context: BACKGROUND: Recently, diminished @entity379 ( @entity379 ) and increased interleukin ( @entity3646 production in peripheral blood mononuclear cells (PBMCs) from @entity1097 @entity1 have been described by several groups, measured as total cytokine content in culture supernatants. These studies suggested a predominance of TH2-like cells producing large amounts of @entity3646 in @entity1097 @entity1 . It is not clear whether the reported cytokine imbalances are the result of an alteration in the distribution of specific T-cell subsets or whether @entity4329 in cytokine production is a characteristic of @entity1097 individuals. OBJECTIVE: This study examined the production of @entity379 , and @entity1199 in PBMCs from @entity1097 @entity1 at the single cell level with the use of freshly isolated lymphocytes. METHODS: We recently described a flow cytometric assay in which three-color analysis was used to study the production of a cytokine of interest in a T-cell subpopulation defined by two cell surface markers. PBMCs from 23 @entity1097 @entity1 and 14 control subjects were stimulated with @entity4621 and @entity1360 for 5 hours. PBMCs from seven @entity1 and seven control subjects were also cultured with immobilized anti-CD3 antibodies for 24 hours. Cells were fixed, made permeable, and stained for intracellular cytokines in combination with cell surface markers CD3, @entity405 , and CD45RO. Cytokine-producing cells were analyzed by gating on T-cell subsets. RESULTS: @entity379 -producing cells were significantly decreased (p < 0.05) in CD4+ T cells but not in @entity405 + T cells of @entity1097 @entity1 . CD45R0+ and CD45R0-T cells showed a decreased proportion of @entity379 -producing cells (p < 0.05 and p < 0.01, respectively). @entity1199 production was diminished in all T-cell subsets (p < 0.01). The number of @entity3646 -producing cells was not elevated, and such cells were exclusively found in the CD45RO+ T cells. Analysis of culture supernatants of sorted CD45RO+ T cells for @entity3646 and @entity379 production confirmed these results. CONCLUSION: Our findings provide evidence that a reduced @entity379 production in @entity1097 @entity1 is due to an intrinsic defect selectively found in the CD4+ T cells. Because @entity1199 production was markedly decreased but @entity3646 production was unchanged, our data demonstrate a deficiency in the ability of @entity1619 cells to produce @entity1198 -like cytokines on stimulation with @entity4621 , @entity1360 , or anti-CD3 monoclonal antibodies.
  