The CD4 binding site(CD4bs) of envelope glycoprotein(Env) is an important conserved target for anti-human immunodeficiency virus type 1(HIV-1) neutralizing antibodies. Neutralizing monoclonal antibodies IgG1 b12(b12) ...The CD4 binding site(CD4bs) of envelope glycoprotein(Env) is an important conserved target for anti-human immunodeficiency virus type 1(HIV-1) neutralizing antibodies. Neutralizing monoclonal antibodies IgG1 b12(b12) could recognize conformational epitopes that overlap the CD4 bs of Env. Different virus strains, even derived from the same individual, showed distinct neutralization susceptibility to b12. We examined the key amino acid residues affecting b12 neutralization susceptibility using single genome amplification and pseudovirus neutralization assay. Eleven amino acid residues were identified that affect the sensitivity of Env to b12. Through site-directed mutagenesis, an amino acid substitution at position 182 in the V2 region of Env was confirmed to play a key role in regulating the b12 neutralization susceptibility. The introduction of V182 L to a resistant strain enhanced its sensitivity to b12 more than twofold. Correspondingly, the introduction of L182 V to a sensitive strain reduced its sensitivity to b12 more than tenfold. Amino acid substitution at positions 267 and 346 could both enhance the sensitivity to b12 more than twofold. However, no additive effect was observed when the three site mutageneses were introduced into the same strain, and the sensitivity was equivalent to the single V182 L mutation. CRF07_BC is a major circulating recombinant form of HIV-1 prevalent in China. Our data may provide important information for understanding the molecular mechanism regulating the neutralization susceptibility of CRF07_BC viruses to b12 and may be helpful for a vaccine design targeting the CD4 bs epitopes.展开更多
Human immunodeficiency virus type 1(HIV-1) persistence is a major barrier to the successful treatment and eradication of acquired immunodeficiency syndrome(AIDS).In addition to resting CD4+ T cells,a significant long-...Human immunodeficiency virus type 1(HIV-1) persistence is a major barrier to the successful treatment and eradication of acquired immunodeficiency syndrome(AIDS).In addition to resting CD4+ T cells,a significant long-lived compartment of HIV-1 infection in vivo includes blood monocytes and tissue macrophages.Studying HIV-1 persistence in monocyte-lineage cells is critical because these cells are important HIV-1 target cells in vivo.Monocyte-lineage cells,including monocytes,dendritic cells(DCs) and macrophages,play a significant role in HIV-1 infection and transmission.These cells have been implicated as viral reservoirs that facilitate HIV-1 latency and persistence.A better understanding of HIV-1 interactions with monocyte-lineage cells can potentially aid in the development of new approaches for intervention.This minireview highlights the latest advances in understanding the role of monocyte-lineage cells in HIV-1 persistence and emphasizes new insights into the mechanisms underlying viral persistence.展开更多
Human T lymphotropic virus type 1 (HTLV-1) is endemic in the southern part of Japan. Infection of the virus can cause adult T cell leukemia/lymphoma (ATL), while most infected individuals remain in a carrier state for...Human T lymphotropic virus type 1 (HTLV-1) is endemic in the southern part of Japan. Infection of the virus can cause adult T cell leukemia/lymphoma (ATL), while most infected individuals remain in a carrier state for a long period of time. Although rare cases of carriers, like ATL patients, who developed opportunistic infections, have been reported, hematological changes of carriers who are prone to opportunistic infections have not been well defined. Here, we present a case of an HTLV-1 carrier who developed Mycobacterium intracellulare infection and Pneumocystis jirovecii pneumonia (PcP) simultaneously. Flow cytometric analysis of bone marrow cells revealed an aberrant compositional change similar to that in ATL patients. This suggests the presence of a pre-ATL state prior to the development of ATL, which is notable in terms of underlying cellular immunodeficiency.展开更多
There are two types of Human Immunodeficiency Virus （HIV）： HIV-1 and HIV-2. HIV-1 dominates epidemics in many different parts of the world, and HIV-2 is principally responsible for the epidemic in westem Africa. In...There are two types of Human Immunodeficiency Virus （HIV）： HIV-1 and HIV-2. HIV-1 dominates epidemics in many different parts of the world, and HIV-2 is principally responsible for the epidemic in westem Africa. In China, Zeng et al have reported the first individual infected with HIV-1 in 1985. And in the 1990s, there was a severe epidemic involving the HIV-1 B＇ strain among people who sold blood and plasma in Henan, Hubei and adjacent provinces. To further study in HIV/AIDS vaccines and HIV-1 drug resistance for people in these regions, we need to construct an infectious HIV-1 B＇ molecular clone which is representative of the virus in these areas. To this end, we have isolated a HIV-1 B＇ virus from a child who was infected with HIV-1 from his mother in Hubei province, and have constructed a full-length clone from this genome.展开更多
Superinfection is frequently detected among individuals infected by human immunodeficiency virus type I （HIV-1）. Superinfection occurs at similar frequencies at acute and chronic infection stages but less frequently...Superinfection is frequently detected among individuals infected by human immunodeficiency virus type I （HIV-1）. Superinfection occurs at similar frequencies at acute and chronic infection stages but less frequently than primary infection. This observation indicates that the immune responses elicited by natural HIV-1 infection may play a role in curb of superinfection; however, these responses are not sufficiently strong to completely prevent superinfection. Thus, a successful HIV-1 vaccine likely needs to induce more potent and broader immune responses than those elicited by primary infection. On the other hand, potent and broad neutralization responses are more often detected after superinfection than during monoinfection. This suggests that broadly neutralizing antibodies are more likely induced by sequential immunization of multiple different immunogens than with only one form of envelope glycoprotein immunogens. Understanding why the protection from superinfection by immunity induced by primary infection is insufficient and if superinfection can lead to cross-reactive immune responses will be highly informative for HIV-1 vaccine design.展开更多
A new set of descriptors,namely score vectors of the zero dimension,one dimension,two dimensions and three dimensions(SZOTT),was derived from principle component analysis of a matrix of 1369 structural variables inclu...A new set of descriptors,namely score vectors of the zero dimension,one dimension,two dimensions and three dimensions(SZOTT),was derived from principle component analysis of a matrix of 1369 structural variables including 0D,1D,2D and 3D information for the 20 coded amino acids. SZOTT scales were then used in cleavage site prediction of human immunodeficiency virus type 1 protease. Linear discriminant analysis(LDA) and support vector machines(SVM) were applied to developing models to predict the cleavage sites. The results obtained by linear discriminant analysis(LDA) and support vector machines(SVM) are as follows. The Matthews correlation coefficients(MCC) by the resubstitution test,leave-one-out cross validation(LOOCV) and external validation are 0.879 and 0.911,0.849 and 0.901,0.822 and 0.846,respectively. The receiver operating characteristic(ROC) analysis showed that the SVM model possesses better simulative and predictive ability in comparison with the LDA model. Satisfactory results show that SZOTT descriptors can be further used to predict cleavage sites of human immunodeficiency virus type 1 protease.展开更多
Despite the success of antiretroviral therapy(ART),efforts to develop new classes of antiviral agents have been hampered by the emergence of drug resistance.Dibenzo-indole-bearing aristolactams are compounds that have...Despite the success of antiretroviral therapy(ART),efforts to develop new classes of antiviral agents have been hampered by the emergence of drug resistance.Dibenzo-indole-bearing aristolactams are compounds that have been isolated from various plants species and which show several clinically relevant effects,including anti-inflammatory,antiplatelet,and antimycobacterial actions.However,the effect of these compounds on human immunodeficiency virus type 1(HIV-1)infection has not yet been studied.In this study,we discovered an aristolactam derivative bearing dibenzo[cd,f]indol-4(5 H)-one that had a potent anti-HIV-1 effect.A structure-activity relationship(SAR)study using nine synthetic derivatives of aristolactam identified the differing effects of residue substitutions on the inhibition of HIV-1 infection and cell viability.Among the compounds tested,1,2,8,9-tetramethoxy-5-(2-(piperidin-1-yl)ethyl)-dibenzo[cd,f]indol-4(5 H)-one(Compound 2)exhibited the most potent activity by inhibiting HIV-1 infection with a half-maximal inhibitory concentration(IC50)of 1.03 lmol/L and a half-maximal cytotoxic concentration(CC50)of 16.91 lmol/L(selectivity index,16.45).The inhibitory effect of the compounds on HIV-1 infection was linked to inhibition of the viral replication cycle.Mode-of-action studies showed that the aristolactam derivatives did not affect reverse transcription or integration;instead,they specifically inhibited Tat-mediated viral transcription.Taken together,these findings show that several aristolactam derivatives impaired HIV-1 infection by inhibiting the activity of Tat-mediated viral transcription,and suggest that these derivatives could be antiviral drug candidates.展开更多
Background The CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccin...Background The CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccines targeting HIV-1 CRF07 BC. A highly replication-competent simian/human immunodeficiency viruses （SHIV） construct containing the Chinese CRF07_BC HIV-1 env gene with the ability to infect Chinese rhesus monkeys would serve as an important tool in the development of HIV vaccines. The aim of this study was to examine whether SHIV XJDC6431 with the env fragment from a Chinese HIV-1 isolate virus could infect the human and monkey peripheral blood mononuclear cell （PBMC）, establish infection in Chinese rhesus macaque. Methods A SHIV strain was constructed by replacing the rev/env genes of SHIV KB9 with the corresponding fragment derived from the HIV-1 CRF07_BC strain. The infectious activity of the SHIV clones was determined in vitro in PBMCs from both non-human primate animals and humans. Finally, one Chinese rhesus macaques （Macaca mulatta） was infected with one SHIV via intravenous infusion. Results One SHIV clone designated as SHIV XJDC6431, was generated that could infect macaque and human PBMC. The virus produced from this clone also efficiently infected the CCR5-expressing GHOST cell lines, indicating that it uses CCR5 as its coreceptor. Finally, the virus was intravenously inoculated into one Chinese rhesus macaque. Eventually, the animal became infected as shown by the occurrence of viremia within 3 of infection. The viral load reached 105 copies of viral RNA per ml of plasma during the acute phase of infection and lasted for 10 weeks post infection. Conclusions We conclude that SHIV XJDC6431 is an R5-tropic chimeric virus, which can establish infection not only in vitro but also in vivo in the Chinese rhesus macaque. Although the animal inoculated with SHIV XJDC6431 became infected without developing a pathologic phenotype, the virus efficiently replicated with a persistent level of viral load in the plasma. This suggested that the SHIV could be used as a tool to test candidate AIDS vaccines targeting the Chinese HIV-1 CRF 07BC recombinant strain.展开更多
The development of a vaccine based on human immunodeficiency virus type 1(HIV-1) envelope glycoprotein(Env) that elicits potent protective antibodies against infection has been challenging. Recently, we compared the a...The development of a vaccine based on human immunodeficiency virus type 1(HIV-1) envelope glycoprotein(Env) that elicits potent protective antibodies against infection has been challenging. Recently, we compared the antibody production patterns of HIV-1 Env gp120 and hepatitis B virus surface antigen(HBsAg) to provide insights into how we may improve the protective efficacy of Env-based immunogens. Our previous study showed that HIV Env and HBsAg display different mechanisms of antibody elicitation and that T cells facilitate the responses to repeated immunizations. Here, to elucidate the detailed roles of primary immunization in immune memory response formation and antibody production, we immunized C57BL/6 mice with each antigen and evaluated the development of T follicular helper(Tfh) cells, germinal centers,and the memory responses involved in prime and boost immunizations. We found that after prime immunization, compared with HBsAg, gp120 induced higher frequencies of Tfh cells and programmed death(PD)-1^+T cells, greater major histocompatibility complex II expression on B cells, comparable activated B cells, but weaker germinal center(GC)reactions and memory B cell responses in the draining lymph nodes, accompanied by slower antibody recall responses and poor immune memory responses. The above results suggested that more PD-1^+T cells arising in primary immunization may serve as major contributors to the slow antibody recall response elicited by HIV-1 Env.展开更多
基金supported by grants from National Science and Technology Major Project(2012ZX10004701)
文摘The CD4 binding site(CD4bs) of envelope glycoprotein(Env) is an important conserved target for anti-human immunodeficiency virus type 1(HIV-1) neutralizing antibodies. Neutralizing monoclonal antibodies IgG1 b12(b12) could recognize conformational epitopes that overlap the CD4 bs of Env. Different virus strains, even derived from the same individual, showed distinct neutralization susceptibility to b12. We examined the key amino acid residues affecting b12 neutralization susceptibility using single genome amplification and pseudovirus neutralization assay. Eleven amino acid residues were identified that affect the sensitivity of Env to b12. Through site-directed mutagenesis, an amino acid substitution at position 182 in the V2 region of Env was confirmed to play a key role in regulating the b12 neutralization susceptibility. The introduction of V182 L to a resistant strain enhanced its sensitivity to b12 more than twofold. Correspondingly, the introduction of L182 V to a sensitive strain reduced its sensitivity to b12 more than tenfold. Amino acid substitution at positions 267 and 346 could both enhance the sensitivity to b12 more than twofold. However, no additive effect was observed when the three site mutageneses were introduced into the same strain, and the sensitivity was equivalent to the single V182 L mutation. CRF07_BC is a major circulating recombinant form of HIV-1 prevalent in China. Our data may provide important information for understanding the molecular mechanism regulating the neutralization susceptibility of CRF07_BC viruses to b12 and may be helpful for a vaccine design targeting the CD4 bs epitopes.
基金supported in part by grants(AI068493 and AI078762)from the National Institutes of Health,USA
文摘Human immunodeficiency virus type 1(HIV-1) persistence is a major barrier to the successful treatment and eradication of acquired immunodeficiency syndrome(AIDS).In addition to resting CD4+ T cells,a significant long-lived compartment of HIV-1 infection in vivo includes blood monocytes and tissue macrophages.Studying HIV-1 persistence in monocyte-lineage cells is critical because these cells are important HIV-1 target cells in vivo.Monocyte-lineage cells,including monocytes,dendritic cells(DCs) and macrophages,play a significant role in HIV-1 infection and transmission.These cells have been implicated as viral reservoirs that facilitate HIV-1 latency and persistence.A better understanding of HIV-1 interactions with monocyte-lineage cells can potentially aid in the development of new approaches for intervention.This minireview highlights the latest advances in understanding the role of monocyte-lineage cells in HIV-1 persistence and emphasizes new insights into the mechanisms underlying viral persistence.
文摘Human T lymphotropic virus type 1 (HTLV-1) is endemic in the southern part of Japan. Infection of the virus can cause adult T cell leukemia/lymphoma (ATL), while most infected individuals remain in a carrier state for a long period of time. Although rare cases of carriers, like ATL patients, who developed opportunistic infections, have been reported, hematological changes of carriers who are prone to opportunistic infections have not been well defined. Here, we present a case of an HTLV-1 carrier who developed Mycobacterium intracellulare infection and Pneumocystis jirovecii pneumonia (PcP) simultaneously. Flow cytometric analysis of bone marrow cells revealed an aberrant compositional change similar to that in ATL patients. This suggests the presence of a pre-ATL state prior to the development of ATL, which is notable in terms of underlying cellular immunodeficiency.
基金This study was supported by the grants from the National High Technology Program 863(2005AA219070)the Project 973 of the National Program of China(2005CB522903).
文摘There are two types of Human Immunodeficiency Virus （HIV）： HIV-1 and HIV-2. HIV-1 dominates epidemics in many different parts of the world, and HIV-2 is principally responsible for the epidemic in westem Africa. In China, Zeng et al have reported the first individual infected with HIV-1 in 1985. And in the 1990s, there was a severe epidemic involving the HIV-1 B＇ strain among people who sold blood and plasma in Henan, Hubei and adjacent provinces. To further study in HIV/AIDS vaccines and HIV-1 drug resistance for people in these regions, we need to construct an infectious HIV-1 B＇ molecular clone which is representative of the virus in these areas. To this end, we have isolated a HIV-1 B＇ virus from a child who was infected with HIV-1 from his mother in Hubei province, and have constructed a full-length clone from this genome.
文摘Superinfection is frequently detected among individuals infected by human immunodeficiency virus type I （HIV-1）. Superinfection occurs at similar frequencies at acute and chronic infection stages but less frequently than primary infection. This observation indicates that the immune responses elicited by natural HIV-1 infection may play a role in curb of superinfection; however, these responses are not sufficiently strong to completely prevent superinfection. Thus, a successful HIV-1 vaccine likely needs to induce more potent and broader immune responses than those elicited by primary infection. On the other hand, potent and broad neutralization responses are more often detected after superinfection than during monoinfection. This suggests that broadly neutralizing antibodies are more likely induced by sequential immunization of multiple different immunogens than with only one form of envelope glycoprotein immunogens. Understanding why the protection from superinfection by immunity induced by primary infection is insufficient and if superinfection can lead to cross-reactive immune responses will be highly informative for HIV-1 vaccine design.
基金Supported by the Research on National High-tech R&D Program (the 863 program) (Grant No. 2006AA02Z312)Innovative Group Program for Graduates of Chong- qing University, Science and Innovation Fund (Grant No. 200711C1A0010260)
文摘A new set of descriptors,namely score vectors of the zero dimension,one dimension,two dimensions and three dimensions(SZOTT),was derived from principle component analysis of a matrix of 1369 structural variables including 0D,1D,2D and 3D information for the 20 coded amino acids. SZOTT scales were then used in cleavage site prediction of human immunodeficiency virus type 1 protease. Linear discriminant analysis(LDA) and support vector machines(SVM) were applied to developing models to predict the cleavage sites. The results obtained by linear discriminant analysis(LDA) and support vector machines(SVM) are as follows. The Matthews correlation coefficients(MCC) by the resubstitution test,leave-one-out cross validation(LOOCV) and external validation are 0.879 and 0.911,0.849 and 0.901,0.822 and 0.846,respectively. The receiver operating characteristic(ROC) analysis showed that the SVM model possesses better simulative and predictive ability in comparison with the LDA model. Satisfactory results show that SZOTT descriptors can be further used to predict cleavage sites of human immunodeficiency virus type 1 protease.
基金supported by grants from the Korea National Institute of Health (Grant Number:2019-NI-066-00 and 2020-ER5106-00)。
文摘Despite the success of antiretroviral therapy(ART),efforts to develop new classes of antiviral agents have been hampered by the emergence of drug resistance.Dibenzo-indole-bearing aristolactams are compounds that have been isolated from various plants species and which show several clinically relevant effects,including anti-inflammatory,antiplatelet,and antimycobacterial actions.However,the effect of these compounds on human immunodeficiency virus type 1(HIV-1)infection has not yet been studied.In this study,we discovered an aristolactam derivative bearing dibenzo[cd,f]indol-4(5 H)-one that had a potent anti-HIV-1 effect.A structure-activity relationship(SAR)study using nine synthetic derivatives of aristolactam identified the differing effects of residue substitutions on the inhibition of HIV-1 infection and cell viability.Among the compounds tested,1,2,8,9-tetramethoxy-5-(2-(piperidin-1-yl)ethyl)-dibenzo[cd,f]indol-4(5 H)-one(Compound 2)exhibited the most potent activity by inhibiting HIV-1 infection with a half-maximal inhibitory concentration(IC50)of 1.03 lmol/L and a half-maximal cytotoxic concentration(CC50)of 16.91 lmol/L(selectivity index,16.45).The inhibitory effect of the compounds on HIV-1 infection was linked to inhibition of the viral replication cycle.Mode-of-action studies showed that the aristolactam derivatives did not affect reverse transcription or integration;instead,they specifically inhibited Tat-mediated viral transcription.Taken together,these findings show that several aristolactam derivatives impaired HIV-1 infection by inhibiting the activity of Tat-mediated viral transcription,and suggest that these derivatives could be antiviral drug candidates.
文摘Background The CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccines targeting HIV-1 CRF07 BC. A highly replication-competent simian/human immunodeficiency viruses （SHIV） construct containing the Chinese CRF07_BC HIV-1 env gene with the ability to infect Chinese rhesus monkeys would serve as an important tool in the development of HIV vaccines. The aim of this study was to examine whether SHIV XJDC6431 with the env fragment from a Chinese HIV-1 isolate virus could infect the human and monkey peripheral blood mononuclear cell （PBMC）, establish infection in Chinese rhesus macaque. Methods A SHIV strain was constructed by replacing the rev/env genes of SHIV KB9 with the corresponding fragment derived from the HIV-1 CRF07_BC strain. The infectious activity of the SHIV clones was determined in vitro in PBMCs from both non-human primate animals and humans. Finally, one Chinese rhesus macaques （Macaca mulatta） was infected with one SHIV via intravenous infusion. Results One SHIV clone designated as SHIV XJDC6431, was generated that could infect macaque and human PBMC. The virus produced from this clone also efficiently infected the CCR5-expressing GHOST cell lines, indicating that it uses CCR5 as its coreceptor. Finally, the virus was intravenously inoculated into one Chinese rhesus macaque. Eventually, the animal became infected as shown by the occurrence of viremia within 3 of infection. The viral load reached 105 copies of viral RNA per ml of plasma during the acute phase of infection and lasted for 10 weeks post infection. Conclusions We conclude that SHIV XJDC6431 is an R5-tropic chimeric virus, which can establish infection not only in vitro but also in vivo in the Chinese rhesus macaque. Although the animal inoculated with SHIV XJDC6431 became infected without developing a pathologic phenotype, the virus efficiently replicated with a persistent level of viral load in the plasma. This suggested that the SHIV could be used as a tool to test candidate AIDS vaccines targeting the Chinese HIV-1 CRF 07BC recombinant strain.
基金supported by the Grant of National Natural Science Foundation of China (Grant number 81271824, 81772190, 81601755)the Grant of National Science and Technology Major Project (Grant number 2012ZX10001009-002003)
文摘The development of a vaccine based on human immunodeficiency virus type 1(HIV-1) envelope glycoprotein(Env) that elicits potent protective antibodies against infection has been challenging. Recently, we compared the antibody production patterns of HIV-1 Env gp120 and hepatitis B virus surface antigen(HBsAg) to provide insights into how we may improve the protective efficacy of Env-based immunogens. Our previous study showed that HIV Env and HBsAg display different mechanisms of antibody elicitation and that T cells facilitate the responses to repeated immunizations. Here, to elucidate the detailed roles of primary immunization in immune memory response formation and antibody production, we immunized C57BL/6 mice with each antigen and evaluated the development of T follicular helper(Tfh) cells, germinal centers,and the memory responses involved in prime and boost immunizations. We found that after prime immunization, compared with HBsAg, gp120 induced higher frequencies of Tfh cells and programmed death(PD)-1^+T cells, greater major histocompatibility complex II expression on B cells, comparable activated B cells, but weaker germinal center(GC)reactions and memory B cell responses in the draining lymph nodes, accompanied by slower antibody recall responses and poor immune memory responses. The above results suggested that more PD-1^+T cells arising in primary immunization may serve as major contributors to the slow antibody recall response elicited by HIV-1 Env.
