To study the effects of sheep red blood cells (SRBC), viable Escherichia coli inoculation and IL-6 administration on steroidogenesis, activities and expression of hydroxy steroid dehydrogenase enzymes (3βHSD and 17βHSD) were measured in lymphoid organs of control and infected mice after 3 weeks treatment. Serum testosterone and cytokine levels were also estimated. Reduced expression of 3βHSD4 was found in the spleen of treated groups as compared to control, whereas the 3βHSD4 expression was increased in the thymus and lymph gland after stimulation. Reduced serum testosterone level was observed after antigenic stimulation and also altered serum IL-12p70, TNF-α, IFN-γ, MCP-1 or IL-10 level. These studies provide the evidence of expression of 3βHSD4 enzyme in the murine lymphoid organs after particulate antigen stimulation along with a parallel alteration in endogenous cytokine level. © 2009 Elsevier Inc. All rights reserved.