Equine Infectious Anemia Virus (EIAV) is a retrovirus that establishes a persistent infection in horses and ponies. The virus is in the same lentivirus subgroup that includes human immunodeficiency virus (HIV). The si...Equine Infectious Anemia Virus (EIAV) is a retrovirus that establishes a persistent infection in horses and ponies. The virus is in the same lentivirus subgroup that includes human immunodeficiency virus (HIV). The similarities between these two viruses make the study of the immune response to EIAV relevant to research on HIV. We developed a mathematical model of within-host EIAV infection dynamics that contains both humoral and cell-mediated immune responses. Analysis of the model yields results on thresholds that would be necessary for a combined immune response to successfully control infection. Numerical simulations are presented to illustrate the results. These findings have the potential to lead to immunological control measures for lentiviral infection.展开更多
Objective:To delineate immunomodulatory role of histamine on antibody generation pr of ile in rabbit in the present dose-dependent histamine study.Methods:The cohort comprised of three groups(Ⅲ,ⅣandⅤ),containing si...Objective:To delineate immunomodulatory role of histamine on antibody generation pr of ile in rabbit in the present dose-dependent histamine study.Methods:The cohort comprised of three groups(Ⅲ,ⅣandⅤ),containing six rabbits each,and received subcutaneous histamine 50μg/kg×bis in die(b.i.d.),100μg/kg×b.i.d.and 200μg/kg X b.i.d.,respectively for 10 days (starting from the 1st day).They were subsequently immunized on the 3rd day with intravenous injection of sheep blood cell(SRBC)(1×10 cells/mL).GroupⅡ(positive control)(n=6) received vehicle(sterile distilled water) and immunized at day 3 similarly while groupⅠ(negative control) (n=6) remained non-immunized and received only vehicle.All experimentations were performed in triplicate.Blood samples were collected on pre-immunization(pre-I)(day 0),as well as on days 7-,14-,21-,28- and 58- post-immunization(post-I).Immunological parameters[total immunoglobulins(Igs),IgM and IgG]were analyzed by enzyme linked immunosorbent assay (ELISA) technique.Results:Histamine could influence a detectable antibody response to SRBC as early as day 7-post-I,which lasted until day 58- post-I.The results were found statistically significant(P【 0.05).Conclusions:Our results provide evidence that histamine has a short-term effect on antibody generation(until its presence in the body),and the antibody generation titer in vivo were affected by the concentration of histamine.展开更多
Children with Coronavirus Disease 2019(COVID-19) were reported to show milder symptoms and better prognosis than their adult counterparts, but the difference of immune response against SARS-CoV-2 between children and ...Children with Coronavirus Disease 2019(COVID-19) were reported to show milder symptoms and better prognosis than their adult counterparts, but the difference of immune response against SARS-CoV-2 between children and adults hasn’t been reported. Therefore we initiated this study to figure out the features of immune response in children with COVID-19.Sera and whole blood cells from 19 children with COVID-19 during different phases after disease onset were collected.The cytokine concentrations, SARS-CoV-2 S-RBD or N-specific antibodies and T cell immune responses were detected respectively. In children with COVID-19, only 3 of 12 cytokines were increased in acute sera, including interferon(IFN)-cinduced protein 10(IP10), interleukin(IL)-10 and IL-16. We observed an increase in T helper(Th)-2 cells and a suppression in regulatory T cells(Treg) in patients during acute phase, but no significant response was found in the IFN-cproducing or tumor necrosis factor(TNF)-a-producing CD8?T cells in patients. S-RBD and N IgM showed an early induction, while S-RBD and N IgG were prominently induced later in convalescent phase. Potent S-RBD IgA response was observed but N IgA seemed to be inconspicuous. Children with COVID-19 displayed an immunophenotype that is less inflammatory than adults, including unremarkable cytokine elevation, moderate CD4?T cell response and inactive CD8?T cell response, but their humoral immunity against SARS-CoV-2 were as strong as adults. Our finding presented immunological characteristics of children with COVID-19 and might give some clues as to why children develop less severe disease than adults.展开更多
The role of anti-tumor immune responses in oncolytic adenoviral therapy has not been well studied due to lack of efficacious tu- mor model in immunocompetent mice.Here,we evaluated the contributions of immune componen...The role of anti-tumor immune responses in oncolytic adenoviral therapy has not been well studied due to lack of efficacious tu- mor model in immunocompetent mice.Here,we evaluated the contributions of immune components to the therapeutic effects of oncolytic adenoviruse in an immunocompetent murine tumor model permissive for infection and replication of adenovirus.We found that CD8+T cells were critical mediator for antitumor efficacy by oncolytic adenovirus.Intratumoral viral therapy induced intensive infiltration of CD8+T cells in tumor,increased tumor-specific IFN-?(interferon-?)production and CTL(cytotoxic T lymphocyte)activity of lymphocytes,and generated a long-term tumor-specific immune memory.Boosting CD8+T cell responses by agonistic anti-4-1BB(cluster differentiation 137,CD137)antibody showed synergistic anticancer effects with oncolytic viro- therapy.Our results provide insight into antitumor mechanisms of oncolytic adenovirus in addition to their direct oncolytic effect.展开更多
Mutations in SARS-CoV-2 variants of concern(VOCs)have enhanced transmissibility and immune evasion with respect to current vaccines and neutralizing antibodies(NAbs).How naturally occurring spike mutations affect the ...Mutations in SARS-CoV-2 variants of concern(VOCs)have enhanced transmissibility and immune evasion with respect to current vaccines and neutralizing antibodies(NAbs).How naturally occurring spike mutations affect the infectivity and antigenicity of VOCs remains to be investigated.The entry efficiency of individual spike mutations was determined in vitro using pseudotyped viruses.BALB/c mice were immunized with 2-dose DNA vaccines encoding B.1.1.7,B.1.351,B.1.1.529 and their single mutations.Cellular and humoral immune responses were then compared to determine the impact of individual mutations on immunogenicity.In the B.1.1.7 lineage,Del69–70 and Del 144 in NTD,A570D and P681H in SD1 and S982A and D1118H in S2 significantly increased viral entry,whereas T716I resulted in a decrease.In the B.1.351 lineage,L18F and Del 242–244 in the NTD,K417N in the RBD and A701V in S2 also increased viral entry.S982A weakened the generation of binding antibodies.All sera showed reduced cross-neutralization activity against B.1.351,B.1.617.2(Delta)and B.1.1.529(Omicron BA.1).S982A,L18F,and Del 242–244 hindered the induction of cross-NAbs,whereas Del 69–70,Del144,R246I,and K417N showed the opposite effects.B.1.351 elicited adequate broad cross-NAbs against both B.1.351 and B.1.617.2.All immunogens tested,however,showed low neutralization against circulating B.1.1.529.In addition,T-cell responses were unlikely affected by mutations tested in the spike.We conclude that individual spike mutations influence viral infectivity and vaccine immunogenicity.Designing VOC-targeted vaccines is likely necessary to overcome immune evasion from current vaccines and neutralizing antibodies.展开更多
文摘Equine Infectious Anemia Virus (EIAV) is a retrovirus that establishes a persistent infection in horses and ponies. The virus is in the same lentivirus subgroup that includes human immunodeficiency virus (HIV). The similarities between these two viruses make the study of the immune response to EIAV relevant to research on HIV. We developed a mathematical model of within-host EIAV infection dynamics that contains both humoral and cell-mediated immune responses. Analysis of the model yields results on thresholds that would be necessary for a combined immune response to successfully control infection. Numerical simulations are presented to illustrate the results. These findings have the potential to lead to immunological control measures for lentiviral infection.
基金University Grants Commission, New Delhi,India for providing UGC Fellowship[UGC letter DON F.19-33/2006(CU)]M.Shahid is grateful to Department of Science & Technology,Ministry of Science & Technology,Government of India for awarding"Young Scientist Project Award"(FT/SR-L-111/2006)
文摘Objective:To delineate immunomodulatory role of histamine on antibody generation pr of ile in rabbit in the present dose-dependent histamine study.Methods:The cohort comprised of three groups(Ⅲ,ⅣandⅤ),containing six rabbits each,and received subcutaneous histamine 50μg/kg×bis in die(b.i.d.),100μg/kg×b.i.d.and 200μg/kg X b.i.d.,respectively for 10 days (starting from the 1st day).They were subsequently immunized on the 3rd day with intravenous injection of sheep blood cell(SRBC)(1×10 cells/mL).GroupⅡ(positive control)(n=6) received vehicle(sterile distilled water) and immunized at day 3 similarly while groupⅠ(negative control) (n=6) remained non-immunized and received only vehicle.All experimentations were performed in triplicate.Blood samples were collected on pre-immunization(pre-I)(day 0),as well as on days 7-,14-,21-,28- and 58- post-immunization(post-I).Immunological parameters[total immunoglobulins(Igs),IgM and IgG]were analyzed by enzyme linked immunosorbent assay (ELISA) technique.Results:Histamine could influence a detectable antibody response to SRBC as early as day 7-post-I,which lasted until day 58- post-I.The results were found statistically significant(P【 0.05).Conclusions:Our results provide evidence that histamine has a short-term effect on antibody generation(until its presence in the body),and the antibody generation titer in vivo were affected by the concentration of histamine.
基金supported by grants specific for Coronavirus Disease 2019 from the Children’s Hospital of Fudan University (Grant No. EKXGZX006)。
文摘Children with Coronavirus Disease 2019(COVID-19) were reported to show milder symptoms and better prognosis than their adult counterparts, but the difference of immune response against SARS-CoV-2 between children and adults hasn’t been reported. Therefore we initiated this study to figure out the features of immune response in children with COVID-19.Sera and whole blood cells from 19 children with COVID-19 during different phases after disease onset were collected.The cytokine concentrations, SARS-CoV-2 S-RBD or N-specific antibodies and T cell immune responses were detected respectively. In children with COVID-19, only 3 of 12 cytokines were increased in acute sera, including interferon(IFN)-cinduced protein 10(IP10), interleukin(IL)-10 and IL-16. We observed an increase in T helper(Th)-2 cells and a suppression in regulatory T cells(Treg) in patients during acute phase, but no significant response was found in the IFN-cproducing or tumor necrosis factor(TNF)-a-producing CD8?T cells in patients. S-RBD and N IgM showed an early induction, while S-RBD and N IgG were prominently induced later in convalescent phase. Potent S-RBD IgA response was observed but N IgA seemed to be inconspicuous. Children with COVID-19 displayed an immunophenotype that is less inflammatory than adults, including unremarkable cytokine elevation, moderate CD4?T cell response and inactive CD8?T cell response, but their humoral immunity against SARS-CoV-2 were as strong as adults. Our finding presented immunological characteristics of children with COVID-19 and might give some clues as to why children develop less severe disease than adults.
基金supported by the National Natural Science Foundation of China(30771968 and 91029719)
文摘The role of anti-tumor immune responses in oncolytic adenoviral therapy has not been well studied due to lack of efficacious tu- mor model in immunocompetent mice.Here,we evaluated the contributions of immune components to the therapeutic effects of oncolytic adenoviruse in an immunocompetent murine tumor model permissive for infection and replication of adenovirus.We found that CD8+T cells were critical mediator for antitumor efficacy by oncolytic adenovirus.Intratumoral viral therapy induced intensive infiltration of CD8+T cells in tumor,increased tumor-specific IFN-?(interferon-?)production and CTL(cytotoxic T lymphocyte)activity of lymphocytes,and generated a long-term tumor-specific immune memory.Boosting CD8+T cell responses by agonistic anti-4-1BB(cluster differentiation 137,CD137)antibody showed synergistic anticancer effects with oncolytic viro- therapy.Our results provide insight into antitumor mechanisms of oncolytic adenovirus in addition to their direct oncolytic effect.
基金This study was supported by the Hong Kong Research Grants Council Collaborative Research Fund(C7156-20GF to ZC and C1134-20GF)the Research Grants Council General Research Fund(GRF17117422)+5 种基金the Hong Kong Health and Medical Research Fund(COVID1903010-Project 4,COVID190123 and 19181012)the Shenzhen Science and Technology Program(JSGG20200225151410198 and JCYJ20210324131610027)HKU Development Fund and LKS Faculty of Medicine Matching Fund to AIDS Institutethe Hong Kong Innovation and Technology Fundthe Hong Kong Health@InnoHK,Innovation and Technology Commissiona generous donation from the Friends of Hope Education Fund.ZC’s team was also partly supported by the Theme-Based Research Scheme(T11-706/18-N and T11-709/21-N).
文摘Mutations in SARS-CoV-2 variants of concern(VOCs)have enhanced transmissibility and immune evasion with respect to current vaccines and neutralizing antibodies(NAbs).How naturally occurring spike mutations affect the infectivity and antigenicity of VOCs remains to be investigated.The entry efficiency of individual spike mutations was determined in vitro using pseudotyped viruses.BALB/c mice were immunized with 2-dose DNA vaccines encoding B.1.1.7,B.1.351,B.1.1.529 and their single mutations.Cellular and humoral immune responses were then compared to determine the impact of individual mutations on immunogenicity.In the B.1.1.7 lineage,Del69–70 and Del 144 in NTD,A570D and P681H in SD1 and S982A and D1118H in S2 significantly increased viral entry,whereas T716I resulted in a decrease.In the B.1.351 lineage,L18F and Del 242–244 in the NTD,K417N in the RBD and A701V in S2 also increased viral entry.S982A weakened the generation of binding antibodies.All sera showed reduced cross-neutralization activity against B.1.351,B.1.617.2(Delta)and B.1.1.529(Omicron BA.1).S982A,L18F,and Del 242–244 hindered the induction of cross-NAbs,whereas Del 69–70,Del144,R246I,and K417N showed the opposite effects.B.1.351 elicited adequate broad cross-NAbs against both B.1.351 and B.1.617.2.All immunogens tested,however,showed low neutralization against circulating B.1.1.529.In addition,T-cell responses were unlikely affected by mutations tested in the spike.We conclude that individual spike mutations influence viral infectivity and vaccine immunogenicity.Designing VOC-targeted vaccines is likely necessary to overcome immune evasion from current vaccines and neutralizing antibodies.
