Study Details
To study recent HIV-1 infection by measuring viral load and CD4 counts, characterizing viral isolates and analyzing the humoral and cellular immune responses to subtype C HIV-1 infection and to analyze immune responses in relationship to HLA alleles and haplotypes in Southern African populations that are likely to participate in future vaccine trials.
Observational cohort study.
100 HIV-1 infected individuals (20 from each of the five southern African HIVNET sites) and 25 HIV-uninfected controls (5 from each site) will be identified prospectively from existing HIVNET and non-HIVNET trials or observational cohorts or by using “detuned” serologic testing of prevalent infections.
100 HIV-1 infected individuals and 25 HIV-uninvected controls.
Enrollment will take 6-12 months; participants will be followed for up to 12 months.
None, this is an observational study.
To characterize HIV-1 variants from the southern African HIVNET sites to assess the conservation of known and newly identified CTL epitopes.
To determine the extent of intra- and inter-subtype cross-reactivity of CTL responses elicited by HIV-1 variants circulating in southern Africa.
To further characterize the distribution of HLA genotypes in HIV-1 infected and uninfected individuals from southern Africa.
To map CTL epitopes restricted by local HLA types in order to identify epitope-rich regions and/or immunodominant CTL responses.
To measure the ability of antibodies from HIV-1 infected individuals to neutralize subtype C isolates within and between the southern African sites to identify the breadth of cross-neutralization within the C subtype.
To establish the Southern Africa Regional CTL Laboratory in order to support these studies and future phase I, II and III vaccine trials.
To evaluate the relationship between conventional 51Cr-release CTL assays and alternative assays, such as ELISpot, intracytoplasmic cytokines and peptide/MHC tetramer complexes.
To determine if cryopreserved PBMC from HIV-1 infected participants can be used in functional killing assays and alternative methods for measuring CTL.
To determine the relationship between immune responses in the first 6-9 months of infection with predictors of disease progression.