摘要:

Objective:To compare the performance of V3-loop peptide enzyme immunoassay (PEIA) methodologies from four different laboratories for subtyping HIV-1, and to determine the causes for the lack of correlation between V3-loop PEIA serotyping and subtyping by sequencing.Materials and methods:Synthetic peptides derived from the amino-acid consensus sequences of the V3-loop of group M strains representing genetic subtypes A–F as well as reference strains were evaluated in PEIA by four different laboratories for their ability to accurately determine the subtype in a panel of 85 sera obtained from persons infected with known HIV-1 subtypes (28 subtype A, 34 subtype B, four subtype C, 10 subtype D, seven subtype F, one each of subtype H and G). Furthermore, the V3 loop of the corresponding virus was compared with the V3 loop of the peptides used in PEIA.Results:The correlation between HIV-1 subtyping by sequencing and V3-loop PEIA from the different laboratories varied considerably for the different HIV-1 subtypes: subtype A (46–68%), B (38–85%), C (75–100%), D (29–50%), and F (17–57%). A 70% agreement between PEIA and sequencing subtypes was observed for samples with the concordant presence of the same octameric sequences in the V3 loop of the virus and the V3 loop of the peptide used in PEIA; however, only 42% of specimens with different V3-loop octameric viral and peptide sequences yielded concordant results in V3-loop serotyping and genetic subtyping.Conclusion:Our results indicate that V3-loop PEIA methodologies used in different laboratories correlate poorly with genetic subtyping, and that their accuracy to predict HIV-1 subtypes in sera of Belgian individuals infected with different HIV-1 subtypes (A, B, C, D, F, G and H) vary considerably. The poor correlation between serotyping and genetic subtyping was partly due to the simultaneous occurrence of subtype-specific octameric sequences at the tip of the V3 loop of viruses belonging to different genetic subtypes.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Design:Envelope protein-specific antiviral peptides, called mucibodies, that can specifically recognize and bind to the surface unit protein gp120 of HIV-1 were designed. The initial mucibody binding target was the V3 loop of HIV-1 gp120. Here, the gp120–CD4 binding domain was chosen as the site of mucibody binding. The CD4 binding domain of gp120 is known to be a conformational epitope and is involved in the earliest events of viral entry into many cells.Methods:The design of the mucibody antivirals was based on previous observations that antibody complementarity determining regions (CDR) are generally similar to the repeating loops or knob structures found in the 20-residue tandem repeat domain of human mucin MUC1. The heavy chain CDR3 from the bacteriophage display antibody b12 was used to construct two mucibodies, b12-CDR1 and b12–26.Results:Peptides corresponding to three tandem repeats were shown to bind directly to the CD4 binding domain of HIV-1 gp120 in a solid-phase enzyme-linked immunosorbent assay. These mucibody peptides also disrupted the gp120–CD4 interaction in a solution-phase inhibition assay. Finally, mucibodies neutralized primary and laboratory macrophage-tropic isolates of HIV-1.Conclusions:There is a potential for medical use of these peptides as topical vaginal microbicides in preventing HIV-1 transmission during sexual contact. These results also suggest that multivalent, non-immunogenic binding proteins of virtually any specificity could be constructed for use in therapeutic applications involving infectious diseases and immune system dysfunction.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To improve the detection rate of HIV-2 proviral DNA in primary uncultured peripheral blood mononuclear cells (PBMC) of HIV-2-seroreactive and HIV-1-HIV-2 dually seroreactive individuals.Materials and methods:Two newly designed HIV-2 PCR primer pairs in the long terminal repeat (LTR)gagandgag-polregions and a previously describedenvand LTR HIV-2 PCR primer pairs were tested on samples from 66 confirmed HIV-2-seropositive individuals (The Gambia, 40; Côte d'Ivoire, 17; Guinea-Bissau, nine), 209 dually seroreactive individuals (The Gambia, 82; Côte d'Ivoire, 127), 24 genetically characterized isolated HIV-1 strains (group M subtypes A-H and group O), one simian immunodeficiency virus (SIV) strain cpz, 10 HIV-2 isolates (subtype A, B and unidentified), two SIVsmisolates, and 10 seronegative samples.Results:All HIV-2 primers evaluated showed 100% specificity since there was no amplification observed with 24 HIV-1, one SIVcpzand 10 seronegative samples. One single copy of the HIV-2 genome could be detected with all outer primer pairs as well as all inner primer pairs on one PCR round used. Sensitivity of primers (at least one of the four primer pairs was positive) to HIV-2-seropositive samples was 100% (all nine) in Guinea-Bissau, 71% (12/17) in Côte d'Ivoire, 100% (all 20) in Gambian AIDS patients, and 85% (17/20) in Gambian pregnant women. Doubling the PBMC of dually seroreactive individuals from 7.5 × 104to 1.5 × 105in the PCR revealed the presence of both HIV-1 and 2 proviral DNA in 72% (92/127) in Côte d'Ivoire and 72% (59/82) in The Gambia. By doubling the number of PBMC, HIV-2 detection in dually seroreactive individuals by PCR was increased from 65 to 77% in Côte d'Ivoire and from 67 to 83% in The Gambia.Conclusions:The use of 1.5 × 105 primary uncultured PBMC and the newly designed HIV-2 primer pairs allowed us to document the highest percentage (72%) ever reported of HIV-1–HIV-2 dual infections amongst HIV-1–HIV-2 dually seroreactive individuals in Côte d'Ivoire and The Gambia. Improved detection of HIV-2 proviral DNA, rather than exposure to both viruses, infection with only one virus, or infection with a unique third virus containing epitopes common to both HIV-1 and HIV-2, contributes to a more accurate monitoring of the prevalence of HIV-1–HIV-2 dual infections.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objectives:To determine immunodominant regions and new epitopes for cytotoxic T cells (CTL) directed against the HIV-1polproducts reverse transcriptase (RT), integrase and protease in a large cohort of patients at different stages of disease.Design and methods:Cross-sectional analysis of 98 patients from the French IMMUNOCO cohort (CD4 counts: 125–1050 × 106cells/l), monitored for CTL recognition of HIV-1polproducts using recombinant vaccinia virus constructs and synthetic peptides.Results:Memory CTL responses against HIV-1polproducts were detected in 78% of all patients whatever the stage of disease. RT was more immunogenic (81%, 30 out of 37 patients) than integrase and protease (51% and 24%, respectively). CTL recognition of RT was more frequent against Pol amino acids 310–460 (61%, 11 out of 18 patients) than against the other three portions (Pol 168–310, Pol 450–600, Pol 590–728) in patients with CD4 counts > 400 × 106/l, whereas in patients at advanced stages no prominent differences were observed. Two new clusters of antigenic regions were found in the NH2segment: three epitopes between amino-acids Pol 200 and 217 and four epitopes between amino-acids Pol 346 and 387, using five different HLA-restricting elements. A new cluster of three conserved epitopes was found in the COOH segment of RT.Conclusions:This study shows that memory CTL responses against HIV-1 RT, integrase and protease are detectable in most patients at different stages of disease. The capacity of CTL to recognize simultaneously clusters of epitopes may become important for the immune control to reinforce antiretroviral drug efficiency.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:This study was performed to investigate the hyporeactivity of purified B lymphocytes from HIV-1-infected patients.Design:Given the importance of the B-cell Ag receptor (BCR) and CD40 in B-lymphocyte activation, we assessed the capacity of purified peripheral blood B lymphocytes from HIV-1-infected patients to differentiate into Ig-secreting cells in a T-cell- and accessory-cell-independent system of BCR and CD40 costimulation.Methods:B lymphocytes from 21 HIV-1-infected patients were purified by immunomagnetic cell separation and costimulated with immobilized anti-CD40 monoclonal antibodies andStaphylococcus aureusCowan I particles in the presence of interleukin (IL)-2 and IL-10. Homotypic aggregate formation, apoptosis, cell cycle entrance, proliferation and Ig secretion of B cells were analysed.Results:Costimulation by the BCR and CD40 induced proliferation and differentiation of B lymphocytes into Ig-secreting cells in 13 patients (group I) but not in eight patients (group II). For three patients in group II, the dual triggering induced apoptosis of B cells. The unexpected inability of these cells to differentiate was associated with a high CD38 expression and a weak spontaneous production of Ig or anti-HIV-1 antibodies in patients with a high viral load and a low CD4+ lymphocyte count. Despite this anomaly, the B cells from group II were able to progress through the cell cycle after stimulation with a combination of phorbol ester and ionomycin in complete medium, suggesting an impairment in BCR and CD40 early signal transduction.Conclusion:Intrinsicin vitrohyporeactivity of B lymphocytes to dual triggering of BCR and CD40 was observed in advanced HIV-1 disease and appeared to be related toin vivohyperactivation of B cells.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To determine the relationship betweenMycobacterium tuberculosisinfection and disease and subsequent disseminatedM. aviumcomplex (MAC) disease in HIV-infected persons.Design:A prospective observational cohort study.Setting:The AIDS Linked to the Intravenous Experience (ALIVE) cohort of injecting drug users and the Johns Hopkins Hospital Adult HIV Clinic (JHHAHC).Participants:HIV-infected persons aged > 18 years with CD4 lymphocytes < 100 × 106/l were followed between July 1989 and 31 October 1996. There were 182 persons in the ALIVE cohort and 1129 persons in JHHAHC who met these criteria.Main outcome measure:The relative risk of disseminated MAC was determined according to a history of prior opportunistic infection, MAC prophylaxis, antiretroviral therapy,M. tuberculosisinfection or disease, race, sex, and injecting drug use.Results:Amongst the 30 patients with active tuberculosis, eight developed disseminated MAC, compared with 208 cases of disseminated MAC amongst 1148 patients without priorM. tuberculosisinfection or disease [relative risk (RR), 1.5; 95% confidence interval (CI), 0.8–2.7;P= 0.2]. Amongst the 10 patients with extrapulmonary tuberculosis, five developed disseminated MAC (RR, 2.8; 95% CI, 1.5–5.2;P= 0.02). Injecting drug use was associated with a decreased risk of disseminated MAC (RR, 0.7; 95% CI, 0.6–0.9;P= 0.007). In a logistic regression analysis, disseminated MAC was significantly associated with extrapulmonary tuberculosis and other opportunistic disease, whereas antibiotic prophylaxis and injecting drug use were protective.Conclusions:A history ofM. tuberculosisinfection or disease was not associated with protection against subsequent disseminated MAC disease in HIV-infected persons. However, persons with extrapulmonary tuberculosis were at increased risk for disseminated MAC, particularly at low CD4 cell levels.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:Advanced HIV disease is associated with a high prevalence of cervical squamous intra-epithelial lesions (SIL) and of infection with oncogenic human papillomavirus (HPV) genotypes. Triple-combination antiretroviral therapy results in decreased plasma HIV viral load, increased CD4 cell counts and partial restoration of immune functions in patients with severe HIV disease. This study investigated the outcome of SIL in HIV-seropositive women undergoing triple combination antiretroviral treatment.Methods:Forty-nine women who started triple-combination antiretroviral therapy, including a protease inhibitor, were examined prior to and after a median 5-month treatment. We collected cytological, colposcopic and histologic data and assessed the presence of HPV DNA in cervical smears by PCR and Southern blot hybridization (SBH).Results:The prevalence of SIL decreased from 69 to 53% during follow-up (P< 0.0001). Among 13 women who initially presented with high-grade SIL, conversion to lower grade was observed in two women and a full regression to normality was observed in one. Cytology also returned to normality in nine out of 21 women who initially presented with low-grade SIL. The high prevalence of HPV infection as detected by SBH and PCR was similar at the first and second examinations and the same high-risk viral genotypes were identified at both examinations in all infected patients but one. There was a higher increase in absolute CD4 cells in the subgroup of patients whose lesions regressed (99 versus 50 × 106/l,P= 0.03).Conclusion:Our observations demonstrate that active antiretroviral therapy may result in a reduced prevalence of cervical squamous intra-epithelial lesions despite the absence of clearance of HPV infection. © 1998 Lippincott-Raven Publishers

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objectives:Assessment of genotypic change in HIV protease during treatment with saquinavir (SQV) in combination with zidovudine (ZDV) and/or zalcitabine (ddC), to determine the influence of such changes on viral phenotype and response to treatment.Design:Virologic substudies of Phase III clinical trials NV14256 and SV14604.Methods:Population sequencing of HIV protease genes amplified from pre- and post-treatment plasma. Phenotyping of peripheral blood mononuclear cell (PBMC)- derived virus isolates, and genotyping of proviral DNA clones amplified from PBMC used in the expansion of virus isolates.Results:In both trials the incidence of Met90 remained at ≤ 20% in subjects receiving SQV in combination with ddC (with or without ZDV) for 1 year. A Val48 substitution was observed in two out of 81 subjects after 24 weeks and in two out of 75 subjects after 48 weeks. In 12 out of 13 NV14256 subjects with viral load rebound during SQV monotherapy these substitutions were associated with the rebound. In subjects treated with SQV plus ddC, rebound was associated with SQV resistance in six out of 22 cases and ddC resistance in five out of 22 cases. The incidences of non-BRU residues at positions 10, 63 and 71 were increased significantly (P< 0.05, Fisher's exact test) after SQV treatment with or without ZDV. However, comparison of genotypic and phenotypic data showed that these changes were not associated with reduced sensitivity to SQV.Conclusions:Virological failure during combination therapy can be due to resistance to either treatment drug, emphasising the need to change both the reverse transcriptase inhibitor and the protease inhibitor. Only Val48 and Met90 correlated directly with the development of reduced drug sensitivity during treatment with SQVin vivo.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To determine the effect of Kaposi's sarcoma on survival of HIV-infected patients.Methods:Retrospective cohort study to compare the survival of 241 HIV-infected homosexual patients with Kaposi's sarcoma (cases) with that of 241 HIV-infected homosexual patients without Kaposi's sarcoma (control subjects) but with a similar level of immunosuppression (measured by the absolute CD4+ lymphocyte count).Results:Cases and control subjects were similar in age, occurrence of previous opportunistic infections, and the use of antiretroviral therapy. The mean CD4+ lymphocyte counts were similar for cases and control subjects (185 × 106versus 184 × 106/l, respectively). Cases had a higher incidence of opportunistic infections (5.95 versus 3.88 infections, respectively, per 100 person-months of observation) and a greater number of infections typical of late-stage HIV infection. Cases had a shorter overall survival than did control subjects (P= 0.0025). Kaposi's sarcoma was associated with an increased risk of death (odds ratio, 1.28), even when adjusting for age, previous opportunistic infection, baseline CD4+ lymphocyte count, and antiretroviral therapy.Conclusion:Kaposi's sarcoma appears to accelerate the clinical course of HIV infection. Opportunistic infections develop earlier and more often in patients with the disease than in control subjects. Survival was significantly shorter in patients with Kaposi's sarcoma.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objectives and design:The dynamics of viral decline following the initiation of antiretroviral treatment were studied in 29 HIV-1-infected patients participating in a two-arm trial comparing immediate (group A: ritonavir, zidovudine and lamivudine) and delayed (group B: ritonavir supplemented by zidovudine and lamivudine on day 21) triple therapy. Parameters underlying viral dynamics were estimated using mathematical models tailored to these treatment protocols.Results:The decline in plasma HIV-1 density between day 0 and 21 was steeper in group A (−2.27 ± 0.46 log10) than group B (−1.87 ± 0.56 log10). In a subset of patients amenable to full mathematical analysis, a short-lived productively infected cell compartment (producing ∼97% of total virions) decayed with a half-life of 1.0–2.5 days, whereas a long-lived infected cell compartment decayed with a half-life of 18.8–32.8 days. Estimates for the time for the elimination of virus from these two cell populations ranged from 474 to 802 days. The rate of loss of productively infected CD4+ T cells was positively correlated with baseline viral load in group A and in the combined dataset.Conclusions:These results suggest that HIV-infected cell populations may have a faster turnover in patients with higher viral loads due to higher infection rate parameters, higher rates of virus production, or lower virus clearance rates.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID