Production of T cells by skin matrix explant cultures. CTCL and normal skin explants were cultured under various conditions, and T-cell production was assayed. The number of T cells produced from CTCL skin explants was significantly higher than from normal skin explants. Normal skin explants treated with Th2 cytokines IL-4 and/or IL-13 did not produce more T cells. Normal skin explants treated with recombinant human IL-7 produced more T cells than untreated cultures. The addition of anti-human IL-7 neutralizing antibody to CTCL skin explants decreased the numbers of T cells produced.