AEGiS-13IAC: Cytoxic T-Lymphocyte (CTL) activity in HIV exposed uninfected (EU) Zambians.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

Cytoxic T-Lymphocyte (CTL) activity in HIV exposed uninfected (EU) Zambians.

Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. WeOrA596)

Garba ML, Musonda R, Allen S, Frelinger S
M.L. Garba, University of North Carolina, CB 7290 804 Mejb, AT Chapel Hill, Chapel Hill NC 27599-7290, United States, Tel.: +1 919 966 2605, Fax: +1 919 962 8103, E-mail: mlgarba@med.unc.edu

BACKGROUND: Previous studies in repeatedly exposed uninfected (EU) Gambian and Kenyan Commercial Sex Workers (CSW's) showed the presence of HIV-specific CTLs in 6/15 (Kenya) to 5/6 (Gambia) of these women following repeated testing. This suggests a role for CTL's in resistance to HIV infection. In this study, we looked at a different class of high risk EU's belonging to a cohort of couples in which one partner is HIV infected and the other persistently seronegative despite active sexual practices. These subjects (not CSWs) are more representative of the normal, general population and the understanding of the role of CTL's in protection against HIV in this group will help in planning and monitoring HIV vaccine aimed at the general population.

METHODS: We studied thirty-seven EU's, 15 HIV positive and 8 low risk individuals from Lusaka, Zambia. CTL activity was determined using chromium release assay. The effectors for each subject are positively selected CD8 CTL's following a week of stimulation of T cells with Vaccinia virus encoding Clade-C Gag, Envelope and Polymerase genes. The targets were autologous B-cell lines infected by the same virus overnight. Vaccinia virus encoding Psc11 genes was used as a control virus.

RESULTS: HIV specific CTL's were found in 7/37 (18.5%) of the EU's, 12/15 (80%) of the HIV positive subjects and 0/8 (0%) of the low risk seronegative individuals. Multivariate logistic regression found no significant relationship between CTL results in both EU's and HIV positives and: gender, age, number of pregnancies, whether currently pregnant, stage of HIV disease, or log viral load.

CONCLUSIONS: CTL activities exist in a subset of exposed uninfected partners of HIV positive persons, and may play a role in the resistance of these individuals to HIV infection.

Keywords: AEGIS, HIV, HIV Infections, T-Lymphocytes, HIV Seropositivity, Prostitution, T-Lymphocytes, Cytotoxic, HIV Antigens, HIV Seronegativity, Viral Load, HIV Antibodies, HIV Core Protein p24, T-Lymphocytes, Helper-Inducer, Gambia, Kenya, Zambia, Human, Female, Pregnancy, immunology
000709
WeOrA596