Fish lymphocytes respond to human IL-1.

IL-1 is known to cross species barriers in that IL-1 of one mammalian species can interact with cells of other mammalian species. The work described herein demonstrates that IL-1 can cross phylogenetic classes as IL-1 derived from human peripheral blood lymphocytes (PBL) potentiated the proliferative response of catfish lymphocytes to the T cell mitogen Concanavalin A (ConA). Catfish PBL were separated by density gradient centrifugation and used in blastogenic transformation assays. IL-1 had relatively little direct stimulatory effect but with suboptimal amounts of ConA there was a significant augmentation of the proliferative response. The specificity of the response was determined by neutralization experiments in which anti-human IL-1 antibody significantly diminished the reaction of catfish lymphocytes to IL-1.