Figure 4.

Semiquantitative RT-PCR for detection of IFN-γ, IL-2, or IL-4 mRNA. RNA obtained from unstimulated purified splenic CD4⁺ and CD8⁺ T cells (ex vivo) or after 18 h of stimulation with PMA + ionomycin was reverse transcribed and amplified with oligonucleotide primers specific for IL-2, IL-4, and IFN-γ. Reactions were standarized by performing PCR with oligonucleotides corresponding to cyclophilin and CD3-ε, whose mRNAs should be equivalent in purified T cell populations. +, indicates homozygosity for the wild-type ζ/η or Fcγ alleles; − indicates homozygosity for the mutant ζ/η or Fcγ alleles, as indicated.