HIV Responses May Lie in the Genes

People with a rare genetic makeup experience significantly slower HIV disease progression than those without the gene combination, researchers reported in the August 17 edition of Proceedings of the National Academy of Sciences. The scientists studied 84 patients in the Swiss-Spanish Intermittent Therapy Trial to examine the role of HLA type-1 molecules on the surface of immune system cells in prompting a killer T-cell response to invading pathogens. HIV-positive study subjects with a rare genetic makeup giving them an especially broad and unusual array of HLA molecules were shown to have immune systems better able to recognize a wider variety of HIV peptides and launch killer T-cell attacks on the virus than those with commonly occurring HLA types. The rarer the HLA types, the slower HIV disease progresses because the virus is less likely to have mutated defenses that prevent it from being recognized and subsequently destroyed, the researchers say.