Defective T cell colony formation and IL-2 receptor expression in HIV-infected homosexuals: relationship between functional abnormalities and CD4 cell numbers.
HIV infection is known to induce a progressive T helper/inducer (CD4) lymphopenia and to impair the functional activities of residual cells. The present studies examined the relationship between the CD4 cell count and three functional assays: T cell colony formation in semisolid media, the capacity of PHA-stimulated cells to express IL-2 receptors, and their ability to synthesize and secrete IL-2. Cells from antibody-positive homosexuals with normal numbers of CD4 cells (greater than 700/microliters) showed defective reactivity in two assays, colony growth, and IL-2 receptor expression. These defects became progressively more pronounced in homosexuals with moderate (400-700 cells/microliters) and severe (less than 400/microliters) reductions in assays for IL-2 production by PHA-stimulated lymphocytes. Mixing experiments suggest that cells from HIV-infected men nonspecifically inhibit the colony growth of normal cells; this abnormality could be reversed by addition of exogenous IL-2. These data suggest that defective colony growth and reduced IL-2 expression are functional abnormalities directly resulting from HIV infection. Furthermore, these changes can precede the CD4 lymphopenia induced by this viral infection.
Winkelstein
A
A
Department of Medicine, Montefiore Hospital, University of Pittsburgh, School of Medicine, PA 15213.
Kingsley
L A
LA
Weaver
L D
LD
Machen
L L
LL
D000911:Antibodies, Monoclonal; D015483:HIV Antibodies / Q000032:analysis; D006679:HIV Seropositivity / Q000276:immunology*; D006716:Homosexuality; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D006377:T-Lymphocytes, Helper-Inducer / Q000473:pathology*
D000911:Antibodies, Monoclonal; D015483:HIV Antibodies; D007376:Interleukin-2; D015375:Receptors, Interleukin-2