CD80 AND CD86 COSTIMULATORY MOLECULES ON CIRCULATING T CELLS OF HIV INFECTED INDIVIDUALS

Abstract The expression of CD80 and CD86 costimulatory molecules, typical for antigen presenting cells (APC), was measured on circulating T cells of 20 HIV-infected individuals and of 11 HIV-negative healthy controls. The CD80 and CD86 molecules were present on both circulating T subsets of HIV-infected individuals (mean of CD80 expression within CD4 + T cells [CD80/CD4]: 5.0%; and CD86/CD4: 2.6%; CD80/CD8 4.1% and CD86/CD8: 2.7%) and were associated with HLA-DR expression. Some CD80 and CD86 expression was also found in normal controls, and only the expression of CD86 was significantly ( P + and CD8 + T cells of HIV-infected individuals. The expression of CD28 was decreased on T cells of HIV-infected individuals and was negatively correlated to the expression of HLA-DR and CD86 (mean CD28 within CD3 + T cells: HIV + 29.5%, HIV − 67.6%; correlation coefficient, −0.75 and −0.71, respectively). The more the disease proceeds, the less CD28 and the more DR and CD86 are found on circulating T cells. This suggests that during HIV infection T cells themselves develop an antigen presenting phenotype by upregulating expression of HLA-DR, CD86 and CD80 molecules.