Decreased in vivo and in vitro colony stimulating activity responses to bacterial lipopolysaccharide in C3H/HeJ mice.

Mice of the C3H/HeJ strain exhibit low inflammatory and immunological responses to certain bacterial lipopolysaccharide (LPS) preparations. Lymphocytes from C3H/HeJ mice also show defective LPS-induced mitogenesis. We tested the colony stimulating activity (CSA) response of C3H/HeJ mice. As controls we used mice of the congenic C3HeB/FeJ strain, which are good responders to LPS. Serum was obtained three hours after intravenous administration of LPS. Serum CSA was determined in agar cultures of bone marrow cells from AKR mice. The serum CSA response of C3H/HeJ to 10 microgram LPS was approximately 8-fold lower than that of control C3HeB/FeJ mice. In contrast, both strains showed similar serum CSA-induced by Poly I:poly C. Peritoneal macrophage cultures were also incubated with 0.1-10.0 microgram LPS and culture media assayed for CSA. The response of C3H/HeJ macrophages was about 6-fold lower than that of macrophages obtained from the control mice. The results show that the lower responsiveness of C3H/HeJ mice to LPS also extends to the production of CSA. The in vitro findings indicate that the postulated defect in the LPS receptor of B lymphocytes may also be present on macrophages.