ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Knowledge about B-cell dysfunction and HIV-specific antibody production is necessary for the understanding of both HIV-1-related immunopathology and the (vaccine-induced) humoral immunity involved in protection against AIDS. This paper describes the application of recently developed methods to detect epitope specificity of B cells in lymph-node biopsies with antigen–enzyme conjugates. Cryosections of five lymph-node biopsies from HIV-1-infected individuals and four control tissues were stained with a panel of HIV-1 antigen–enzyme conjugates: recombinant HIV-1 proteins (gp160, gp120 and p24), labelled with peroxidase, and synthetic peptides representing neutralizing epitopes from gp120 and gp41, labelled with alkaline phosphatase. Antibody-forming cells (AFCs) were detected in all the HIV-1-infected biopsies with gp160, gp120 and/or p24, in numbers up to 350 per section. AFCs producing specific antibodies against peptide 101 (SP 101), representing the neutralizing epitope 586–608 of gp41, were detected in one patient. These techniques allow correlation ofin vivofunction of–B cells with lymph-node pathology, clinical stage of the disease and serological data. Their potential for the elucidation of HIV-related immunopathogenesis and the development of vaccines is discussed.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Reclustering and indirect immunofluorescence assays on MT-4 cells [carrying both CD4 and complement receptor type 2 (CR2)] were used to measure neutralizing and enhancing antibodies in sera obtained from HIV-1-infected individuals. Heat-inactivated sera were tested before and after mixing 1:1 with fresh seronegative human serum. Using heated samples, neutralizing antibodies were found in 20 out of 20 and 11 out of 19 serum samples of asymptomatic and symptomatic [AIDS, AIDS-related complex (ARC)] HIV-seropositive patients, respectively. In complement-restored samples, neutralizing activity was found in eight sera of asymptomatic patients and in none of the sera of AIDS and ARC patients; enhancing activity could be detected in four and 12 sera, respectively. A significant positive correlation was observed between the titres of neutralizing antibodies measured in the complement-restored samples and the absolute number of CD4+ lymphocytes. These findings indicate that the appearance of complement-dependent enhancing antibodies coincident with the loss of neutralizing antibodies may indicate a poor prognosis in HIV infection.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Previous studies have shown that infection of complement receptor (CR2)-bearing cells with HIV pretreated with antibody (Ab) plus complement (C) resulted in increased virus expression. The current study was designed to determine whether C-mediated ‘enhancement’ of HIV-1 production was the result of increased virus infection of cells as assessed by provirus formation and virus binding. Virus was incubated with anti-HIV Ab and/or C and added to CR2-positive MT-2 cells. Increased virus expression by MT-2 cells correlated with increased numbers of HIV-immunofluorescent-positive cells at 24 and 48 h and higher levels of provirus detected 8–28 h after infection. MT-2 cells also bound threefold more Ab-plus-C-treated virus than untreated virus. Serial dilutions of C showed that high levels of C with Ab did not enhance but rather suppressed virus expression. Studies were also performed which showed that terminal C components C5 and C8 were not necessary for the enhancing effect. The increased binding of C-coated HIV to CR-positive cells has important implications for the fate of virusin vivo.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Three human colonic epithelial cell lines, SW620, HT29, and T84, were characterized with respect to HIV-1 infection and gene expression. SW620 and HT29, but not T84, could be infected with HIV-1. CD4 messenger RNA and its protein product were identified in SW620 cells but not in HT29 or T84 cells. Anti-CD4 antibody blocked infection of SW620 cells but had no effect on infection of HT29 cells. In SW620 and HT29 cells transfected with the HIV-1 long terminal repeat (LTR) linked to the chloramphenicol acetyl transferase (CAT) reporter gene, an intact HIV-1 enhancer element was required for stimulation of CAT activity by tumor necrosis factor α (TNFα) and phorbol ester. T84 was not able to mediate a TNFα or phorbol ester response. These studies provide further evidence that HIV-1 can infect cells by mechanisms other than those mediated by the CD4 receptor and describe complementary models for analyzing HIV-1 infection and expression in colonic epithelial cells.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We conducted a study of 152 HIV-1-seropositive individuals in order to evaluate the possible correlations between the isolation of HIV from peripheral blood mononuclear cells or from plasma and CD4 cell counts. HIV was isolated from only 36% of plasma samples, and the isolation rate was closely related to CD4 cell counts, increasing gradually from 0% in subjects with > 800 x 106/l CD4 cells to 88% in those with < 100 x 106/l CD4 cells. In contrast, HIV was isolated from 92% of cell samples (99% in subjects with < 900 x 106/l CD4 cells, 46% in those with CD4 counts ≥ 900 x 106/l). Since most cell samples were positive, a scoring method was designed to quantify the cellular viral load. The results obtained demonstrated that the cellular viral load was closely related to CD4 counts. We also found that the cellular viral load was higher in subjects with either positive plasma isolation or positive p24 antigenaemia. The measurement of the cellular viral load by this scoring method appears to be useful for the management of HIV-seropositive individuals and for the evaluation of therapeutic trials.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

This study examined 2',5'-oligoadenylate (2,5A) synthetase activity in 26 individuals during the asymptomatic phase of HIV infection and its correlation with neopterin or β2-microglobulin. In HIV-antibody-positive (HIV-Ab+) asymptomatic people, both neopterin and β2-microglobulin levels in sera were significantly elevated; in contrast, 2,5A-synthetase activity in peripheral blood mononuclear cells was not significantly higher than in HIV-antibody-negative controls. The 2,5A-synthetase levels in symptomatic people (AIDS-related complex and AIDS) were significantly higher than in either asymptomatic or control individuals. However, within the group of HIV-infected asymptomatic individuals, all three markers were positively correlated. In this group, neopterin values were negatively correlated with the number of CD4+ lymphocytes while a positive correlation was found between 2,5A-synthetase and the number of CD8+ lymphocytes. Asymptomatic people with detectable serum HIV p24 antigen had significantly higher 2,5A-synthetase, neopterin, β2-microglobulin and number of CD8+ lymphocytes. This study suggests that elevated 2,5A-synthetase activity may reflect a different aspect of host response to HIV infection than do elevated neopterin or β2-microglobulin.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

We present the baseline results of a prospective cohort study on the perinatal transmission of HIV-1 in Kigali, Rwanda. HIV-1-antibody testing was offered to all women of urban origin delivering a live newborn at the maternity ward of the Centre Hospitalier de Kigali from November 1988 to June 1989; 218 newborns of 215 HIV-positive mothers were matched to 218 newborns of 216 HIV-negative mothers. The matching criteria were maternal age and parity. No differences in socioeconomic characteristics were observed between HIV-positive and HIV-negative women. HIV-positive mothers more frequently reported a history of at least one death of a previously born child (P< 0.01) and a history of abortion (P< 0.001). Most of the HIV-positive women were asymptomatic, but 72.4% of them had a CD4: CD8 ratio < 1 versus 10.1% in the HIV-negative group (P< 0.001). The frequency of signs and symptoms was not statistically different in the two groups, except for a history of herpes zoster or chronic cough, which was more frequent among HIV-positive women. The rates of prematurity, low birth weight, congenital malformations and neonatal mortality were comparable in the two groups. However, infants of HIV-positive mothers had a mean birth weight 130g lower than the infants of HIV-negative mothers (P< 0.01). The impact of maternal HIV-1 infection on the infant seems limited during the neonatal period.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

During 11 months in 1989–1990, 1009 consecutive hospitalized adult patients admitted to the medical wards of the National Hospital in Bissau were interviewed, examined clinically, and tested for antibodies to HIV-1 and HIV-2. The prevalence of HIV-2 infection was 20.4% (206 out of 1009) and of HIV-2-associated AIDS 4.4% (44 out of 1009). HIV-2 infection was more frequent in women (25%, 110 out of 440) than in men (16.9%, 96 out of 569). HIV-1 infection was diagnosed in one patient only, and one patient (with AIDS) had reactivity to both HIV-1 and HIV-2. Among HIV-2-seropositive patients, AIDS was demonstrated in 21.3% and AIDS-related symptoms (not fulfilling the AIDS criteria) in 19.4%. The frequency of AIDS-associated symptoms was significantly higher in HIV-2-seropositive patients than in seronegative patients. The clinical profile of the HIV-2-associated AIDS cases was very similar to that described in HIV-1-associated AIDS cases in Africa. Seven out of 51 patients fulfilling the clinical criteria for AIDS were HIV-seronegative. The World Health Organization (WHO) clinical case definition for AIDS in Africa had a specificity of 99% and a positive predictive value of 86%. Tuberculosis was more common in HIV-2-seropositive patients (6.3%) than in HIV-2-seronegative patients (2.2%). A history of blood transfusion was a significant risk factor for HIV-2 infection. HIV-2 infection and AIDS are public health problems in Guinea-Bissau.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Twenty-six patients with poor-risk Kaposi's sarcoma and AIDS were treated with epirubicin 90 mg/m2intravenously every 3 weeks. One patient achieved complete response and 10 achieved partial response (overall response rate 42.3%). The median time to treatment failure was 22 weeks. The dose-limiting toxicity was neutropenia.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID