Interferon‐γ Production in Antigen Specific T Cell Response: Quantitation of Specific mRNA and Secreted Protein

Interferon gamma (IFN‐γ) production as a measure of cellular sensitization was studied by detection of the cytokine in culture supernatant by enzyme immunoassay (EIA) and by measuring cellular mRNA using the reverse transcriptase polymerase chain reaction (RT‐PCR) method. These assays were compared to the standard lymphocyte proliferation assay as a marker of T cell responsiveness to foreign antigens. When blood donors seropositive for herpes simplex virus (HSV) were compared to seronegative donors, all measurements of cellular sensitization separated the groups without overlap. There were significant correlations between the IFN‐γ mRNA titre and the secreted IFN‐γ (r = 0.57, P = 0.03), and the proliferative response and the secreted IFN‐γ (r = 0.78, P = 0.001), as well as between the IFN‐γ mRNA titre and the proliferative response (r = 0.78, P