Journal of acquired immune deficiency syndromes最新文献

We investigated the ability of human recombinant interleukin-7 (IL-7) to enhance the immune responses of mice vaccinated with either the alum-associated or liposome-formulated recombinant human immunodeficiency virus (HIV)-envelope protein, env-2-3SF2 (a nonglycosylated denatured gp 120 of HIV-1SF2 produced in genetically engineered yeast). Pathogen-free (C3H) mice were vaccinated on days 0, 14, and 28 with 10 micrograms of either the alum-associated env-2-3SF2 or liposome-formulated env-2-3SF2, both containing a lipophylic muramyl tripeptide, MTP-PE. Liposome-formulated IL-7 (5 micrograms/mouse) or empty liposomes were given on days 7, 14, 21, and 28. Antibody response against the immunized antigen, evaluated on day 21 and day 35 or 42, showed that liposome-formulated antigen induced higher antibody titer than did alum-associated antigen, and these antibody responses can be enhanced by concurrent administration of IL-7 liposomes. Spleen cells were harvested on day 21 and day 35 or 42 to evaluate cytotoxic T lymphocyte responses directed against autologous cells infected with vaccinia virus-expressing HIV-envelope protein. Mice treated with liposome-formulated antigen expressed the highest cytotoxic t-lymphocyte (CTL) activity, regardless of whether IL-7 liposome was given as an immune potentiator. In contrast, spleen cells from mice vaccinated with alum-associated antigen exhibited minimal CTL response, which was enhanced by concurrent IL-7 liposome treatment. Collectively, IL-7 liposome treatment enhanced the antibody production of the alum-associated or liposome-formulated env-2-3SF2, whereas its enhancement of CTL activity was detected only in mice vaccinated with alum-associated antigen.

The variable rate of disease progression in HIV-1-infected patients treated with zidovudine may be related to certain viral characteristics, such as, antiviral drug resistance, virus burden, and viral syncytium-inducing (SI) capacity. Thirty-two HIV-1-infected patients treated with zidovudine (mean of 34 months) were studied to determine the relationship of SI phenotype and the codon 215 pol gene mutation (a marker of zidovudine resistance) to virus burden and CD4 cell decline. Patients with SI strains and the codon 215 mutation in their proviral DNA had a 54% decline in CD4 cells and a virus burden of 21,480 proviral DNA copies/10(6) CD4 cells. In contrast, patients with non-SI (NSI) strains and wild-type at codon 215 had a 10% increase in CD4 cells and had a viral burden 1/46 that of patients with SI and the 215 mutation. Among patients with NSI strains, changes in CD4 cells depended on the presence of the codon 215 mutation (-160 CD4 cells/microliters), compared with those wild-type at codon 215 (+28 CD4 cells/microliters) (p < 0.01). There was a concordant rise in virus burden between proviral DNA and plasma HIV RNA depending on HIV phenotype and genotype. Using multiple linear regression, SI phenotype and the codon 215 mutation were found to independently predict CD4 cell decline and increased virus burden in zidovudine-treated patients.

The env gene of the human immunodeficiency virus-type 1 (HIV-1) was transfected in CEM-nkr, a human lymphoid cell line of T lineage that is resistant to the activity of natural killer cells, and for the first time, transfected T cell clones were established that stably express gp160 intracellularly and gp120 on the surface as demonstrated by radioimmunoprecipitation as well as by indirect membrane immunofluorescence. The regulatory protein vpu was not detected by radioimmunoprecipitation in these clones. The surface expression of gp120 without vpu in these clones provides direct evidence that gp160 is processed and cleaved (without vpu) in CD4+ cells. The CD4 antigens of these cells coprecipitated gp160; interestingly, no reduction of the surface CD4 expression (detectable by flow cytometric analysis of membrane immunofluorescence with OKT4) in the transfected cells was observed. However, decreased reactivity of the transfected clones with OKT4A was observed. The gp120-expressing cells did not form syncytia on coculture with other CD4+ human cell lines. These observations suggest the binding of gp120 to the surface CD4 antigen of the transfected cells. The transfected cells retained their resistance to the activity of the natural killer cells but showed a significant (p < 0.05) lysis when they were preincubated with AIDS patients' serum containing anti-gp120/41 antibodies. Thus, the expressed gp120/41 in these cells made them susceptible to killing by an antibody-dependent cellular cytotoxicity (ADCC) mechanism. To our knowledge, these are the first reported CD4+ T cell lines that stably express HIV envelope proteins. These cell lines would be useful as targets in exploring gp120/41-specific immune responses, especially in conducting gp120/41-specific ADCC studies in HIV-infected or gp120/41 (gp160)-vaccinated individuals.

The significance of detection of human immunodeficiency virus (HIV) DNA by the polymerase chain reaction (PCR) in seronegative or seroconverting (SC) subjects remains controversial. In a previously reported study, we identified a case in which a specimen collected 12 months before seroconversion (pre-SC) was found repeatedly to be PCR positive in three experienced laboratories, while the 6-month pre-SC bleed was PCR-negative; PCR-based human leukocyte antigen (HLA)-DQA and -DRB typing of serial peripheral blood mononuclear cell (PBMC) samples from this case did not indicate a specimen mix-up or labeling error. To further investigate this case, we used HIV env sequence and DNA heteroduplex gel-shift analyses to characterize HIV quasispecies present in serial pre- and post-SC specimens. HIV env sequences and gel-shift pattern analyses from the 12-month pre-SC versus post-SC samples indicated that markedly distinct quasispecies were present, suggesting possible abortive infection followed by reinfection and subsequent seroconversion. However, the HIV burden of this pre-SC sample was very low (1 provirus/10(6) PBMCs), and the quasispecies was highly heterogeneous, findings suggesting long-term rather than recent HIV infection. To test the hypothesis that the index pre-SC sample was PCR positive owing to trace blood contamination during initial processing, we analyzed the three seropositive samples collected on the same date in 1985. One of these samples was highly related to the index pre-SC sample by env sequence and gel-shift methodologies.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous measurements of phenotypically defined memory CD4+ cells and in vitro proliferation to three recall antigens (Ags; tetanus toxoid, influenza, and Candida albicans) were performed in 53 HIV-seropositive subjects and 39 HIV-seronegative controls. The results indicate that the low proliferative responses to recall Ags of those who were HIV infected could be partly, but not fully, explained by a decrease of phenotypically defined memory CD4+ cells. This is, to our knowledge, the first report of experiments that simultaneously measured memory CD4+ cell numbers and function and then examined whether the low responses observed in seropositive subjects could be explained by low numbers of phenotypically defined memory CD4+ cells. A central finding of the study, which argues against prevailing dogma, was that within the CD4+ lymphocyte population, the proportion of cells displaying the memory phenotype was not selectively decreased in HIV-seropositive subjects as compared with the proportion of these cells in seronegative homosexual controls. An entirely new finding of the study was that AIDS patients, many of whom were unresponsive to all three recall Ags tested, actually had a significant increase in the proportion of CD4+ cells with the memory phenotype, and this fraction approached 100% in subjects with CD4+ cell numbers that were near zero. A final observation of the study, possible because some patients were on zidovudine (ZDV), was that there was no evidence that ZDV treatment led to an increased proliferative response to recall Ags in vivo. An in vitro study also found no effect of ZDV, dideoxycytidine (ddC), or azido-dideoxyuridine (AZU) on proliferative responses to recall Ags.

To examine the effects of Mycobacterium tuberculosis on human immunodeficiency virus type 1 (HIV-1) expression, the monocytoid cell line U1 containing integrated provirus was incubated with the H37Ra strain of M. tuberculosis. This resulted in heightened expression of virus in supernatant that was partially inhibited by antibody to tumor necrosis factor-alpha (TNF-alpha). Purified protein derivative (PPD) prepared from M. tuberculosis also could activate HIV expression, and this was less affected by anti-TNF antibody. PPD could activate the HIV promoter in both U937, the monocytoid cell line from which U1 was derived, and Jurkat, a CD4+ lymphoid line. Activation was abolished by mutations in the nuclear factor (NF)-kB binding domains. Jurkat cells transfected with a plasmid construct linking 8 NF-kB binding domains to the chloramphenicol acetyltransferase (CAT) gene showed increased activity of the reporter gene after activation with PPD. Transcriptional activation of HIV expression by mycobacteria and mycobacterial products may enhance propagation of HIV in monocytoid and lymphoid cells. This may result in accelerated HIV disease progression in persons coinfected with M. tuberculosis.

Objectives were to measure syringe cleaning strategies used by injection drug users (IDUs) and to assess syringe contact with bleach during cleaning demonstrations. IDUs were interviewed about cleaning activities during their most recent injection episode; they demonstrated these activities on videotape. Coders reviewed the videotapes, categorized activities, and used stop watches to record bleach exposure. Of 161, 146 subjects reported cleaning at last injection, 85 (58%) of 146 used full strength bleach. Of bleach users, 20% had total contact time (duration of bleach inside syringe) of > or = 30 s; combining draw (time taken to fill syringe) and contact times, 54% of bleach users had total "flush" times of > or = 30 s. Median observed time per bleach flush was 16 s. Median reported cleaning times were twice as long as observed. Recent reports indicate 30 s of exposure to undiluted bleach is necessary to inactivate HIV in the laboratory; here, 80% of IDUs using bleach had contact of < 30 s. Judgment of contact time was inaccurate. On average, instructions advocating two bleach flushes may reach 30 s; here, half the subjects had insufficient time with two flushes. The majority showed inadequate techniques, therefore, alternate cleaning strategies should be developed.

Bleach cleansing of injection equipment has been recommended to reduce the risk of human immunodeficiency virus (HIV) transmission associated with the reuse of injection equipment by injecting drug users (IDUs). We evaluated the recall and performance of the most commonly recommended bleach cleansing procedure of two complete fillings of the syringe with bleach, followed by two complete fillings with rinse water, and not putting used bleach and water back into source containers. IDUs were taught this procedure on enrollment in an HIV prevention demonstration project in Dade County, Florida. During follow-up session 6-12 months after initial training, the knowledge and ability of IDUs to perform bleach cleansing were assessed by trained observers using a standardized method. In 1988-90, we assessed the knowledge and ability of 450 IDUs to perform the bleach cleansing procedure taught at enrollment. More than 90% of IDUs assessed performed the basic steps. However, only 43.1% completely filled the syringe with bleach and only 35.8% completely filled the syringe with bleach at least twice. Substantial proportions of IDUs did not perform all the steps of the previously taught bleach cleansing procedure. Compliance decreased as the number of steps required was increased. This limited compliance may make bleach cleansing less effective and suggests that some IDUs may fail to adequately disinfect injection equipment and therefore sterile needles and syringes are safer than bleach-cleansed ones. Compliance testing can help assess the effectiveness of HIV prevention programs.

Using lookback procedures and other methods, we identified and then prospectively followed human immunodeficiency virus type 1 (HIV-1)-infected transfusion recipients and their sex partners to determine AIDS incidence and risks of heterosexual transmission of HIV-1. At enrollment, 7 of 32 (21.9%) female partners of male recipients were themselves infected with HIV-1, as compared with none of 14 male partners of female recipients (p = 0.08). No additional episodes of transmission were observed. The prevalence of advanced immunodeficiency at enrollment was similar in male and female recipients. Male recipients with advanced immunodeficiency (CD4+ lymphocyte count < or = 0.20 x 10(9)/L or a history of clinical AIDS) at enrollment were more likely to have infected their female partners (odds ratio = 7.9; p = 0.03) than men with neither condition. Similarly, AIDS-free survival, as estimated by the product-limit method, was lower among male transmitters than among male nontransmitters (p = 0.01). Transmission was not associated with frequency of unprotected vaginal intercourse. Our data suggest that HIV-1-infected men who develop immunodeficiency rapidly are more likely to infect their sex partners and that the greater efficiency of male-to-female HIV-1 transmission is not explained by a greater number of sexual contacts or more advanced immunodeficiency in index subjects.

Infection with the human immunodeficiency virus type 1 (HIV-1) in man is associated with an increase in the incidence of Kaposi's sarcoma (KS). The biological and clinical characteristics of these patients differ from those of subjects with other HIV-associated diseases. Here we report that levels of serum-soluble intercellular adhesion molecule 1 (sICAM 1) are increased in HIV-1-positive patients with KS, but not in patients belonging to other CDC classification groups. KS patients with elevated levels of serum sICAM 1 had a significant lowering of CD4 cell counts during the follow-up period compared with those KS subjects whose sICAM 1 levels were only moderately higher. We suggest that increased sICAM 1 levels may have a pathogenetic role in the development of HIV-associated immunodeficiency in KS patients and may also be considered an important prognostic factor.