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The initial site of exposure to human immunodeficiency virus (HIV)-1 during heterosexual transmission occurs in the genital tract. Although the majority of immunological studies have focused on the immune response to HIV-1 at the systemic level, our understanding of tissue-specific immunity is deficient. The goal of the present study was to characterize T cell populations found in the cervix of women shown to be resistant to infection by HIV-1. Levels of both systemic and cervical mucosal lymphocytes were compared between HIV-1-resistant, HIV-1-uninfected, and HIV-1-infected commercial sex workers (CSWs) as well as HIV-1-uninfected non-CSW control subjects at low risk for exposure. The HIV-1-resistant CSWs had increased cervical CD4+ and CD8+ T cell counts, compared with the HIV-1-uninfected CSWs; importantly, these increases were not reflected in the systemic lymphocyte compartment. There was a 2-fold increase in CD4+ T cell counts in the HIV-1-resistant CSWs, compared with both the HIV-1-infected and the HIV-1-uninfected CSWs. Expression of the HIV-1 coreceptors CCR5 and CXCR4 was also determined, and cytokine and beta chemokine levels in the genital mucosa were assessed. The HIV-1-resistant CSWs had a 10-fold increase in RANTES expression, compared with the HIV-1-uninfected CSWs. This is the first study to show elevated levels of beta chemokines and CD4+ T cells in the genital tracts of women who are exposed to HIV-1 and yet are uninfected. [ABSTRACT FROM AUTHOR]

Focuses on a study which determined the influence of human lymphocyte antigen supertype A2/6802 on HIV type 1 transmission in HIV positive mothers and children in Kenya. Methods; Results; Discussion.

Examines the effect of human immunodeficiency virus (HIV) type 1 viral genotype on mother-to-child transmission of HIV-1. Distribution of the HIV-1 clades among different transmitting groups of mothers in Nairobi, Kenya; Identification of recombinant, mixed and clade B isolates in Nairobi; Factors known to be associated with mother-to-child HIV transmission.

Mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) is a significant problem in countries with endemic HIV-1 infection. Between 1986 and 1991, 365 children of HIV-L-infected mothers and 363 control children were studied in Kenya. The overall risk of transmission from mother to child, determined by serologic evidence of infection by age ⩽5? 12 months and excess mortality in the HIV-I-exposed group, was 42.8% (range, 27.6%-62.2%). Marriage was the only maternal characteristic associated with transmission (odds ratio, 2.2; 95% confidence interval, 1.2–4.2; P < .05). Children who experienced growth failure were more likely to be infected. In 44% of children ultimately infected, the pattern of antibody response implied intrapartum or postnatal exposure to HIV-1. Of potential postnatal exposures examined, duration of breast-feeding beyond age 15 months and the mother being married were independently associated with increased risk of infection and seroconversion of children. The percentage of HIV infection attributable to breast-feeding ⩽5? 15 months was 32%. The frequency of mother-to-child transmission of HIV-I was high; a substantial proportion of infection occurred postnatally, possibly through breast-feeding. [ABSTRACT FROM PUBLISHER]