In this research planning grant for women, experiments are being conducted that will test the effect of immune system proteins, interleukin 1 (IL-1) and tissue necrosis factor alpha (TNF alpha) on steroidogenic secretion and follicular health in two genetic lines of laying chickens selected for either a high (HA) or low (LA) antibody response to sheep erythrocytes. IL-1 isolated from the chicken macrophage HD 11 cell line and human recombinant TNF alpha will be used to ascertain in vitro granulosa and thecal cell androstenedione and progesterone secretion as affected by an immune protein. Further, follicles will be examined for morphological appearance and the presence of surface hemorrhages prior to cell culture as an indicator of atresia. Ethidium bromide agarose gels of DNA isolated from these same follicles will be used to further substantiate follicular health as determined by the presence or absence of 185 base pair fragments, an indicator of cellular apoptosis. Additional experiments will test the in vivo response of laying hens to a strong immune challenge induced by an intraperitoneal injection of sephadex particles. Follicles will be isolated and examined for morphological appearance as described before. Gonadal cells will be grown in cell culture for the assessment of steroid secretion, followed by the isolation of DNA for an assessment of apoptosis. It is anticipated that isolation of IL-1 from the HD 11 cell line will lead to the determination of the amino acid sequence of the protein. Once this information is obtained, future studies will be developed to clone the gene for IL-1, and use this as a means of assessing immune system proteins as regulators of reproduction in avian species. These experiments will be used to assess the role of the immune system as a regulator of reproductive efficiency. In order to complete these experiments, laying chickens will be used as the research model since follicles destined for ovulation can be predicted precisely as well as those follicles most likely to be excluded from future development. Two experiments will be conducted that will: (1) assess the role of specific immune system proteins, interleukin 1 and tissue necrosis factor alpha, on the secretion of gonadal hormones from cells isolated from ovarian tissue, and (2) measure the secretion of gonadal hormones from ovarian tissues after hens are exposed to a laboratory induced immunological challenge. The effect of immune proteins or an immune challenge on follicular health will be determined by measuring the presence or absence of cellular genetic material (DNA) which has been degraded after the exposure to either of the two treatments. It is hoped that results from these experiments will lead to the isolation of the protein, interleukin 1, from chicken immune system cells. It is further anticipated that future experiments will be planned to determine not only the role of the immune system on reproduction, but how this system and its secretory proteins are controlled.
