Temperature-mediated processes in teleost immunity: binding and mitogenic properties of concanavalin A with channel catfish lymphocytes.

Low (non-permissive) temperatures inhibit the proliferation responses of channel catfish T cells to stimulation with Con A. The study reported here was undertaken to ascertain if failure to bind Con A at non-permissive temperatures could explain the observed suppression at such temperatures. The influence of temperature on the binding of fluorescein-labelled succinyl Con A to channel catfish T and B cells was studied by cytofluorography. The results indicated that Con A bound equally well at both mitogenically permissive (22 degrees, 27 degrees and 32 degrees) and non-permissive (12 degrees and 17 degrees) temperatures. Hence, temperature effects on mitogen-binding to cell surface receptors cannot readily explain the observed suppression of channel catfish T-cell proliferative responses at non-permissive temperatures.