A or -B infections. Ex-pression of other aMPV-A or -B virus immunogenic protein(s) individually or in conjunction with the G protein may be necessary to induce stronger and more protective immunity against aMPV diseases.
文摘糖蛋白非转移性黑色素瘤蛋白B(glycoprotein non-metastatic melanoma protein B,GPNMB)是一种I型跨膜蛋白,多富集在癌细胞表面,在巨噬细胞和小胶质细胞中呈高表达。GPNMB在肿瘤进展及免疫反应中发挥了重要作用,其胞外结构域与整合素相互作用,能促进免疫抑制,并能促进血管生成细胞募集到肿瘤微环境,从而影响肿瘤的免疫反应,有可能可作为免疫治疗及靶向治疗的潜在靶点。
文摘Chronic infection by either hepatitis B virus(HBV)or hepatitis C virus(HCV)share epidemiological characteristics with risks for development of severe complications such as liver cirrhosis and hepatocellular carcinoma.HBV and HCV also share a high genetic variability. Among highly variable regions,viral genes encoding surface proteins(hepatitis B surface antigen,E1/E2 HCV glycoproteins)play key roles in the stimulation of the host-related immune response and viral entry into hepatocytes.Specific segments of HBV envelope proteins(preS1,"a"determinant)are crucial in the entry process into permissive cells.HCV entry is a complex multistep process involving multiple cell cofactors (glycosaminoglycans,low density lipoprotein receptor, SR-B1,CD81,claudin-1,occludin,EGFR,EphA2)in the interaction with HCV E1/E2 envelope glycoproteins.In vitro both viruses can be controlled by antibody-me-diated neutralization targeting viral envelope,also essential in preventing HBV infection in vivo as observed through successful vaccination using HBs antigen.But preventive vaccination and/or therapeutic pressure can influence HBV and HCV variability.For HBV,the patterns of antiviral drug resistance in chronic hepatitis are complex and the original pol/S gene overlap has to be taken into account.Treatment-induced HBV mutations in pol could indeed generate S mutants with subsequent modified antigenicity or increased cancer induction.Variability of HBV and HCV envelope proteins combining high exposure to selective pressures and crucial functional roles require investigation in the context of diagnostic,vaccination and treatment tools.In this editorial a synthesis is performed of HBV and HCV envelope properties at the entry step and as antigenic proteins,and the subsequent clinical impact.
