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Biomedical subjects

S Wolinsky

Publications and source records attributed to S Wolinsky.

At least 19 recordsLinked to original sources

The Ariel Project: A prospective cohort study of maternal-child transmission of human immunodeficiency virus type 1 in the era of maternal antiretroviral therapy.

In a prospective cohort study, clinical and biologic factors that contribute to maternal-child transmission of human immunodeficiency virus type 1 (HIV-1) were studied. HIV-infected pregnant women and their infants were evaluated prospectively according to a standardized protocol. Of 204 evaluable women, 81% received zidovudine during their pregnancy. The infection rate among the 209 evaluable infants was 9.1%. By univariate analysis, histologic chorioamnionitis, prolonged rupture of membranes, and a history of genital warts were significantly associated with transmission. Additional factors associated with transmission that approached significance included a higher maternal virus load at delivery and the presence of cocaine in the urine. In a logistic regression model, histologic chorioamnionitis was the only independent predictor of transmission. Despite a significantly higher transmission rate at one site, no unique viral genotype was found at any site. Thus, chorioamnionitis was found to be the major risk factor for transmission among women receiving zidovudine.

Acquired Immunodeficiency Syndrome

Lack of strong immune selection pressure by the immunodominant, HLA-A*0201-restricted cytotoxic T lymphocyte response in chronic human immunodeficiency virus-1 infection.

Despite detailed analysis of the HIV-1-specific cytotoxic T lymphocyte response by various groups, its relation to viral load and viral sequence variation remains controversial. We analyzed HLA-A*0201 restricted cytotoxic T lymphocyte responses in 17 HIV-1-infected individuals with viral loads ranging from < 400 to 221,000 HIV RNA molecules per milliliter of plasma. In 13 out of 17 infected subjects, CTL responses against the SLYNTVATL epitope (p17 Gag; aa 77-85) were detectable, whereas two other HLA-A*0201 restricted epitopes (ILKEPVHGV, IV9; and VIYQYMDDL, VL9) were only recognized by six and five individuals out of 17 individuals tested, respectively. Naturally occurring variants of the SL9 epitope were tested for binding to HLA-A*0201 and for recognition by specific T cell clones generated from five individuals. Although these variants were widely recognized, they differed by up to 10,000-fold in terms of variant peptide concentrations required for lysis of target cells. A comparison of viral sequences derived from 10 HLA-A*0201-positive individuals to sequences obtained from 11 HLA-A*0201-negative individuals demonstrated only weak evidence for immune selective pressure and thus question the in vivo efficacy of immunodominant CTL responses present during chronic HIV-1 infection.

Acquired Immunodeficiency Syndrome

Genetic evaluation of suspected cases of transient HIV-1 infection of infants.

Detection of human immunodeficiency virus-type 1 (HIV-1) on only one or a few occasions in infants born to infected mothers has been interpreted to indicate that infection may be transient rather than persistent. Forty-two cases of suspected transient HIV-1 viremia among 1562 perinatally exposed seroreverting infants and one mother were reanalyzed. HIV-1 env sequences were not found in specimens from 20; in specimens from 6, somatic genetic analysis revealed that specimens were mistakenly attributed to an infant; and in specimens from 17, phylogenetic analysis failed to demonstrate the expected linkage between the infant's and the mother's virus. These findings argue that transient HIV-1 infection, if it exists, will only rarely be satisfactorily documented.

DNA, Viral

Overlapping epitopes in human immunodeficiency virus type 1 gp120 presented by HLA A, B, and C molecules: effects of viral variation on cytotoxic T-lymphocyte recognition.

Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL) are thought to exert immunologic selection pressure in infected persons, yet few data regarding the effects of this constraint on viral sequence variation in vivo, particularly in the highly variable Env protein, are available. In this study, CD8+ HIV type 1 (HIV-1) envelope-specific CTL clones specific for gp120 were isolated from peripheral blood mononuclear cells of four HIV-infected individuals, all of which recognized the same 25-amino-acid (aa) peptide (aa 371 to 395), which is partially contained in the CD4-binding domain of HIV-1 gp120. Fine mapping studies revealed that two of the clones optimally recognized the 9-aa sequence 375 to 383 (SFNCGGEFF), while the two other clones optimally recognized the epitope contained in the overlapping 9-aa sequence 376 to 384 (FNCGGEFFY). Lysis of target cells by the two clones recognizing aa 375 to 383 was restricted by HLA B15 and Cw4, respectively, whereas both clones recognizing aa 376 to 384 were restricted by HLA A29. Sequence variation, relative to the IIIB strain sequence used to identify CTL clones, was observed in autologous viruses in the epitope-containing region in all four subjects. However, poorly recognized autologous sequence variants were predominantly seen for the A29-restricted clones, whereas the clones specific for SFNCGGEFF continued to recognize the predominant autologous sequences. These results suggest that the HLA profile of an individual may not only be important in determining the specificity of CTL recognition but may also affect the ability to recognize virus variants and suppress escape from CTL recognition. These results also identify overlapping viral CTL epitopes which can be presented by HLA A, B, and C molecules.

Cytotoxicity, Immunologic

Quantitation of human immunodeficiency virus type 1 DNA and RNA by a novel internally controlled PCR assay.

A novel internally controlled PCR (ICPCR) assay was developed to accurately quantitate human immunodeficiency virus type 1 (HIV-1) DNA and RNA in peripheral blood mononuclear cells and plasma. The ICPCR assay was sensitive and reproducible within a linear range of amplification of 10(0) to 10(3) copies for HIV-1 DNA and 10(1) to 10(4) copies for HIV-1 RNA. The assay detected HIV-1 RNA in plasma and peripheral blood mononuclear cells from all HIV-1 subjects regardless of disease stage. ICPCR was compared with a branched-DNA signal amplification assay for subjects beginning antiretroviral therapy. The reductions in plasma HIV-1 RNA in response to therapy were comparable with the two assays. The ICPCR assay should be useful in monitoring HIV-1 RNA levels both in natural history studies and in clinical trials of antiretroviral agents.

DNA, Viral

Evidence for coinfection by multiple strains of human immunodeficiency virus type 1 subtype B in an acute seroconvertor.

Sequences encoding the envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) were amplified by PCR from plasma and peripheral blood mononuclear cells obtained at four time points from an acute seroconvertor. Genetic analyses, including nucleotide sequencing and heteroduplex mobility studies, showed that the patient harbored three distinct populations of HIV-1 clade B envelope sequences, with nucleotide distances ranging from 9.2 to 17.2%. One population of sequences was clearly distinguishable from the others on the basis of phylogenetic analysis. In addition, sequences suggesting recombination between two of the three distinct viral populations were also found. This case of acute seroconversion provides clear and conclusive evidence that coinfection by multiple HIV-1 strains can indeed occur in vivo.

Acquired Immunodeficiency Syndrome

Analysis of human immunodeficiency virus-infected tissues by amplification and in situ hybridization reveals latent and permissive infections at single-cell resolution.

Latent and productive viral infections are at the extremes of the spectrum of virus-cell interactions that are thought to play a major role in the ability of such important human pathogens as human immunodeficiency virus (HIV) to elude host defenses and cause disease. The recent development of PCR-based methods to amplify target sequences in individual cells in routinely fixed tissues affords opportunities to directly examine the subtle and covert virus-cell relationships at the latent end of the spectrum that are inaccessible to analysis by conventional in situ hybridization techniques. We have now used PCR in situ with in situ hybridization to document latent and permissive HIV infection in routinely fixed and paraffin-embedded tissue. In one of the first specimens we examined, a tumor biopsy from an HIV-infected individual, we found many of the lymphocytes and lymphocytes infiltrating the tumor had HIV DNA that was detectable only by PCR in situ. The fraction of positive cells varied regionally, but there were foci where most of the cells contained HIV DNA. Most of these lymphocytes and macrophages are latently infected, as we could detect HIV RNA in fewer than one in a thousand of these cells. We also detected HIV RNA, surprisingly, in 6% of the tumor cells, where the number of copies of viral RNA per cell was equivalent to productively infected cell lines. The alternative states of HIV-gene expression and high local concentration of latently infected lymphocytes and monocytes revealed by these studies conceptually supports models of lentiviral pathogenesis that attribute persistence to the reservoir of latently infected cells and disease to the consequences of viral-gene expression in this population. The magnitude of infection of lymphocytes documented in this report is also consistent with the emerging view that HIV infection per se could contribute substantially to depletion of immune cells in AIDS.

Adenocarcinoma

Diagnosis of infection with the human immunodeficiency virus.

The development and subsequent widespread use of accurate, sensitive, and relatively inexpensive diagnostic tests for infection with the human immunodeficiency virus (HIV) have been critically important in mapping the spread of the virus and managing HIV-infected individuals. Although the ELISA (for screening) and western blot (confirmatory test) techniques have, for the most part, fulfilled these criteria, interpretation of results of these tests is not always as straightforward as would be ideal. For example, what is the significance of an indeterminate western blot? How many times should the test be repeated? When can the patient be told he/she is truly HIV antibody negative? In this AIDS Commentary, Drs. John P. Phair and Steven Wolinsky of the Department of Medicine at Northwestern University Medical School address these questions and present their thoughts on these timely and extremely important issues.

Blotting, Western

Low prevalence of HIV in high-risk seronegative homosexual men evidenced by virus culture and polymerase chain reaction.

OBJECTIVE: To assess the presence of covert HIV-1 infection. SETTING: High-risk seronegative homosexual men from the Pittsburgh portion of the Multicenter AIDS Cohort Study were examined for the presence of HIV-1 infection. PATIENTS, PARTICIPANTS: Ten men (group 1) were examined prospectively for the presence of HIV-1 in their freshly-obtained peripheral blood mononuclear cells (PBMC). Furthermore, cryopreserved PBMC from 26 men (group 2) at their first visit (1984-1985) were examined retrospectively for the presence of HIV-1. MAIN OUTCOME MEASURES: PBMC samples from groups 1 and 2 were examined for HIV-1 by polymerase chain reaction (PCR) using gag, env and strong-stop (long terminal repeat) specific primers. In addition, fresh PBMC samples from group 1 were examined for HIV-1 by virus culture. RESULTS: None of the 10 PBMC samples from group 1 were positive for virus culture and PCR. Only one of the 26 men from group 2 was positive for gag and strong-stop DNA sequences. This PCR-positive, seronegative subject was found to be negative for HIV-1 by PCR at follow-up visits up to 48 months later. None of 15 seronegative, low-risk homosexual men and 12 seronegative heterosexual men were found to be PCR-positive for HIV-1. However, six HIV-1-seropositive men were positive by PCR for gag, env, and strong-stop HIV-1 DNA sequences. CONCLUSIONS: These results suggest a low prevalence of covert HIV-1 infection in high-risk seronegative homosexual men in our geographic area.

Adult

The small lentiginous nevus.

Eighteen small lentiginous nevi, each 1-3 mm in diameter, showed aggregates (nests) of melanocytes in the lower portion of the epidermis. In six of the 18 nevi, nests of melanocytes were evident only after examination of numerous serial sections (approximately 100-125). These six lesions would have been diagnosed as simple "lentigines" if the serial sections had not been examined. Lesions referred to as simple "lentigines" may actually be lentiginous nevi.

Epidermis

Analysis of dendritic cells in solitary angiofibromas for factor VIII.

We studied dendritic cells in the dermis of six angiofibromas by the peroxidase-antiperoxidase method in order to determine whether they are endothelial cells. The primary antiserum used was directed to factor VIII, an endothelial cell marker. The dendritic cells were not immunoreactive for factor VIII, suggesting that they are not endothelial cells.

Cytoplasm