Persistent expansion, in a human immunodeficiency virus-infected person, of Vβ-restricted CD4+CD8+ T lymphocytes that express cytotoxicity-associated molecules and are committed to produce interferon-γ and tumor necrosis factor-α

The present study describes the persistent expansion of a subpopulation of circulating double-positive CD4(+)CD8(+) T cells in a human immunodeficiency virus(HIV)-infected person over 8 years, The percentage of double-positive cells was remarkably stable with time and was not related to HIV plasma virus load. CD4(+)CD8(+) cells exhibited phenotypic characteristics of activated memory T lymphocytes. Analysis of V beta usage by the T cell receptors of these cells indicated restricted expression to the V beta 14 and V beta 17 families, Most CD4(+)CD8(+) cells constitutively expressed cytotoxicity-associated molecules (C1.7 and perforin) and were selectively committed to produce interferon-gamma and tumor necrosis factor-alpha, cytokines involved in cytotoxic function. The kinetics of changes in the relative proportion of single-positive CD4(+) and double-positive CD4(+)CD8(+) T cell subsets and a similar bias in V beta usage by these subsets suggest that CD4(+)CD8(+) lymphocytes originate from peripheral expansion of mature CD4(+) T cells.