Study Details

Protocol Status:
Study Purpose:

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.

Study Design:

Observational cohort study.

Study Population:

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.

Study Size:

100 HIV-1 infected individuals and 25 HIV-uninvected controls.

Study Duration:

Enrollment will take 6-12 months; participants will be followed for up to 12 months.

Treatment Regimen:

None, this is an observational study.

Primary Objectives:

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.

Secondary Objectives:

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.

Key Study Personnel

Personnel list available upon request.

Study Sites List