Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Lymphokine production was analyzed in murine spleen lymphocytes stimulated with different T cell mitogens. Using <jats:italic>in situ</jats:italic> hybridization, frequencies of cells and the kinetics of production of interleukin (IL) 2, 4 and 5 were analyzed. The different mitogens varied in their ability to induce the three interleukins. IL 2 was most successfully induced with a high dose of the calcium ionophore A23187 combined with phorbol 12‐myristate 13‐acetate (PMA). Significant frequencies of cells containing IL 4 or IL 5 mRNA were found among cells stimulated with an anti‐CD3 antibody together with PMA, or pokeweed mitogen. The combination of anti‐CD3 and PMA induced relatively high frequencies of all three cytokines. The production was sequential with the highest levels of IL 2 mRNA present during the first 24 h, IL 4 mRNA reaching a peak on day 2 and finally IL 5 peaking on day 3. When cells that had been stimulated with mitogens <jats:italic>in vitro</jats:italic> were restimulated, the lymphokines were produced more rapidly. The order of production was maintained with IL 2 mRNA reaching a maximum already at 3 h of culture, IL 4 mRNA at 8 h and IL 5 mRNA at 24 h.</jats:p>