Ovine corticotropin-releasing factor increases endocrine and immunologic activity of avian leukocytes in vitro.

Treatment of splenic leukocytes from Cornell K strain male chickens (homozygous at the B15 locus of the major histocompatibility complex) with ovine corticotropin-releasing factor (oCRF), before their co-incubation with naive chicken adrenal cells, resulted in an increase in corticosterone production. Supernatants from the oCRF-treated splenic leukocytes caused a time-dependent increase in corticosterone production when incubated with chicken adrenal cells. Adding oCRF directly to chicken adrenal cells did not increase corticosterone production. Pretreatment of peripheral leukocytes with oCRF increased their activity in a concanavalin A mitogen assay. Thus, chicken leukocytes stimulated with corticotropin releasing factor appear to increase the production of an "adrenocorticotropin-like" substance (adrenocorticotropin-like because it increases corticosterone production by adrenal cells), and increased their cell-mediated immune activity.