Cytotoxic T-lymphocytes will be a primary effector in any successful HIV-1 vaccine. Knowledge of the protective CTL epitopes and their cross-subtype effectiveness is incomplete. The study proposes to use the setting of natural infection in individuals multiply exposed to HIV subtypes A, C, and D to gain understanding of a protective CTL response. From a high-risk cohort in Tanzania 3 groups will be identified: persistently seronegative, persistently infected with a single HIV subtype or recombinant, and super infected with a second subtype. CTL ELISPOT and epitope mapping, viral load and diversity, HLA typing, and MHA, a new sub-typing tool, will be employed. This study will be the first to define the CTL response capable of protecting from new HIV infections in persistent seronegatives and, in the same population and setting, to identify the flawed CTL responses that permit super infection of already infected individuals.
Funding SchemeCSC - Cost-sharing contracts
7925 Observatory, Cape Town