Role of CD8+ T Cells in the Selection of HIV-1 Immune Escape Mutations

Human immunodeficiency virus type-1 (HIV-1) infection represents one of the biggest public health problems worldwide. The immune response, mainly the effector mechanisms mediated by CD8(+) T cells, induces the selection of mutations that allows the virus to escape the immune control. These mutations are generally selected within CD8(+) T cell epitopes restricted to human leukocyte antigen class I (HLA-I), leading to a decrease in the presentation and recognition of the epitope, decreasing the activation of CD8(+) T cells. However, these mutations may also affect cellular processing of the peptide or recognition by the T cell receptor. Escape mutations often carry a negative impact in viral fitness that is partially or totally compensated by the selection of compensatory mutations. The selection of either escape mutations or compensatory mutations may negatively affect the course of the infection. In addition, these mutations are a major barrier for the development of new therapeutic strategies focused on the induction of specific CD8(+) T cell responses.