ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundSubstantial redistribution of lymphocytes occurs upon the initiation of highly active antiretroviral therapy (HAART) and immune-based HIV therapies.ObjectiveTo evaluate the relative contribution of apoptosis and proliferation to changes in lymphocyte populations in peripheral blood and lymph node resulting from interleukin-2 (IL-2) therapy in patients receiving stable HAART.MethodsLymphocyte apoptosis was analyzed on various subtypes using fluorescence activated cell sorting with an annexin-V antibody in peripheral blood and by the TUNEL (terminal uridine nucleotide end labelling) method in corresponding lymph node sections. Lymphocyte proliferation was evaluated using an antibody against the cell cycle-associated marker Ki-67 (MIB-1) in peripheral blood and lymph nodes.ResultsA transient increase in apoptosis was seen in peripheral blood and lymph nodes during a cycle of subcutaneous IL-2. A pronounced proliferative effect of IL-2 (from 6.4% of total lymphocytes in patients only treated with HAART to 23.4% in those treated with HAART + IL-2) was detected in peripheral blood, affecting the CD4, CD8 and CD16/56 subsets to a similar extent. Remarkably, the proliferative effect also occurred in lymphoid tissues. While the lymph node structure gradually disintegrated over 24 months in some individuals, the amount of proliferating lymphocytes, including CD4 cells, B cells and follicular dendritic cells, greatly increased upon IL-2, while HIV RNA load in lymph nodes remained unaffected.ConclusionThese results show that IL-2 leads to lymphocyte proliferation in peripheral blood and lymph nodes without an impact on viral load in lymphoid tissue. These results have important implications for attempts to reconstitute the immune system in HIV disease.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

DesignAntiretroviral therapy (ART) currently represents the best way to avert the lethal consequences of chronic persistent HIV-1 infection. It leads to significant reductions of plasma viremia, often to undetectable levels, but it can also be linked with the reduction and disappearance of detectable HIV-specific CD8 T-cell responses.ResultsHere we describe a group of patients in whom ongoing replication of HIV, particularly transcription of Nef mRNA species, was detected despite prolonged and clinically successful antiretroviral treatment. Modest, but significant, numbers of HIV-specific CD8 T cells and CD4 T-cell responses were found in these subjects, with the strongest responses directed towards Nef epitopes. Detailed phenotypic analysis of the HIV-specific CD8 cells demonstrated low perforin levels and persistent expression of CD27, a phenotype associated with incomplete differentiation of cytotoxic T lymphocytes (CTL).ConclusionThis immature CTL phenotype has been described previously in association with chronic HIV disease, but its continued persistence is surprising in the setting of prolonged viral suppression on therapy and the presence of HIV-specific CD4 cell activity.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo utilize the potent antigen-presenting capacity of mature dendritic cells (MDC) in order to develop a rapid, sensitive method for quantifying antigen-specific CD8 T cells present at low frequency in peripheral blood.DesignPeripheral blood mononuclear cells (PBMC) were obtained from seven HIV-1-positive individuals with low to moderate CD8 T cell responses, including five on highly active antiretroviral therapy (HAART). IFN-γ ELISPOT assays were performed using either monocytes or MDC to present antigens expressed by recombinant vaccinia viruses (r-VV).MethodsPeripheral blood-derived monocytes were cultured for 5–6 days in the presence of IL-4 and granulocyte macrophage colony-stimulating factor, then matured in monocyte-conditioned medium. MDC were infected with r-VV and co-cultured in an ELISPOT assay with autologous monocyte-depleted PBMC.ResultsRelative to autologous monocytes, MDC amplified detection of antigen-specific CD8 T cells by 2–30-fold in response to antigens from HIV-1, Epstein–Barr virus and cytomegalovirus. Furthermore, antigenic specificities were revealed that had not been detected using standard ELISPOT of PBMC.ConclusionThis assay will prove useful for the detection of memory T cells present at low frequency, and may be of interest for identifying subdominant cytotoxic T lymphocyte epitopes. This method may have broad applications for the detection of antiviral CD8 T cell responses in patient populations in whom such responses have been difficult to detect, including HIV-1-seropositive individuals with advanced disease or undergoing HAART.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo investigate the immunological and virological interactions between interleukin (IL)-15 and HIV in antiretroviral-naive and highly active antiretroviral therapy (HAART)-treated patients.DesignThree groups of HIV-infected patients were studied: 20 untreated patients with advanced disease; eight patients with viral suppression and immunological response to HAART; and 10 patients with virological and immunological treatment failure. Eleven healthy blood donors were included as controls.MethodsThe following parameters were evaluated: the production of IL-15 by peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide,Candida albicansandMycobacterium aviumcomplex; the ability of IL-15 to induce the secretion of IL-8 and monocyte chemotactic protein-1 (MCP-1) from HIV-positive monocytes; and the virological effect of IL-15 and IL-2 on HIV replication in mononuclear cells.ResultsIL-15 production by PBMC was significantly decreased in antiretroviral-naive patients and in those with treatment failure. On the contrary, in patients with response to HAART IL-15 production was comparable to that of healthy donors. IL-15 was able to stimulate HIV-positive monocytes to produce chemokines, such as IL-8 and MCP-1, that specifically attract neutrophils and monocytes to the site of inflammation thus possibly improving immune response to pathogens during HIV infection. Finally, IL-15 had no major effect on HIV replicationin vitro, while only simultaneous administration with IL-2 may induce high levels of HIV production.ConclusionsThisin vitrostudy provides new insights in the area of IL-15–HIV interactions and suggests that IL-15 may represent a potential candidate for cytokine treatment in combination with HAART during HIV infection.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo measure HIV-1 quasispecies diversity in very recently infected male and female plasma donors.MethodsHIV-1 RNA testing of blood and plasma donations was used to select anti HIV-1 antibody negative, HIV-1 RNA positive plasma samples from 13 males and four females undergoing primary infection. To determine whether these early viral populations were clonal or oligoclonal, heteroduplex mobility assays were performed on multiple independently generated envelope PCR products. Genetically heterogeneous quasispecies where subcloned and their divergent envelope variants sequenced.ResultsBecause of frequent plasma donations in this population, HIV-1 RNA quasispecies could be studied during very early primary infection. Heteroduplex mobility assays detected the presence of genetically distinct variants in four of the 17 plasma donors. DNA sequence analysis showed that one case was due to a G to A hyper-mutation event and that two cases were caused by the presence of in-frame insertions/deletions resulting in DNA heteroduplex mobility shifts. The early plasma quasispecies of one female contained highly divergent variants differing by up to 6% substitution and multiple insertions/deletions, a level of divergence unlikely to have been generatedde novofollowing transmission. V3 loop sequences analysis indicated the presence of non-syncitium inducing genotypes in 14 out of 17 primary infection cases.ConclusionPlasma viremia is generally genetically homogeneous even during the very early phase of primary infection when viremia is first detected and still rising exponentially. Evidence for the transmission of multiple variants was detected in only one out of four women and none of 13 men undergoing primary infection with subtype B HIV-1.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectivesThis study addresses the detailed expression of natural killer (NK)- associated receptors on CD8 T lymphocytes in treatment-naive HIV-infected individuals.DesignExperimental study analysing the expression of NK-associated receptors on peripheral blood T lymphocytes from HIV-infected individuals compared with healthy controls.MethodsFlow cytometry was used to analyse the expression of CD56, CD16, CD94, NKG2A, NKB1, CD161, CD244, and perforin, according to the CD28 phenotype, on CD8brightT cells obtained from treatment-naive HIV-infected individuals and from healthy controls.ResultsThe results showed that CD8brightT cells from treatment-naive HIV-infected individuals had a decreased expression of CD56 and that CD8brightCD56 cell numbers correlated with CD4 cell counts. NK-associated markers were preferentially expressed on CD8brightCD28 negative T cells, both in healthy controls and HIV-infected individuals. An increased expression of CD94, CD244, and perforin, which was the consequence of the expansion of the CD8brightCD28 negative T-cell subset, was also observed in HIV infection.ConclusionsAs the CD8brightCD56 T cells are the mature cytolytic effector cells, the defective expression of CD56 on CD8brightT cells shown in HIV-infected individuals could be involved in the decreased peripheral blood T-cell cytotoxicity found in HIV infection.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundSustained elevations in CD4 cell counts commonly occur despite incomplete viral suppression with protease inhibitor-based antiretroviral therapy.ObjectivesTo determine the incidence and risk factors associated with return of CD4 cell count to pre-therapy levels in patients experiencing virologic failure of protease inhibitor therapy.DesignThis is a clinic-based cohort study of HIV-infected adults who failed to maintain durable viral suppression on a protease inhibitor-based regimen.Main outcome measuresVirologic failure was defined as persistent plasma HIV RNA level > 500 copies/ml. Immunologic failure was defined as return of CD4 cell count to pre-therapy levels.ResultsA total of 291 patients experienced virologic failure on a protease inhibitor-based regimen and had a treatment-mediated CD4 cell increase above pre-therapy levels at the time of virologic failure. If patient data were censored at the time a successful salvage regimen was initiated, then the median time to immunologic failure after the onset of virologic failure was 3 years. If patient data were also censored at the time therapy was discontinued, then 36.8% of the cohort experienced immunologic failure after 3 years of continuous virologic failure. The change in viral load from a pre-treatment baseline, and not the absolute level of viremia achieved, was a strong and independent predictor of immunologic failure. Discontinuing therapy was associated with immunologic failure independent of viral load changes.ConclusionReduction in T CD4+ cell numbers may eventually occur during prolonged virologic failure of a protease inhibitor-based regimen and is predicted by the degree of virologic suppression below a pre-therapy ‘set-point'.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo determine whether HIV-1 genotyping and expert advice add additional short-term virologic benefit in guiding antiretroviral changes in HIV+ drug-experienced patients.DesignA two factorial (genotyping and expert advice), randomized, open label, multi-center trial. The patients were stratified according to the number of treatment failures.Patients and methodsHIV-1 infected patients on stable antiretroviral therapy who presented virological failure were included into the study. Genotypic testing was performed by using TrueGene HIV Genotyping kit and the results were interpreted by a software package (RetroGram®, version 1.0). An expert advisory committee suggested the new therapeutic approach based on clinical information alone or on clinical information plus HIV-1 genotyping results. Plasma HIV-1 RNA load, CD4+ cell count and adverse events were recorded at baseline and every 12 weeks.ResultsA total of 326 patients were included. The baseline CD4+ cell count and plasma HIV-1 RNA were 387 (± 224) × 106cells/l and 4 (± 1) log10respectively. The proportion of patients with plasma HIV-1 RNA < 400 copies/ml at 24 weeks differed between genotyping and no genotyping arms (48.5 and 36.2%,P< 0.05). Factors associated with a higher probability of plasma HIV-1 RNA < 400 copies/ml were HIV-1 genotyping [odds ratio (OR), 1.7; 95% confidence interval (CI), 1.1–2.8;P= 0.016] and the expert advice in patients failing to a second-line antiretroviral therapy (OR, 3.2; 95% CI, 1.2–8.3;P= 0.016).ConclusionsHIV-1 genotyping interpreted by a software package improves the virological outcome when it is added to the clinical information as a basis for decisions on changing antiretroviral therapy. The expert advice also showed virologic benefit in the second failure group.

ISSN:0269-9370    

出版商:OVID    

年代:2002

数据来源: OVID