Antiviral Activity of Dual-acting Hydrocarbon-stapled Peptides against HIV-1 Predominantly Circulating in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>New rationally designed i,i+7-hydrocarbon-stapled peptides that target both HIV-1 assembly and entry have been shown to have antiviral activity against HIV-1 subtypes circulating in Europe and North America. Here, we aimed to evaluate the antiviral activity of these peptides against HIV-1 subtypes predominantly circulating in China.</p><p><b>METHODS</b>The antiviral activity of three i,i+7-hydrocarbon-stapled peptides, NYAD-36, NYAD-67, and NYAD-66, against primary HIV-1 CRF07_BC and CRF01_AE isolates was evaluated in peripheral blood mononuclear cells (PBMCs). The activity against the CRF07_BC and CRF01_AE Env-pseudotyped viruses was analyzed in TZM-bl cells.</p><p><b>RESULTS</b>We found that all the stapled peptides were effective in inhibiting infection by all the primary HIV-1 isolates tested, with 50% inhibitory concentration toward viral replication (IC50) in the low micromolar range. NYAD-36 and NYAD-67 showed better antiviral activity than NYAD-66 did. We further evaluated the sensitivity of CRF01_AE and CRF07_BC Env-pseudotyped viruses to these stapled peptides in a single-cycle virus infectivity assay. As observed with the primary isolates, the IC50s were in the low micromolar range, and NYAD-66 was less effective than NYAD-36 and NYAD-67.</p><p><b>CONCLUSION</b>Hydrocarbon-stapled peptides appear to have broad antiviral activity against the predominant HIV-1 viruses in China. This finding may provide the impetus to the rational design of peptides for future antiviral therapy.</p>

Genetic characteristics of viral quasispecies of HIV-1 CRF07_BC among intravenous drug users / 病毒学报

To explore the genetic characteristics of viral quasispecies in HIV-1 CRF07_BC infections among intravenous drug users (IDU), the gp120 fragments of HIV-1 env gene were amplified from plasma samples collected from 6 CRF07_BC infected persons using single genome amplification and sequencing (SGA/ SGS) method, and 11 to 28 sequences were obtained from these samples, respectively, A neighbor-joining phylogenetic tree was reconstructed to describe the genetic characteristics of viral quasispecies. The Simplot, segments' phylogenetic trees and diversity plots based on average pairwise distance (APD) were used to identify the recombination events between quasispecies. The SGA sequences derived from single specimen formed a large monophyletic cluster in the neighbor-joining phylogenetic tree and showed the complex topologic structures of viral quasispecies. Of the 6 CRF07_BC infected patients, only one possessed the high genetic homogeneity, whereas the other five individuals showed high heterogeneity, with two to four subclusters inside the monophyletic cluster for each specimen. In addition, the recombinant events were identified among viral quasispecies from 3 cases. The results show SGA technique and phylogenetic analyses are useful tool to investigate the intrahost CRF07_BC gp120 complex quasispecies variation and high genetic diversity.

The primary HIV drug resistance in partial region of Henan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the prevalence of primary HIV drug resistance in antiretroviral therapy (ART) areas of Henan province.</p><p><b>METHODS</b>A total of 121 drug-naive long-term infected individuals and 154 patients with newly diagnosed from January 2011 to March 2012 were recruited, the questionnaires were surveyed and whole blood were collected to analyze the CD4(+)T cell counts and viral load. In-house method for genotypic resistance test was determined in those with viral load > 1000 copies/ml samples, the differences of demographic characteristics, immunological parameters and primary drug resistance were compared between the two groups.</p><p><b>RESULTS</b>A total of 121 cases of long-term individuals who had infected (12.50 ± 3.21) years were mainly previous paid blood donors, and the age was (46.61 ± 9.32) years old. The infection route of the newly diagnosed were diversity, including blood, sexual transmission and others, the cases were 73, 73, 8, respectively, the confirmatory year was (0.91 ± 0.28) years, and average age was (22.21 ± 3.11) years old. The difference were statistically significant in the route of transmission, age and infection time from demographic analysis of the two groups (P < 0.05). The absolute M(P(25)-P(75)) counts of CD4(+)T lymphocytes of long-term group was 322 (217 - 422) cell/µl, which was lower than the newly diagnosed was 434(308 - 578) cell/µl (P < 0.05), and viral load was 4.0 (2.96 - 4.64) copies/ml, 3.77 (2.94 - 4.53) copies/ml, the difference was not significant (P > 0.05). The prevalence of primary drug resistance in long-term group and newly diagnosed was 5.79% (7/121), 9.09% (14/154), respectively, and the difference was statistically different (P < 0.05), and one PI-resistant strain was found in the newly diagnosed group.</p><p><b>CONCLUSION</b>The primary drug resistant strains in untreated patients were found in Henan province of ART areas, and there was difference in degree of resistance between long-term infected individuals and newly diagnosed.</p>

Analysis of gag-specific IFN-gamma secretion responses in HIV-1 B/C recombinant infectors / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To characterize the Gag-Specific T lymphocyte responses and identify immunodominant region recognized in Chinese HIV-1 recombinant subtype B/C infectors.</p><p><b>METHODS</b>10 antiretroviral treatment (ART) naive HIV-1 recombinant subtype B/C infectors with infected time in 1 year, 25 ART-naive infectors with infected time > 3 years and 10 HIV-1-seronegative healthy individuals were enrolled. HIV-1-specific T lymphocyte responses were analyzed by an IFN-gamma Elispot assay against 123 overlapping peptides spanning HIV-1 Gag protein in the present study.</p><p><b>RESULTS</b>Gag-specific T lymphocyte responses of interferon-gamma secretion were identified in 8(8/10) Chinese HIV-1 recombinant subtype B/ C infectors with infected time in 1 year, the specific T lymphocytes are mainly targeted at five seperated peptides. Responses were identified in 17(68%) infectors with infected time more than 3 years, the specific T lymphocytes are mainly targeted at one peptide in p17 and six in p24. There was obviously positive correlation (P = 0.0318, r = 0.519) between the magnitude of responses and viremia in infectors infected time > 3 years. The magnitude of response in infectors infected in 1 year was significantly higher than group infected time > 3 years (P = 0.021). None of healthy individuals produced positive responses.</p><p><b>CONCLUSIONS</b>HIV-1 recombinant subtype B/C Infectors at different stages of diseases recognize different region of gag.</p>

HIV-specific IL-2(+) and/or IFN-γ(+) CD8(+) T cell responses during chronic HIV-1 infection in former blood donors / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Conflicting data have been generated from previous studies to determine which kind of relationship exists between HIV-1 specific CD8 Tcell responses and HIV-1 viral load or CD4 count over the course of infection. In this study, 153 HIV-1 infected LTNPs were enrolled to investigate the role of HIV-1 specific CD8 T-cell responses in chronic HIV-1 infection among HIV-1 infected former blood donors.</p><p><b>METHODS</b>The patients were stratified into three groups according to CD4 count: CD4≥500 cells/μL; 350 cells/μL≤CD4<500 cells/μL; CD4<350 cells/μL. PBMCs were isolated from the patients' anticoagulated blood samples. IL-2 and IFN-γ secretions of CD 8 T cells against 17 HIV-1 consensus B full peptide pools were analyzed by using ICS assay.</p><p><b>RESULTS</b>An overall inverse correlation were observed between CD4 count and plasma viral load. Although no significant difference was observed during the comparisons of frequency/breadth of HIV-1 specific CD8 T cell responses, CD4 count stratification analysis showed that different correlation pattern existed in three strata: as for patients whose CD4 counts were less than 350 cells/μL, no significant correlations were identified between frequency/breadth of HIV-1 specific CD8 T cell responses and CD4 count/viral load; as for patients whose CD4 counts ranged from 350 cells/μL to 500 cells/μL, significant correlation was only observed between the response breadth of IL-2+IFN-γ+ CD8 T cells and CD4 count; however, as for patients whose CD4 counts were more than 500 cells/μL, direct correlations were identified between IL-2+IFN-γ+/IL-2+/IFN-γ+ CD8 T cells and viral load or CD4 count.</p><p><b>CONCLUSIONS</b>Universal consistent inverse correlation was only indentified between CD4 count and viral load. The relationship between HIV-1 specific CD8 T cell responses and CD4 count/viral load varied in different CD4 strata, which showed that better preserved CD4 T cells were correlated with better CD8 T cell functions.</p>

Comparison of the quantities and subset distributions of natural killer cells among different races / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Natural killer (NK) cells play critical roles in host immune defense, while the quantities and subset distributions may vary among different races. To address the difference, we compared these variables among Chinese Han, the Caucasians and the Blacks. The study may provide critical background information for both basic research and clinical investigation.</p><p><b>METHODS</b>Blood samples collected from populations of different races were tested within 12 hours after collection and subsets of NK cells were characterized using flow cytometry.</p><p><b>RESULTS</b>The absolute NK count in the Chinese Han was significantly higher than that in the Caucasian. The Han and Caucasian groups showed higher percentages of cytotoxic subset compared to that of the Black group. The percentage of cytokine-producing subset of Chinese Han group was lower than that of Caucasian and Black groups. Black group had a higher percentage of function-unknown NK subset than that of the Han and Caucasian groups.</p><p><b>CONCLUSION</b>Our data indicated that NK cell count and the distribution of different subsets varied among different races, which should be taken into consideration in related investigations.</p>

Complete human immunodeficiency virus-1 specific T lymphocyte response to Chinese human immunodeficiency virus-1 B/C chronic infectors / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To characterize the human immunodeficiency virus (HIV) -specific T lymphocyte responses and identify the immunodominant regions in Chinese HIV-1 recombinant subtype B/C chronic infectors at complete genome level.</p><p><b>METHODS</b>Twenty-five HIV-1B/C recombinant chronic infectors were screened for their specific T lymphocyte responses to a panel of peptides corresponding to the complete HIV-1 subtype B genome by gamma interferon ELISPOT assay. Kruskal-Wallis nonparametric analysis of variance was used to test significant differences across gene regions, and Tukey pairwise analysis was used to identify differences between gene regions. Spearman rank correlation was used to assess the relation between responses. Results The order of recognized frequencies of specific T lymphocyte responses to HIV proteins was Nef>Vpr>Gag>Pol>Vpu>Env>Rev>Vif>Tat. When adjusted for protein length, Nef, Vpr, Gag, and Pol were the most intensely targeted proteins and the central region of Nef, Gag p24, Pol RT, and Vpr was most frequently recognized. No significant correlation was observed between the magnitude of IFN-gamma production of HIV-l-specific T lymphocyte responses and plasma viremia, breadth of response and CD4 counts. Conclusion The central region of Nef, Gag p24, Pol RT, and Vpr is most frequently targeted in HIV-1 B/C recombinants chronic infectors. HIV-l-specific T lymphocyte responses and plasma viremia or CD4 counts play no protective role at complete genome level in these infectors.</p>

Genetic variation of gag gene in HIV-1 subtype B infections from Henan and Shanxi provinces of China / 病毒学报

The 109 whole blood samples were collected from HIV-1 infected former blood donors in Henan and Shanxi. The RNA templates were extracted from plasma and used for the full gag gene amplification and sequencing. The sequences were divided into 3 groups according to sampling year. The Entropy software was used to identify the amino acids with composition difference among different groups of amino acid sequences. The results showed that there existed 8 and 13 amino acid sites with the statistical significance difference, respectively, in sequences in year 2004 and 2005, compared to those in 2002. Among them, there existed 5 amino acid sites in two groups. Of 16 amino acid sites, the increasing polymorphism and the decreasing polymorphism along the sampling year were observed in 10 and 6 amino acid sites respectively. Of 10 sites with increased polymorphism, 8 sites were located in the CTL epitopes recognized and presented by the main HLA alleles existed in Chinese population. The 6 sites with decreasing polymorphism all existed in main domains of Gag proteins.

T cell receptor diversity of CD8+ T lymphocytes and its association with viral load in individuals with HIV-1 infection / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the complementary determining region 3 (CDR3) length diversity of T cell receptor Vbeta repertoires of CD8+ T lymphocytes and to explore its association with viral load in individuals with HIV-1 infection.</p><p><b>METHODS</b>Separation of CD8+ T cells from peripheral blood mononuclear cells (PBMCs) was carried out by using immunomagnetic beads coated with anti-CD8 antibody. Total RNAs from the purified CD8+ T lymphocytes were isolated and used to perform polymerase chain reaction (PCR) amplifications in CDR3 of 22 T cell receptor (TCR) gene families. CDR3 diversity and its association with viral load in individuals with HIV-1 infection were analyzed.</p><p><b>RESULTS</b>An average diversity for all CDR3 profiles in CD8+ T cells from 9 HIV-infected individuals was significantly different as compared to 7 age-matched healthy donors (P<0.05) with the HIV-infected individuals losing diversity in the CDR3 profiles. There was positive correlation between changes in TCR CDR3 diversity and viral load (r=0.771, P<0.05). The changes in CDR3 length diversity of Vbeta families in HIV-infected individuals, particular in Vbeta2, Vbeta4, Vbeta5, Vbeta17, Vbeta20, Vbeta21, Vbeta23, Vbeta24, were statistically different from the healthy controls.</p><p><b>CONCLUSION</b>HIV-1 infection might induce the loss of TCR Vbeta repertoire diversity and disrupt the CDR3 distributions within CD8+ T cells. There should be positive correlation between changes in TCR CDR3 diversity and the viral load in HIV-1 infected patients.</p>

CTL responses to regulatory proteins Tat and Rev in HIV-1 B'/C virus-infected individuals / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To characterize HIV-1 specific CTL responses to regulatory proteins Tat and Rev in HIV-B'/C virus-infected ART-naive individuals.</p><p><b>METHODS</b>HIV-1-specific CTL responses were analyzed by IFN-gamma ELISPOT assay using overlapping peptides spanning the consensus sequences of HIV-1 clade C Tat and Rev proteins. Statistical analysis and graphical presentation were performed using SIGMAPLOT 10.0 and SIGMASTAT 3.5. For samples with a positive response, the magnitude of CTL responses was compared between HIV-1 C proteins by Wilcoxon rank sum test, and the significance threshold was P<0.05.</p><p><b>RESULTS</b>Tat and Rev were frequently recognized, with 23% and 52% of the tested individuals having detectable responses to these proteins, respectively. Several immunodominant regions were detected in Rev. No significant correlation was observed between the magnitude and breadth of CTL responses to regulatory proteins and the control of virus replication in this study.</p><p><b>CONCLUSION</b>Tat and Rev can serve as targets for HIV-1-specific CTL, and several immunodominant regions are detectable in Rev. Further characterization of epitopes and their role in virus control may shed light on pathogenesis of HIV-1 natural infection and also be useful for the design and testing of candidate vaccines.</p>

Relationship of HLA-A, -Cw Polymorphisms with HIV/AIDS in Chinese Yi Ethnic Group of Sichuan Province / 中国病毒学

The relationship of HLA-A, -Cw alleles on HIV infection and AIDS disease progression in the Chinese Yi ethnic group of Sichuan province were investigated. The genetic polymorphisms of HLA-A, -Cw alleles of 102 unrelated healthy Chinese Yi ethnic individuals, 68 HIV-1 infected and 21 HIV positive long-time survivors were typed by PCR-SSP assay. Statistic signifiance was determined by the χ2 test with the SPSS software. No significant differences were observed between the HLA-A, -Cw alleles of the 68 HIV-1 infected and 102 non-infected Chinese Yi control individuals. Whereas the prevalence of A*3601,Cw*14(01-03)and Cw*0304 was significantly higher in 21 long time survivors compared with 102 healthy controls with P values of 0.016, 0.016 and 0.000 by χ2 or the Fisher exact test respectively. The result implies that A*3601,Cw*14(01-03) and Cw*0304 may be associated with slow AIDS disease progression in the Chinese Yi ethnic group, further studies on this association may yield insight on the pathogenesis of HIV-1 infection.

Enhancement of DNA vaccine-induced immune responses by a 72-bp element from SV40 enhancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although DNA vaccine is considered as the next generation of vaccine, most DNA vaccine candidates are still suffering from the relatively weak immunogenicity despite the increased dosage of plasmid DNA administered. In order to enhance the immune responses elicited by a codon-optimized HIV gag DNA vaccine, a modified plasmid vector pDRVI1.0 and a booster immunization with replicating Tiantan vaccinia (RTV) strain expressing the same gene were employed.</p><p><b>METHODS</b>Vector pDRVI1.0 was constructed through inserting the 72-bp element from the SV40 enhancer, which was reported promoting nuclear transport of plasmid DNA, to the upstream of cytomegalovirus enhancer/promoter region of the plasmid vector pVR1012. Gene expression levels from expression plasmids based on pDRVI1.0 and pVR1012 were tested. Humoral and cellular immune responses induced by DNA vaccine alone or DNA prime-RTV boost regimen were determined in mice.</p><p><b>RESULTS</b>It was shown that the 72-bp element significantly enhanced the gene expression level in non-dividing cells. gag-specific humoral and cellular immune responses induced by DNA vaccination were both significantly improved, while the Th1/Th2 balance was not obviously affected by the 72-bp element. RTV boosting further significantly enhanced DNA vaccine-primed antibody and T cell responses in a Th1-biased manner.</p><p><b>CONCLUSIONS</b>The 72-bp SV40 enhancer element should be included in the DNA vaccine vector and RTV strain is a very efficient live vector for boosting immunization.</p>

Epidemiology, clinical and laboratory characteristics of currently alive HIV-1 infected former blood donors naive to antiretroviral therapy in Anhui Province, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Unregulated commercial blood/plasma collection among farmers occurred between 1992 and 1995 in central China and caused the second major epidemic of human immunodeficiency virus type 1 (HIV-1) infection in China. It is important to characterize HIV-1-infected former blood donors and to study characteristics associated with disease progression for future clinical intervention and vaccine development.</p><p><b>METHODS</b>A cross-sectional study was performed on HIV-1-infected former blood donors (FBDs) and age-matched HIV-seronegative local residents. Demographic, epidemiologic, clinical and key laboratory data were collected from all study participants. Both unadjusted and adjusted multivariate linear regressions were employed to analyze the association of the decrease of CD4(+) T-cell counts with other characteristics.</p><p><b>RESULTS</b>Two hundred and ninety-four HIV-1-infected FBDs and 59 age-matched HIV-seronegative local residents were enrolled in this study. The unregulated blood/plasma collection occurred more than a decade (10.8 - 12.8 years) ago, which caused the rapid spread of HIV-1 infection and the high prevalence of co-infection with hepatitis C virus (HCV, 89.5%); hepatitis B virus (HBV) co-infection was observed in only 11 HIV(+)participants (3.7%). Deterioration in both clinical manifestation and laboratory parameters and increase of viral loads were observed in parallel with the decrease of CD4(+) T-cell counts. The decrease of total lymphocyte counts (P < 0.001) and hemoglobin levels (P < 0.001) and the appearance of dermatosis (P = 0.03) were observed in parallel with the decrease of CD4(+) T-cell counts whereas viral loads (P < 0.001) and CD8(+) T-cell counts (P = 0.01) were inversely associated with CD4(+) T-cell counts.</p><p><b>CONCLUSIONS</b>Co-infection with HCV but not HBV is highly prevalent among HIV-1-infected FBDs. CD4(+) T-cell counts is a reliable indicator for disease progression among FBDs. Total lymphocyte counts, hemoglobin level and appearance of dermatosis were positively associated with CD8(+) T-cell counts and viral loads were inversely associated with the decreased CD4(+) T-cell counts.</p>

Identification of HIV-1 specific T lymphocyte responses in highly exposed persistently seronegative Chinese / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Studies of highly exposed persistently seronegative (HEPS) individuals may provide valuable information on mechanisms of protection and on vaccine design. Cellular immune responses play a critical role in containing human immunodeficiency virus. However, the cellular immune responses in HEPS individuals have not been thoroughly assessed at the entire viral genome level.</p><p><b>METHODS</b>Ten HEPS Chinese with a history of frequent penetrative vaginal intercourse (mean frequency, at least once a week), with some unprotected sexual contact occurring in the weeks or days immediately before enrollment, 25 HIV-1 seropositive individuals, 10 HIV-1-seronegative healthy individuals with low-risk sexual behavior and no history suggestive of exposure to HIV-1 infection were enrolled. HIV-1-specific T cell responses were comprehensively analyzed by an interferon-gamma Elispot assay against 770 overlapping peptides spanning all HIV-1 proteins.</p><p><b>RESULTS</b>HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 3 (30%) out of 10 HEPS individuals; the specific cytotoxic T lymphocytes were targeted at Pol (2/10), Env (2/10), and Tat (1/10). HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 20 (80%) out of 25 seropositive intravenous drug users (IDUs), revealing that all HIV-1 proteins and protein subunits could serve as targets for HIV-1-specific CD8(+) T cell responses with 85% recognizing Gag, 80% recognizing Nef, 75% recognizing Pol, 60% recognizing Env, 55% recognizing Vpu, 45% recognizing Vpr, 20% recognizing Vif, 20% recognizing Tat and 15% recognizing Rev in these seropositive individuals. None of the seronegative healthy individuals gave the positive T-cell responses.</p><p><b>CONCLUSIONS</b>About 30% of HEPS Chinese mounted HIV-1 specific T cell immune responses. Cell-mediated immunity against HIV-1 may be developed through non-productive infections.</p>

HLA-B Alleles Associated with Susceptibility or Resistance to Human Immunodeficiency Virus Type 1 in a Xinjiang Uygur Population, China / 中国病毒学

Host genetic factors, such as human leukocyte antigen (HLA) alleles, are important in Human immunod-eficiency virus (HIV) infection and its progression to AIDS. HLA class I genes, especially highly polymorphicHLA-B genes, are involved in the activation of HLA-restricted cytotoxic T lymphocytes (CTLs) against HIV, andthus control susceptibility to or protect against this virus. The present study was aimed to determine the distributionof HLA-B alleles in the Chinese Uygur ethnic group and its association with HIV infection. One hundred ten healthycontrol (HIV negative) and 128 HIV positive Chinese Xinjiang Uygur ethnic individuals were used in this study.HLA typing for B allele was performed by polymerase chain reaction (PCR) with sequence-specific primers (SSP).Hardy-Weinberg equilibrium was calculated using POPGENE software for the healthy control group. The HLA-Bfrequency of each allele was compared between the patients and the controls using the chi-square test. In HIV-1-pos-itive group, gene frequency of allele B * 4901 was significantly higher compared to the healthy control subjects (P=0.02, OR=3.06, 95%CI=1.16～8.10 forB*4901). In contrast, the gene frequency of B * 40 in healthy controlswas significantly higher than in the HIV-positive patients (P=0.02, OR=0.39, 95%CI=0.07～0. 92 for B* 40).In this study, HLA allele B * 4901 may be associated with increased susceptibility to HIV-1 infection, whereas the B* 40 allele may be associated with resistance to H HIV-1 infection.

Association of neutralization sensitivity of HIV-1 primary isolates with biological properties of isolates from HIV-1 infected Chinese individuals / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Although HIV-1 infection is prevalent in many regions in China, it remains largely unknown on the biological characteristics of dominant circulating isolates. This study was designed to isolate the circulating viral strains from different prevalent regions and to characterize their biological properties and neutralization sensitivity.</p><p><b>METHODS</b>Primary viruses were isolated from fresh PBMCs using the traditional co-culture method and their capacity of inducing syncytium was tested in MT-2 cells. Meanwhile, their coreceptor usage was determined with two cell lines: Magi and GHOST (3) stably expressing CD4 and the chemokine receptor CCR5 or CXCR4. Furthermore, the sensitivity of these viruses to neutralization by HIV-1-infected patients' plasma which were highly active to neutralize SF33 strain, was quantified in GHOST cell-based neutralization assay.</p><p><b>RESULTS</b>Six primary viral strains were isolated from 4 separated regions. Isolates LTG0213, LTG0214 and XVS032691 induced syncytia in MT-2 cells, and used CXCR4 as coreceptor. Isolates XJN0021, XJN0091, or SHXDC0041 did not induce syncytia, and used CCR5 as coreceptor. Overall neutralization sensitivity differed among four representative strains: HIV-1 XVS032691 > LTG0214 >XJN0091 approximately SHXDC0041.</p><p><b>CONCLUSION</b>The neutralization sensitivity of HIV isolates is linked with the phenotype of isolates, in which syncytium-inducing (SI) or CXCR4-tropic (X4) viruses are more easily neutralized than non-syncytium-inducing (NSI) or CCR5-tropic (R5) viruses. The genetic subtypes based on the phylogeny of env sequences are not classical neutralization serotypes.</p>

Association of HLA-B alleles with human immunodeficiency virus type 1 infection in the Yi ethnic group in Sichuan province / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine the distribution of HLA-B alleles in the Chinese Yi ethnic group and its association with HIV infection.</p><p><b>METHODS</b>One hundred and six unrelated healthy HIV negative and 73 HIV positive Chinese Yi ethnic individuals were typed by PCR-SSP.</p><p><b>RESULTS</b>The frequency of alleles B*07, Bx 35, and B*46 were increased in HIV-1-positive subjects, whereas the alleles B*55, B*44 and B*78 were absent in the HIV-infected persons studied. The B*46 allele was present in a significantly higher gene frequency among HIV-1-positive individuals (P=0.02, OR=3.32, 95% CI=1.13-9.78) compared with control subjects.</p><p><b>CONCLUSION</b>HLA-B*46 may be associated with its susceptibility to HIV-1 infections.</p>

Distribution of recombinant human immunodeficiency virus type-1 CRF01_AE strains in China and its sequence variations in the env V3-C3 region / 中华预防医学杂志

<p><b>OBJECTIVE</b>To characterize CRF01_AE strains of recombinant human immunodeficiency virus type-1 (HIV-1) found in the Second National Molecular Epidemiology Study on HIV in China and to analyze its sequence variation in the env V3-C3 region during the First National Molecular Epidemiology Study (NMES1, 1996 - 1998) to the Second National Molecular Epidemiology Study (NMES2, 2001 - 2002).</p><p><b>METHODS</b>DNA was extracted from peripheal blood mononuclear cells of the subjects with HIV infection. The env C2-V4 region of HIV-1 was amplified with nested polymerase chain reaction (n-PCR). PCR products were directly sequenced using ABI 377 DNA sequencer, then the gene-based phylogenetic tree was constructed and its variation of amino acids was analyzed with GCG software.</p><p><b>RESULTS</b>Totally, 169 strains of recombinant HIV-1 CRF01_AE were identified from blood samples collected from different high risk groups in 17 of 31 provinces, municipalities and autonomous regions all over China by the end of 2002. Although sexual transmission still dominated during NMES1 (62.2%, 23/37) and NMES2 (55.3%, 73/132), prevalence of HIV-1 CRF01_AE in intravenous drug users (IDUs) increased to 41.6% (57/137) during NMES2 from 27% (10/37) during NMES1. Phylogenetic tree analysis showed that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 did not cluster with those prevalent in the subjects infected by sexual transmission during NMES2 and those in IDUs during NMES1. The amino acid residues of V3 region of HIV-1 CRF01_AE in IDUs were relatively conservative, but the sixth, eighth, ninth, tenth, twelfth, fifteenth, sixteenth amino acid residues of C3 region displayed regular changes.</p><p><b>CONCLUSIONS</b>HIV-1 CRF01_AE strain has been introduced into inland provinces from southeastern coast areas and southwestern border areas, with an increasing prevalence in IDUs. The sequence of env V3-C3 region of recombinant HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 was obviously different from that during NMES1, suggesting that HIV-1 CRF01_AE strains prevalent in IDUs during NMES2 might come from a new source and have a potential to spread.</p>

The construction of attenuated Tiantan recombinant vaccinia virus vector with IFN-gamma receptor gene deletion / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>B8R gene encodes a secreted protein with homology to IFN-gamma receptor, which neutralizes the antiviral and immunological regulation activities of IFN-gamma. To improve the safety of vaccinia virus vector, an attenuated recombinant vaccinia virus with the B8R gene deletion from Tiantan vaccine strain (VTT) was constructed.</p><p><b>METHODS</b>The transfer vectors were generated by joining B8R left flank, B8R right flank, vv promoter, LacZ, multicloning site and pBRSK fragments. The recombinant viruses VTTdeltaB8RLacZ (VTT with B8R deletion and LacZ insertion) were constructed by homologous recombination.</p><p><b>RESULTS</b>The B8R deletion mutants were confirmed by dot blot with B8R gene probe and PCR amplification. The replication ability of VTTdeltaB8RLacZ strain in vitro was similar to that of the VTT. The skin lesions formed by VTTdeltaB8RLacZ (10(6) pfu) were significantly smaller and healed faster than those formed by VTT when injected intradermally to the rabbits,and no visible ulceration occurred. Meanwhile LacZ in VTKgpedeltaB8RLacZ was expressed stably.</p><p><b>CONCLUSIONS</b>The attenuated vector with B8R gene deletion improves the safety of recombinant vaccinia virus vaccine B8R locus may be used as a new site for insertion of foreign genes in vaccinia virus vector.</p>

Development of a subtype screening assay for human immunodeficiency virus type 1 by nested multiplex PCR / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>The current available assays for HIV subtyping, such as sequence-based phylogenetic analysis or heteroduplex mobility assay (HMA), are labor-intensive and time-consuming. The authors have just developed a simple and rapid subtype-screening assay for subtypes B, C, and CRF01-AE using a single nested multiplex PCR.</p><p><b>METHODS</b>Proviral DNA from HIV-positive samples was extracted and subjected to first round PCR with universal primers for gag region that can detect HIV-1 M group isolates. In the second round PCR, three pairs of subtype-specific primers, respectively detecting subtype B, C and CRF01-AE, were added into one tube. The PCR products of different subtypes could be distinguished in agarose-gel electrophoresis. Another pair of primers exclusively detecting the prevalent recombinant B/C strains CRF07-BC and CRF08-BC were designed and used. Additionally, all of these samples were sequenced and analyzed phylogenetically.</p><p><b>RESULTS</b>Phylogenetic analysis showed that out of 119 samples, there were 43 subtype B samples (Euro-American B 11, Thailand B 32), 54 subtype C, 17 CRF01-AE, 3 subtype A and 2 subtype D samples. The subtype B, C, and CRF01-AE specific primer sets detected 35 (81.4%), 46 (85.2%), and 13(76.5%) samples with accuracy and specificity. Non-specific bands occasionally appeared but did not interfere with interpretation of the results. The primer pairs for CRF07-BC and CRF08-BC amplified target sequences were confirmed by sequencing and phylogenetic analysis. The specificity of all these subtype-specific primers was found to be 100%.</p><p><b>CONCLUSION</b>A simple and rapid assay was developed for screening subtypes B, C, CRF01-AE, CRF07-BC and CRF08-BC in China. This assay may have potential application in HIV laboratories in China and worldwide.</p>