LUTTON, B.V.; CALLARD, I.P.; Boston University: Immune-endocrine relationships in the little skate, Raja erinacea

The ovary and epigonal organ of the little skate, Raja erinacea, serve as a potential model for immune-endocrine (gonadal) interactions. In this study we are utilizing histological, cytological, and physiological methods to elucidate possible interactions between these tissues. Formalin fixed epigonal-ovary complexes were stained with hematoxylin and eosin and serial sectioned, and tissue imprints were stained with Wrights and Giemsa, to evaluate morphological association and to determine the cell types present. Cellular studies used collagenase dispersed epigonal and ovarian tissues, followed by culture and co-culture of the cells obtained. Epigonal cells were challenged with 10 ug/mL lipopolysaccharide (LPS) and 500 ug/mL Concanavalin A (Con A) in order to investigate cytokine release using a human cytokine Ab array (Panomics, Redwood City, CA). The presence of TNF-alpha and leptin were demonstrated by cross reactivity, and leptin was also detectable by radioimmunoassay (RIA; Linco Research, Inc., St. Charles, MO) at 10 ng/mL secreted from approximately 3 million cells/mL over 24 hours. In initial cultures of ovarian follicle cells, RIA of conditioned media indicated that sex steroid (E₂ and T, but not P₄) production was enhanced by addition of LPS and Con A, but not by co-culture with epigonal cells. Additional experiments involving epigonal cell and follicle cell co-culture, as well as exposure of follicle cells to leptin and TNF-alpha and exposure of epigonal cells to sex steroids (E₂, T, and P₄) are in progress. This research was supported by an NIH Predoctoral Fellowship to B.L. from NIH 2T32HD07387.