Dehydroepiandrosterone (5-androstene-3 beta-ol-17-one, DHEA) has been shown to protect mice from lethal viral and bacterial infections. However, recently, androstenediol (5-androstene-3 beta-17 beta-diol, AED) and androstenetriol (5-androstene-3 beta-7 beta-triol, AET), metabolites of DHEA, have each shown to be more potent endocrine regulators of the immune response. In contrast to glucocorticosteroids, in vivo, these steroid hormones up-regulated the cellular immune response of the host to limit virus-mediated pathology. These experiments first examined the in vitro influences of DHEA, and AED, or AET on mitogen-stimulated activation of murine lymphocytes. From physiologic to pharmacologic doses, DHEA suppressed proliferation of mixed splenocyte cultures activated with Con A or LPS by 20 to 70% whereas AED had little influence on the response. In sharp contrast, AET potentiated the response with both mitogens to 50 to 70% above control. Analogous to these observations was the regulation of IL-2 and IL-3 secretion from Con A-activated lymphocytes by each of these hormones which again was depressed analyzed. The suppressive effects of hydrocortisone on Con A-induced lymphocyte proliferation and cytokine production were strongly counteracted by coculture with AET. DHEA did not counteract hydrocortisone activity whereas AED showed moderate antiglucocorticoid function.