Influence of pre-ovulatory insemination and early pregnancy on the infiltration by cells of the immune system in the sow endometrium

Spermadhesin PSP-I/PSP-II heterodimer induces migration of polymorphonuclear neutrophils into the uterine cavity of the sow

“…They mostly agree that the PMN-peak is reached somewhere between 3 and 6 h after semen deposition. Such interval agrees with the findings by Assreuy et al (2002), using porcine PSP-I/PSP-II in a rodent model, where the PMN invasion to the site of exposure peaked at 4 h. Inflammation does not stop there, since it has many other components, and PMN presence can still be registered 24 h later (Kaeoket et al, 2003). Moreover, there is major individual variation among females in coping with the inflammatory response, and it is well established that some pig females develop long-lasting post-mating inflammation that evolves into endometritis (De Winter et al, 1992).…”

“…These cells are common in the porcine uterus (Kaeoket et al, 2003) and invading PMNs have been seen to interact with intra-epithelial macrophages (Rodriguez-Martinez et al, 1990). Mast cells are also able to produce IL-4 and IL-10, inhibitory of inflammation (Ribeiro et al, 1991).…”

“…The other spermatozoa, the major proportion, are removed from the uterine cavity by retrograde flow (20-25% of the spermatozoa leaving within 30 min, Steverink et al, 1998), while the rest are trapped (neutrophil extracellular traps, [NETs], Alghamdi et al, 2009) and phagocytosed by invading polymorphonuclear granulocytes (PMNs), which apparently start entering the lumen ~10 min after artificial insemination (AI), peak entry by 30 min and continue to enter for the following 2-3 h (Lovell and Getty, 1968; Viring and Einarsson, 1981; Rodriguez-Martinez et al, 1990), largely exceeding the number of inseminated spermatozoa (Matthijs et al, 2003). This uterine PMN influx is accompanied by accumulation of macrophages, granulocytes and lymphocytes in the endometrial stroma and, to a lesser extent, in the base of the lining epithelium (Rodriguez-Martinez et al, 1990; Bischof et al, 1994;Kaeoket et al, 2003;Robertson, 2007), a picture not seen in the oviduct, except for the mesothelial-covered infundibulum (Jiwakanon et al, 2006) or the presence of lymphocyte-like cells in the base of the SR and the adjoining isthmus segment (RodriguezMartinez et al, 1990).What causes this transient PMN influx and the apparent changes in immune cell phenotypes over time is yet unclear, but components of the SP seem to play a role. The SP initiates the transitory inflammatory response (O'Leary et al, 2004) followed by a secondary recruitment of antigen-presenting cells (macrophages and dendritic cells), prerequisite for the generation of paternal antigen-specific maternal T cells (Schuberth et al, 2008) that can recognize and respond to paternal major histocompatibility (MHC) antigens.…”

Infiltration of Local Immune Cells in the Sow Reproductive Tracts after Intra-Uterine and Deep Intra-Uterine Insemination with a Reduced Number of Spermatozoa is Less than Conventional Artificial Insemination

“…After insemination, excessive sperm are eliminated by the local immune cells of the sow endometrium [2,8]. These immune cells are produced from either lymphoid (e.g., lymphocyte, plasma cell) or myeloid lineage (e.g., neutrophil, macrophage and eosinophil) in the bone marrow [2].…”

“…Lymphocyte function is mainly for specific immune response, while neutrophil function is for the non-specific immune response and phagocytosis [2]. The infiltration of the leukocyte subpopulation in the sow uterus and oviduct in non-mated gilts [11], normal cycle sows [12] and at different time periods after CAI has been reported [2,6,8]. However, infiltration of the leukocyte subpopulation after IUI and DIUI has never been investigated.…”