摘要:

ObjectiveA lack of productive HIV-1 infection of Kit225 compared to Jurkat T cells, despite similar levels of CD4 and HIV-1 chemokine co-receptors, was found to correlate with the expression of vasoactive intestinal peptide/pituitary adenylate cyclase activating polypeptide receptor-1 (VPAC1). We therefore examined a role for this seven-transmembrane G protein-coupled neuroendocrine receptor in modulating HIV-1 infection.MethodsReverse transcription–PCR was used to show the level of VPAC1 expression in different T-cell lines. A signal-blocking antibody to VPAC1 was used to examine its inhibiting effect on HIV-1 infection. Transfection of VPAC1 cDNA in both sense and anti-sense orientation was used to assess the role of VPAC1 in HIV-1 infection. HIV-1 infection was monitored bygagp24 ELISA using HIV-1IIIBor by luciferase activity using pseudo envelope-typed HXB2-NL4-3-luciferase. Analysis of HIV-1gagDNA and 2-LTR circles was utilized to examine a possible mechanism for the effect of VPAC1.ResultsUsing VPAC1 signal blocking antibody, we showed that up to 80% of productive infection with HIV-1IIIBwas inhibited. We also demonstrated that HIV-1 gp120 has sequence similarity to the natural ligand for VPAC1 and postulate that it can activate this receptor directly. Transfection of VPAC1 cDNA in the anti-sense orientation resulted in a significant loss, up to 50% of productive infection. In contrast, transfection of cells with VPAC1 in the sense orientation increased the productive infection by more than 15-fold and caused a profound increase in syncytium formation. Furthermore, stimulation of VPAC1 on primary cells facilitatedin vitroinfection with HIV-1 HXB2-NL4-3. Analysis of HIV-1gagDNA indicated that VPAC1 does not affect viral entry; however, cells that show negligible expression of VPAC1 may not be productively infected as indicated by a lack of 2-LTR circle formation.ConclusionWe have discovered a cellular receptor, VPAC1, that is a novel and potent facilitator of HIV-1 infection and thus, is a potentially important new target for therapeutic intervention.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesHIV-1 p15 Gag and its protease cleavage products, NCp7 and p6, are believed to play a major role in viral infectivity and assembly during the early and late stages of the retroviral life cycle. However, the extent to which p15 Gag is targeted by the host immune system in natural infection as well as precise cytotoxic T lymphocyte (CTL) epitopes within this protein remains to be defined.MethodsIn this study, 57 HIV-1 infected individuals and 10 HIV-1 negative controls were screened for CD8 and CD4 T-cell responses using overlapping peptides spanning the entire p15 Gag protein as well as the p17 Gag and p24 Gag proteins. Peptide-specific interferon-γ production was measured by Elispot assay and flow-based intracellular cytokine quantification, and cytotoxic activity was confirmed after isolation of peptide-specific CD8 T-cell lines.ResultsCD8 T lymphocytes specific to p15 Gag were found in 46% (26/57) of HIV-1 infected individuals studied and contributed on average 17% (range, 0–100%) to the total Gag-specific T-cell responses. Responses were clustered within three immunodominant regions of p15 Gag, mapping to important functional sites. These studies also include the description of the first three optimally defined CTL epitopes within p15 Gag.ConclusionsThese results indicate that p15 Gag is frequently recognized by HIV-1-specific CD8 T cells in HIV-1 infection and will be important in the comprehensive assessments of CTL responses in infected persons, as well as the design and testing of future HIV-1 vaccines and immunotherapeutic interventions.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundIncreased and premature T cell apoptosis is recognized as a feature of HIV infection, and its normalization during highly active antiretroviral therapy (HAART) is thought to contribute to quantitative CD4 T cell restoration.DesignCross-sectional study of spontaneous, CD3- and CD95-mediated apoptosis in lymphocytes from 53 HIV-infected individuals taking HAART.MethodsOvernight stimulation of peripheral blood mononuclear cells (PBMC) with coated anti-CD3 or anti-CD95 monoclonal antibodies or incubation overnight in medium. Apoptosis in CD4 and CD8 T cells was measured by flow cytometry. Forin vitroassay of antiretroviral drugs, normal PBMC were prestimulated with anti-CD3 monoclonal antibodies and apoptosis was induced by ligation of CD95. The expression of active caspase-8 and caspase-3 was examined by flow cytometry.ResultsWe report for the first time that important levels of T cell apoptosis may persist under HAART, in spite of a rise in CD4 T cells from baseline and a sustained suppression of plasmatic viral load. Spontaneous CD3- or CD95-induced apoptosis levels were inversely correlated with thein vivonumber of CD4 T cells and the CD4/CD8 ratio, but not with the viral load or duration of antiretroviral therapy. Regimens including lamivudine are associated with persistent T cell apoptosis, particularly following CD95 ligation. Lamivudine was also found to stimulatein vitroCD95-induced apoptosis and caspase activation in pre-activated T lymphocytes from healthy donors.ConclusionThe immunomodulatory effect of lamivudine may be one of the contributing factor to increased levels of T cell apoptosis under HAART. The data suggest that there is a requirement for physiological apoptosis during HAART.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveThe recovery of CD4 target cells following antiretroviral therapy may facilitate virus production and escape from antiretroviral suppression. To address this hypothesis, we directly examined whether the CD4 target cell number increases viral production in the presence of suboptimal therapy.DesignThe effect of the CD4 T cell number on HIV-1 replication with a suboptimal dose of zidovudine was studiedin vitro.MethodsVarying numbers of CD4 T cells were infected with HIV-1 and treated with 1 nM zidovudine. Virus production was measured by p24 antigen capture enzyme-linked immunosorbent assay. Partial sequencing of HIV-1polwas performed to assess zidovudine-resistant mutations.ResultsWild type virus production was found to increase eightfold in cultures with 100 × 104cells compared with cultures with 10 × 104cells. The IC90of zidovudine was 4 logs higher in cultures with 16 × 104cells compared with cultures with 1 × 104cells. No zidovudine-resistant mutations were found.ConclusionTarget cell availability may play a direct role in wild type HIV-1 resurgence following therapy.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo study the expression of HLA-G on peripheral blood mononuclear cells (PBMC) from HIV-1-infected individuals in order to determine whether this molecule is induced as a consequence of HIV-1 infection.DesignA total of 23 HIV-positive individuals in different stages of the disease were studied.MethodsFlow cytometric analysis and Western blot were used to measure HLA-G expression on PBMC obtained from HIV-positive and control individuals.ResultsMost of the monocytes obtained from HIV-1-infected individuals express HLA-G, whereas only a very low proportion of monocytes from healthy individuals express this molecule. When T lymphocytes from HIV-1 infections were studied, it was found that 30% of them express HLA-G, whereas only 1% were HLA-G-positive in healthy individuals. HLA-G expression was also confirmed by Western blot using specific anti-HLA-G monoclonal antibodies.ConclusionThe synthesis of HLA-G is increased in monocytes and certain T lymphocytes from HIV-1-infected individuals.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundThe molecular basis of lipodystrophy, a syndrome associated with HIV antiretroviral (ARV) therapy, remains unknown.ObjectivesTo examine whether ARV therapy might inhibit the expression of CD36, which is known to play an important role in fatty acid and glucose metabolism, and if this might contribute to the metabolic alterations associated with lipodystrophy.DesignThe effects of ARV therapy on CD36 levels was examinedin vivoin a prospective cohort of individuals treated with ARV therapy andin vitroin assays of human cell lines exposed to ARV drugs.MethodsMonocyte CD36 levels were assessed by flow cytometry at baseline and after 7 days of therapy in five healthy volunteers and 10 treatment-naive HIV-1-infected individuals. ARV therapy included protease inhibitors (ritonavir, nelfinavir or lopinavir/ritonavir). In addition, human cell lines (THP-1 and C32) were assessed for CD36 levels pre and post-ritonavir treatment.ResultsThree of four healthy controls (one withdrew because of adverse effects) and 6 of 10 HIV-1-infected individuals had a 50 to > 90% decrease in monocyte CD36 levels after 7 days of therapy. One of ten HIV-infected subjects had a 30% decrease, and the remaining individuals had no change or an increase in CD36 levels. CD36 levels decreased significantly in human cell lines treated with ritonavir but not in those treated with zidovudine.ConclusionsARV therapy resulted in a marked decrease in CD36 in approximately 70% of our participants. Sustained ARV therapy-induced CD36 deficiency may contribute to insulin resistance and other metabolic complications of lipodystrophy.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo study the long-term immunological recovery in HIV-1-infected individuals receiving potent antiretroviral therapy (ART).DesignProspective, observational study.MethodsPlasma HIV-1 RNA, CD4 and CD8 T lymphocyte counts were determined at 3–6 monthly intervals in 95 HIV-1-infected subjects receiving ART who suppressed plasma HIV-1 RNA to levels below 400 copies/ml during a median observation period of 45 months.ResultsThe median CD4 cell count rose from 325 to 624 cells/μl at 48 months, increasing by 22.6 cells/μl per month in the first 3 months, 8.1 cells/μl per month from months 3 to 12, 6.8 cells/μl per month in the second year, 3.3 cells/μl per month in the third, and 1.7 cells/μl per month in the fourth year. At 48 months, 98% of subjects reached CD4 cell counts > 200 cells/μl, 86% > 350 cells/μl, and 74% > 500 cells/μl. A higher nadir CD4 cell count and younger age were independently associated with greater increases in CD4 cell counts, and higher absolute CD4 cell counts at 48 months. Poor immunological responders who did not reach 500 CD4 lymphocytes/μl at 48 months showed lower nadir and baseline CD4 cell counts than good responders (99 versus 300 cells/μl and 160 versus 373 cells/μl, respectively).ConclusionThe recovery of CD4 T lymphocytes occurs mainly in the first 2 years after the initiation of ART, and is associated with age and the pre-existing degree of HIV-1-related immunodeficiency, suggesting that the long-term exposure to HIV-1 infection has caused damage to the immune system that is difficult to correct.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo establish the influence of genotypic resistance-guided treatment decisions and patient-reported adherence on the virological and immunological responses in patients failing a potent antiretroviral regimen in a randomized, controlled trial in a tertiary care infectious diseases department.PatientsA total of 174 patients with virological failure were randomly assigned to receive standard of care (SOC) or additional genotypic resistance information (G). Adherence was measured by a self-administered questionnaire.Main outcomes measuresPrimary endpoints were the proportion with HIV-RNA < 500 copies/ml at 3 and 6 months by intention-to-treat analysis. Secondary endpoints were changes from baseline HIV-RNA levels and CD4 cell counts.ResultsAt entry, 25% had failed three or more highly active antiretroviral therapy (HAART) regimens and 41% three drug classes; there were more resistance mutations in G. In 127 evaluable questionnaires, 43% reported last missed dose during the previous week. At 3 months, 11 of 89 patients (12%) in SOC and 23 of 85 (27%) in G had HIV-RNA < 500 copies/ml (OR 2.63, 95% CI 1.12–6.26); the relative proportions were 17 and 21% at 6 months. CD4 cell changes did not differ between arms. Six month CD4 cell changes were +62 in adherent and −13 cells/μl in non-adherent patients (P< 0.01). Being assigned to G, good adherence, previous history of virological success, fewer experienced HAART regimens and lower baseline viral load were independently predictive of 3 month virological success.ConclusionThe virological benefit of genotype-guided treatment decisions in heavily pre-exposed patients was short term. Patients adherence and residual treatment options influenced outcomes.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesMany patients have simplified their therapy by replacing protease inhibitors (PI) with efavirenz. In a large cohort study representative of clinical practice, we compared outcomes in patients who replaced PI with efavirenz (switchers), with patients who continued on PI (non-switchers). We investigated the likelihood of virological failure in switchers and non-switchers, and the tolerance of efavirenz-containing regimens in different transmission risk groups.Design, setting, and methodsUsing the database of the Swiss HIV Cohort Study, we identified patients who switched from PI-containing to efavirenz-containing highly active antiretroviral therapy for reasons of tolerance, toxicity, or convenience. Switchers were matched to non-switchers on the basis of calendar time, CD4 cell count, and viral load.ResultsThe probability of virological failure was less in patients who switched to efavirenz values after one year: 9.4% [95% confidence interval (CI) 5.5–15.9] versus 27.2% (95% CI 21.5–34.1), odds ratio (OR) for failure 0.34. The effect was more pronounced when injection drug users (IDU) were omitted from the analysis (OR 0.19, 95% CI 0.09–0.43); it was absent in IDU (OR 0.95, 95% CI 0.44–2.04). IDU stopped efavirenz more frequently during the first 2 months of treatment than non-IDU [22.6% (95% CI 11.5–41.6) versus 6.6% (95% CI 3.6–11.8) at 2 months]. No difference between IDU and non-IDU was evident when the frequency of stopping indinavir or nelfinavir was measured.ConclusionSwitchers had less virological failure and less chance of further treatment changes than non-switchers. However, efavirenz was less successful in IDU than in other transmission categories.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo assess the safety and efficacy of three new drugs in patients with antiretroviral failure and to correlate retrospectively baseline factors with virological response.Design and settingOpen-label, 48-week, single-arm, multi-center phase II trial conducted at nine US university or government clinics and private practices.Patients and interventionsPatients with HIV-1 RNA ⩾ 500 copies/ml despite ⩾ 20 weeks of treatment with at least one protease inhibitor received abacavir 300 mg twice a day, amprenavir 1200 mg twice a day and efavirenz 600 mg once a day. Other antiretrovirals were prohibited until week 16 except for substitutions for possible abacavir hypersensitivity.Main outcome measuresHIV RNA at weeks 16 and 48.ResultsA total of 101 highly treatment-experienced patients enrolled; 60 were naive to non-nucleoside analog reverse transcriptase inhibitors (NNRTI). HIV RNA < 400 copies/ml was attained in 25 out of 101 (25%) patients at 16 weeks (35% of NNRTI-naive and 10% of -experienced patients) and 23 (23%) patients at 48 weeks (33% of naive and 7% of experienced patients). CD4 cells increased by a median of 15 × 106and 43 × 106cells/l at weeks 16 and 48, respectively. Drug-related rash occurred in 50 out of 99 (51%) of patients, and 17 out of 99 (17%) permanently discontinued one or more drugs as a result. Lower baseline viral load, fewer NNRTI-related mutations, absence of decreased abacavir (⩾ 4-fold) and efavirenz (⩾ 10-fold) susceptibility, and greater number of drugs to which virus was susceptible were associated with virological response at week 16.ConclusionsAbacavir, amprenavir and efavirenz durably reduced HIV RNA and increased CD4 cell counts in a subset of treatment-experienced adults. Baseline viral load and some genotypic and phenotypic markers of resistance correlated with HIV RNA response.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID