Cytokines, dendritic cells and toll-like receptors in the success and failure of porcine pregnancy
Commercial swine exhibit two spontaneous waves of conceptus loss during gestation. Arresting conceptus attachment sites are associated with decreased angiogenesis and elevated pro-inflammatory cytokine production by lymphocytes. No studies have addressed type 1 and 2 cytokine ratios in pregnant pigs or the presence of DC-SIGN+ DCs, their activation status and angiogenic potential. I hypothesized that type 1 and 2 cytokine ratios are altered at the porcine maternal-fetal interface by pregnancy failure. Further, I postulated that DCs contribute to angiogenesis in healthy pregnancy and conceptus loss is associated with engagement of TLRs. Cytokine ratios and TLR expression were quantified at the maternal-fetal interface at early and mid gestation. DC-SIGN+ DC-like cells were found and their expression of TLRs and angiogenesis-related molecules was addressed. These studies implicate endometrial DC-like cells in the regulation of angiogenesis in pig pregnancy and provide a model for roles of DCs in human pregnancy loss.