Fig. 5.

Requirement of exogenous IL-12 for effective IFN-γ production from CD4⁺ T cells cultured with L cells and stimulated with Streptococcus pyrogenic exotoxin A (SPE-A). HLA-DR⁻ CD4⁺ T cells were purified by sorting and cultured with mitomicin C-treated L cells and SPE-A, and culture supernatants at indicated periods were subjected to ELISA.