Phylogeny of neuroimmunoregulation: effects of adrenergic and cholinergic agents on the in vitro antibody response of the rainbow trout, Onchorynchus mykiss.

The ability of the nervous system to influence a variety of immune processes has been well established in mammals. There are, however, few studies on how the peripheral nervous system might affect immunity in the lower vertebrates. This study demonstrates that autonomic neurotransmitters (or their analogs) can significantly influence the in vitro induction of antibody-secreting cells in cultures of splenic leukocytes from the rainbow trout. Beta-adrenergic agonists suppress, while alpha-2 adrenergic and cholinergic agonists enhance the in vitro antibody response to the T-independent antigen TNP-LPS. These effects are receptor mediated as evidenced by the action of specific receptor antagonists. These results, taken with the previous findings that the salmonid spleen contains a rich adrenergic innervation, and that chemical sympathectomy results in an enhanced in vivo antibody response, strongly suggest that autonomic neurotransmitters may affect immune function in teleosts via leukocyte receptors for these factors.