PERSISTENT EXPANSION, IN A HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PERSON, OF V-BETA-RESTRICTED CD4(-LYMPHOCYTES THAT EXPRESS CYTOTOXICITY-ASSOCIATED MOLECULES AND ARE COMMITTED TO PRODUCE INTERFERON-GAMMA AND TUMOR-NECROSIS-FACTOR-ALPHA()CD8(+) T)

The present study describes the persistent expansion of a subpopulatio n of circulating double-positive CD4(+)CD8(+) T cells in a human immun odeficiency virus(HIV)-infected person over 8 years, The percentage of double-positive cells was remarkably stable with time and was not rel ated 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 exp ression to the V beta 14 and V beta 17 families, Most CD4(+)CD8(+) cel ls constitutively expressed cytotoxicity-associated molecules (C1.7 an d perforin) and were selectively committed to produce interferon-gamma and tumor necrosis factor-alpha, cytokines involved in cytotoxic func tion. The kinetics of changes in the relative proportion of single-pos itive CD4(+) and double-positive CD4(+)CD8(+) T cell subsets and a sim ilar bias in V beta usage by these subsets suggest that CD4(+)CD8(+) l ymphocytes originate from peripheral expansion of mature CD4(+) T cell s.