Decreased interleukin-2 responsiveness in leukocytes from Trypanosoma brucei-infected mice

Immunosuppression with respect to those inducible processes which regulate lymphocyte mitogenesis was examined in experimental trypanosomiasis. Splenic leukocytes from Trypanosoma brucei-infected mice showed a decreased proliferative response to the T-cell mitogen concanavalin A. Activated cells secreted normal levels of the endogenous T-cell proliferative signal interleukin-2 (IL-2) and expressed high-affinity IL-2 receptors. However, the ability of activated cells to proliferate in response to exogenous IL-2 was inhibited. These results indicate an impairment of processes which occur after IL-2-receptor binding during lymphocyte mitogenesis. Furthermore, these data indicate that expression of high-affinity IL-2 receptors does not necessarily correlate with an ability to respond to IL-2.     

New locality record for Heterobilharzia americana

Thirty raccoons (Procyon lotor) from three counties in east-central and southeast Kansas (USA) were examined for schistosomiasis. Eleven (37%) of the raccoons had adult schistosomes identified as Heterobilharzia americana present in the mesenteric vessels, histopathological lesions compatible with schistosomiasis, or both. This represents the first report of H. americana in Kansas and in the central United States.