Immune and viral determinants of viral control or lack of control in HIV-1 subtype C chronically infected individuals possessing protective human leukocyte antigen class I alleles.

Kegakilwe Catherine Koofhethile, Professor Thumbi Ndung’u


Understanding fully which factors are responsible for the effective control of human immunodeficiency virus (HIV) replication will be beneficial in the design and evaluation of an effective HIV vaccine. Immunological factors, host and viral genetic factors may account for the differences in the course of disease progression. It is not fully understood as to why certain individuals are able to control viral replication over a long period of time. Previous work has linked the control of viraemia to many host and viral factors including the expression of certain human leukocyte antigen (HLA) class I alleles termed ‘protective alleles’, strong immune pressure on the virus that selects conserved targets of the virus and selection of immune escape mutations that are associated with viral fitness cost.  Although individuals with protective alleles are overrepresented among elite and viremic HIV controllers, loss of viral control and disease progression is also encountered among these individuals and the exact events that lead to this loss of control have not been fully described. We aim to study a group of individuals who possess protective alleles in an attempt to explain the mechanisms associated with viral load control in these individuals.