Temperature-Mediated Processes in Teleost Immunity: Homeoviscous Adaptation in Teleost Lymphocytes 1

Abstract

Abstract

In vitro studies with pinfish (Lagodon rhomboides) lymphocytes demonstrated that the temperature to which a fish is acclimated in vivo affects the temperature dependence of lymphocyte responses to mitogenic stimulation with conconavalin A (ConA) in vitro, i.e., at an in vitro temperature of 20°, the lymphocytes of 17° acclimated fish responded to ConA better than the lymphocytes of 27° acclimated fish. Fluidity measurements of plasma membranes from lymphocytes isolated from both cold- and warm-acclimated pinfish were made using fluorescence polarization spectrophotometry and the fluorescent membrane probe, 1,6-diphenyl-1,3,5-hexatriene. While the membranes of cold-acclimated pinfish were more fluid than those of warm-acclimated fish when both were measured at the same temperature, the fluidities were equal when measured at the respective acclimation temperatures. These results support the hypothesis that the process of homeoviscous adaptation of lymphocyte plasma membranes may be an important aspect of teleost immunity.