Human Mhc Diversity and the Molecular Epidemiology of Hiv-1 in Southeast Asia

HIV-1 is one of the most genetically variable viruses ever encountered. However, as described in SE Asia, the inter-clade genetic diversity of HIV-I may be relatively conserved at the population level. This relative lack of diversity may partially be attributed to the maturity of the epidemic in the region, however social and genetic factors may be operative. This is suggested by the continued dominance of clade E throughout the Greater Mekong Subregion since the simultaneous introduction of subtypes B and E (actually a circulating recombinant form, or CRF, of subtypes A and E) in Thailand. The extensive genetic polymorphism of human MHC (or HLA) may play an important role in shaping the molecular epidemiology of HIV-1. Studies have consistently demonstrated the association of HLA-B*57 and related alleles of the B58 supertype with susceptibility to, and progression of HIV-1 infection among Africans and Caucasians, possibly driven by cytotoxic T-cell activity. Similarly, HLA-A*11, common among ethnic Thais, has been associated with reduced susceptibility to infection. Thus, HLA class I molecules may be 'imprinting' mutations associated with strong immune responses at a population level. The purpose of this presentation/poster will be to describe the parallel diversity of HIV-1 and polymorphism of human MHC, and its significance for the development of an HIV-1 vaccine.