BULLETIN OF THE EUROPEAN ASSOCIATION OF FISH PATHOLOGISTS
Abstract
A rapid tetrazolium (MTT) based colorimetric assay was used to evaluate the in vitro cellular immune reactivity of sea bass (Dicentrarchus labrax) lymphocytes obtained from peripheral blood, head kidney and spleen, and separated on Hystopaque gradients. Dose response assays were performed using lectins (phytohemagglutinin, concanavalin-A) and bacterial lipopolysaccharide as stimulants. In the leukocyte microtitration assays the best results were observed in head kidney cell cultures maintained in the presence of PHA-P in 12.ìg/ml end concentration, but LPS also caused a definite proliferation, while Con-A proved to lack effect. Peripheral blood .5lymphocytes were stimulated by all three mitogens Con-A, LPS and PHA-P, the highest values were given also by PHA-P in cultures containing the drug in 6.25 ìg/ml concentration. Spleen lymphocytes reacted least to the mitogens, only mild, statistically non significant responses were observed in the presence of the superantigens.
