Conservation of IL-6 trans-signaling mechanisms controlling L-selectin adhesion by fever-range thermal stress.

Fever is associated with improved survival during infection in endothermic and ectothermic species although the protective mechanisms are largely undefined. Previous studies indicate that fever-range thermal stress increases the binding activity of the L-selectin homing receptor in human or mouse leukocytes, thereby promoting trafficking to lymphoid tissues across high endothelial venules (HEV). Here, we examined the evolutionary conservation of thermal regulation of L-selectin-like adhesion.

Mammary tumor latency is increased in mice lacking the inducible nitric oxide synthase.

Nitric oxide (NO) and its metabolites are implicated in carcinogenesis and metastasis. Both stimulatory and inhibitory effects of NO have been reported in relation to breast cancer and its role in the development of malignancies and metastasis remains uncertain. We have used the polyomavirus middle T antigen (PyV-mT) targeted to the mouse mammary gland and bred into an inducible NO synthase (iNOS)-deficient C57Bl/6 strain to examine a role for nitric oxide in modulating tumors that develop in the complex environment of the whole animal.