Erythropoietic activity and interferon production in LCM virus-infected nude mice.

The distinct haemopoietic lesions induced in ordinary mice during acut LCM virus infection are not mediated either by immunopathological mechanisms or by a direct cytopathogenetic effect of the virus. Medication has recently been artibuted to the high interferon activity found in mice with acute LCM virus infection. In this work, erythropoietic activity and interferon production have been studied in LCM virus-infected nude mice. Compared with ordinary mice, nude mice displayed a more moderate suppression of erythropoiesis and a very poor interferon response. Erythropoietic activity of thymus-transplanted nude mice was not significantly suppressed during the infection, and interferon responsiveness was not restored either by thymus-transplantation or by transfer of large numbers of spleen lymphocytes. The observations support the hypothesis that interferon plays a decisive role in the induction of haemopoietic diorders of mice with acute LCM virus infection. The puzzling question as to why nude mice and reconstituted nude mice are incapable of mounting a normal interferon response is discussed briefly.