摘要:

We developed a transfection-neutralization assay for human immunodeficiency virus type 1 (HIV-1) infectious molecular clones. In this assay CD4 negative adherent cells, transfected in microtiter plates with fixed amounts of proviral DNA of molecular HIV-1 clones, are cocultivated with CD4 positive T cell lines or primary peripheral blood mononuclear cells (PBMC) in the presence of anti-HIV-1 sera or monoclonal antibodies (MAbs). Results obtained with this technique were reproducible and compared favorably with a conventional cell-free infection inhibition assay. The transfection-neutralization assay obviates the need for virus stock preparation and, therefore, is particularly suitable for the evaluation of HIV-1 clones with slow replication kinetics and of recombinant chimeric HIV-1 clones inclined to undergo additional mutations during stock preparation. The potential value of this assay for the analysis of the specificity of neutralizing sera and MAbs was demonstrated in experiments with V3 chimeric molecular clones.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

In vitro polyclonal activation of peripheral blood mononuclear cells (PBMCs) from 70% of the simian immunodeficiency virus (SIV) serum enzyme-linked, immunosorbent assay (ELISA)–negative sooty mangabeys leads to synthesis and release of low but significant and reproducible levels of SIV-reactive antibodies, as determined by ELISA and Western blot analysis. The predominant isotype of SIV-reactive antibodies in the pokeweed mitogen (PWM) supernatant fluids from serum ELISA-negative mangabeys is IgM, whereas the predominant isotype of SIV-reactive antibodies in seropositive mangabeys is IgG. Depletion of CD8+cells led to a marked increase in the levels of SIV-reactive antibodies detected in supernatant fluids from PWM-induced cultures from the serum ELISA-negative mangabeys. No evidence for such SIV-reactive antibodies has been found, to date, in similar unfractionated or CD8+T-cell-depleted PWM-induced PBMC cultures from uninfected macaques. Supernatant fluids from PWM cultures of PBMCs from a select group of serum ELISA-negative mangabeys, when concentrated five times, were shown to give a Western blot profile against SIV, similar to the profile seen with plasma from seropositive infected macaques and mangabeys. Evidence is presented to show that these serum ELISA-negative mangabeys are most likely latently infected with SIV. This evidence, which was obtained in samples from such ELISA-negative mangabeys, includes the detection of reverse transcriptase activity and the presence of SIV p27 in supernatant fluids of phytohemagglutinin-stimulated PBMCs in vitro. In addition, the data show the presence of CD8+T cells that regulate SIV-specific Ig synthesis and show the detection ofgagsequences by the polymerase chain reaction. Thus, the PWM assay described herein may provide a valuable additional tool for detection of lentivirus infection before or in the absence of seroconversion.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

We investigated the capacity of two immunostimulating-complex (iscom) formulations including inactivated native HIV-2 viral proteins and selected peptides to induce protective immunity against HIV-2 in a nonhuman primate. Four cynomolgus monkeys were first immunized with five i.m. injections of purified detergent-disrupted HIV-2 virions (total dose, 0.7 mg) in iscoms over a period of 16 months. At months 18 and 20, all four macaques were given booster immunizations with iscom-coupled V3-derived synthetic peptides representing a dominating neutralizing region of HIV-2 gp125. Two weeks after the final dose of vaccine, the four vaccinated animals, together with four controls, were challenged i.v. with 10 monkey infectious doses (MID50) of monkey-cell–grown homologous cell-free virus, HIV-2SBL-6669/H5. After the challenge, the four control animals became readily infected; however, three of four vaccinated animals were protected as shown by repeated negative virus isolations and negative polymerase chain reaction for viral DNA and by failure to transmit HIV-2 infection with whole blood and lymph node cells into naive cynomolgus macaques. One of three protected animals showed an anamnestic antibody response to a dominating antigenic site, indicating possible limited virus replication. The vaccine-protected monkeys were subsequently resistant to rechallenge infection at 12, 15, and 18 months after the first challenge, suggesting that a reasonable duration of protective immunity had been induced by the vaccine.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Oligonucleotide compounds composed of only deoxyguanosine and deoxythymidine were able to significantly inhibit human immunodeficiency virus type −1 (HIV-1)–induced syncytium formation and virus production (as measured by p24 core antigen expression) in an acute infection assay system. The oligonucleotides did not share any homology with or possess any complementary (antisense) sequence motifs to the HIV-1 genome. The guanosine/thymidine–containing oligonucleotides (GTOs) that showed this anti-HIV activity contained natural phosphodiester (PD) linkages (backbones) between the nucleosides. One of the PD oligonucleotide sequence motifs tested was capable of inhibiting HIV-1-induced syncytium formation and p24 production with a median effective dose in culture (ED50) in the submicromolar range. In addition, oligonucleotides tested were able to significantly suppress HIV-1 p24 levels ≥7 days after removal of the drug from the infected cell culture medium. The growth inhibition properties (toxicity) of this genre of oligonucleotides was determined to be well above the ED50values yielding high selective indexes. In vitro results showed that GTOs with PD backbones were potent competitive inhibitors of HIV-1 reverse transcriptase. These same molecules were capable of blocking the interaction between gp120 and CD4. All measured activities of these molecules were increased by factors of 10–500 when the PD backbone was replaced with a PT backbone in a sequence-dependent manner. The enhanced antiviral activity displayed by the sulfur group on the oligonucleotide backbone and the lack of any sequence-specific interactions suggest that a percentage of antiviral activity of oligonucleotide-based therapeutics is due to mechanisms other than those originally postulated for oligonucleotides. The good selective index of GTOs coupled with the prolonged suppression of HIV-1 in culture after removal of oligonucleotides from the infected cell culture make this a class of compounds that warrant investigation as therapeutic agents to be used against HIV-1.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Human immunodeficiency virus type 1 (HIV-1)–infected individuals, but not HIV-seronegative controls, have non–HLA-restricted T-cell receptor αβ+CD8+cytotoxic T-lymphocytes (CTL) that kill activated uninfected CD4+lymphocytes. In vitro stimulation of peripheral blood mononuclear cells from HIV-1-infected individuals with concanavalin A (Con A) or by coculture with phytohemagglutinin-activated autologous lymphoblasts induced CTL that killed autologous and heterologous CD4+lymphocytes, but not Con A–activated CD8+lymphocytes or Epstein-Barr virus (EBV)–transformed B lymphocytes. EBV did not stimulate such CTL in two subjects tested, although stimulation with Con A or autologous lymphoblasts induced CTL activity against CD4+lymphocytes in both subjects. CTL activity against autologous CD4+lymphocytes varied over time; killing of heterologous CD4+lymphocytes was often higher than that of autologous CD4+lymphocytes. HIV-infected individuals with Con A–inducible CTL against autologous CD4+lymphocytes lost more CD4+lymphocytes within 6 months of testing than HIV-infected individuals with no such CTL (p < .01). The mean (±SD) decrease in CD4+lymphocyte counts in a group of HIV-infected individuals with CTL activity against autologous CD4+lymphocytes was 121 ± 84, or 36%, of total CD4+lymphocytes over 6 months. In contrast, there was no significant change in mean CD4+lymphocyte count over 6 months in a group of HIV-infected individuals without CTL activity against autologous CD4+lymphocytes. In some HIV-infected individuals. CTL activity against autologous CD4+lymphocytes fell coincident with a drop in CD4+lymphocyte number in vivo. The same individuals maintained CTL activity against CD4+lymphocytes from an uninfected individual, consistent with elimination of autologous CD4+targets of CTL from the HIV-infected individuals in vivo. These results suggest that CTL against CD4+lymphocytes contribute to CD4+lymphocyte loss in HIV infection.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The objective of our study was to define the pharmacokinetics and pharmacodynamics of megestrol acetate in patients with human immunodeficiency virus (HIV) infection. A new suspension formulation of megestrol acetate (40 mg/ml) was administered as a single oral dose of 800 mg per day in an open label pharmacokinetic study for 21 days. On day 21 of therapy, patients were evaluated for changes in body weight and plasma samples were obtained for steady-state pharmacokinetic analysis. Ten HIV-infected men with an involuntary weight loss of >10% baseline were evaluated. A high degree of interpatient variability in megestrol acetate pharmacokinetics was observed, with an 8− and 5-fold range in the rate and extent of absorption, respectively. All patients reported an increase in appetite, and 8 of 10 patients gained weight by 3 weeks; the median change in weight in all patients at 3 weeks was a 1.8-kg gain (range: 2.3-kg loss to 6.4-kg gain). The two patients who did not gain weight had the lowest area under the curve (AUC), Cmax, and Cminvalues. A statistically significant correlation between the ratio of body weight at 3 weeks/initial weight (weight index) and the percentage of the 24-h dosing interval that megestrol acetate concentrations exceeded a 300-ng/ml threshold was observed. These data indicate variable levels of systemic exposure to drug following a fixed dose of a suspension formulation of megestrol acetate. Increase in weight during the early stages of megestrol acetate therapy is related to the extent of in vivo drug exposure above a threshold concentration. Dose individualization may be required for weight gain in AIDS with megestrol therapy.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Lipopolysaccharide (LPS) in the cell wall of theP. aeruginosais a major factor in the pathogenicity and virulence of this organism. Immunotype-specific serum antibodies to this LPS antigen (ALPS) are usually elevated with the onset of the bacteremia, act as opsonins, are protective in high levels, and are significantly associated with improved survival. In the present study, the ability of 11 patients with AIDS to mount a specific ALPS response with the onset ofP. aeruginosabacteria was evaluated prospectively. Of the 11 patients with AIDS only one had a substantial ALPS response, six mounted only a marginal ALPS response, and four had no ALPS response to the infecting strain of theP. aeruginosa.These data suggest most patients with AIDS do not exhibit a marked antigen-specific humoral response at the onset ofP. aeruginosabacteremia; this has important prognostic and therapeutic significance, as high ALPS titers are associated with survival.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

While recent studies indicate that injection drug users (IDUs) can change their behavior to reduce injection risk of HIV, it remains unclear which users are most likely to change and which mediating variables are most amenable to intervention. We report a study in which a cohort of high-risk IDUs was followed over time to determine which variables were associated with reduced injection risk of HIV. Of 317 IDUs who at baseline had shared a dirty needle in the previous 30 days, 234 (74%) were followed for 6 months. Of these, 107 (46%) reported reduced or eliminated injection risk between the baseline and follow-up interviews, 82 (35%) by not injecting and 25 (11%) by not sharing syringes. Those who attended self-help meetings between the two interviews were almost twice as likely to report reduced or eliminated risk as those who did not attend (OR= 1.92;p= 0.04). The findings suggest that, at least, IDUs in self-help groups comprise a population amenable to HIV interventions and, at most, that self-help groups may play an important role in reducing the risk of HIV in out-of-treatment populations.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Men with advanced human immunodeficiency virus (HIV) disease have a high prevalence of anal human papillomavirus (HPV) infection and potentially precancerous anal disease. To characterize prevalence of and risk factors for anal HPV infection and anal cytologic abnormalities, 37 HIV-positive and 28 HIV-negative participants in the San Francisco General Hospital Cohort Study were studied. A questionnaire was administered, followed by an anal examination consisting of two consecutive anal swabs for cytology and HPV DNA hybridization, and anoscopy with biopsy of visible lesions. Ten of 28 (36%) HIV-negative men and 19 of 37 (51%) HIV-positive men had anal HPV infection (p = 0.32). Risk factors for anal HPV infection included HIV positivity with a CD4 count <200/mm3(p = 0.03) and a history of smoking (p = 0.03). Abnormal anal cytology was found in 2 of 26 (8%) HIV-negative men and 10 of 36 (28%) HIV-positive men with cytology adequate for interpretation (p = 0.09). Risk factors for abnormal anal cytology included HIV positivity with a CD4 count <200/mm3(p = 0.006) and current smoking (p = 0.03). We conclude that the risk of development of anal disease and HPV infection was highest among HIV-positive men with a CD4 count of <200/mm3, and that smoking may play a role in the pathogenesis of anal disease.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The effects of human immunodeficiency virus type 1 (HIV-1) serostatus, AIDS, and level of immunosuppression on health service use were examined in the Multicenter AIDS Cohort Study. Data on self-reported hospitalizations, outpatient medical services (non–emergency room) and emergency room care during the preceding 6 months were collected for 3,447 homosexual/bisexual men returning for their 14th and/or 15th semiannual visits in Chicago, Baltimore, Los Angeles, and Pittsburgh. AIDS-free seropositive men with CD4+cells+cells were >500/μl. Dramatic increases in outpatient care for each level of immunosuppression were observed. HIV-1-related symptoms were associated with increased hospitalizations (OR = 4.8, 95% CL = 3.2, 7.3), use of outpatient medical services (OR = 3.3, 95% CL = 1.9, 5.6), and emergency room care (OR = 3.1, 95% CL = 2.1, 4.6). Persons with AIDS and ±50 CD4+cells/μl were most likely to be hospitalized (OR = 8.1: 95% CL = 4.4, 14.9). No significant difference (p > 0.05) in emergency room use was observed according to HIV-1 serostatus, AIDS, or immunosuppression, after adjusting for insurance and clinical symptoms. To the extent that CD4+cell counts are used as one of the criteria for an AIDS diagnosis and such a diagnosis broadens available benefits to persons with HIV disease, the pattern of health care services described here will be important for health care providers and planners.

ISSN:0894-9255    

出版商:OVID    

年代:1994

数据来源: OVID