The Contribution of the Maternal Immune System to the Establishment of Pregnancy in Cattle

Abstract

Immune cells play an integral role in affecting successful reproductive function. Indeed, disturbed or aberrant immune function has been identified as primary mechanisms behind infertility. In contrast to the extensive body of literature that exists for human and mouse, studies detailing the immunological interaction between the embryo and the maternal endometrium are quite few in cattle. Nevertheless, by reviewing the existing studies and extrapolating from sheep, pig, mouse, and human data, we can draw a reasonably comprehensive picture. Key contributions of immune cell populations include granulocyte involvement in follicle differentiation and gamete transfer, monocyte invasion of the peri-ovulatory follicle and their subsequent role in corpus luteum formation and the pivotal roles of maternal macrophage and dendritic cells in key steps of the establishment of pregnancy, particularly, the maternal immune response to the embryo. These contributions are reviewed in detail below and key findings are discussed.

Targeting specific cells in the brain with nanomedicines for CNS therapies

“…This process generally starts from an initial microglia activation, which further develops into increased inflammation and glial activation when M2 responses occur and fail to exert their neuroprotective roles [26]. M1 microglia participates in the chronic inflammation of many neurodegenerative diseases, including AD, PD, ALS, or MS [25, 31-33]. In these instances, microglia respond to stimuli, such as aggregation of Aβ in AD and α-synuclein in PD, motor neuronal death in ALS, or signals from infiltrating lymphocytes in MS; and further produce more NO, ROS, proinflammatory cytokines (such as TNF-α, IL-1β, IL-6) that eventually cause progressive injury to other neurons/astrocytes without appropriate neuroprotective effects from M2 phenotypes [25-27, 34-37].…”

Changes in expression of Th1 and Th2 cytokines in bovine peripheral blood mononuclear cells during early pregnancy

“…It is reported that conceptus-derived signals are involved in the maternal systemic immune regulation through peripheral blood mononuclear cells (PBMC), platelets and cell-free DNA in sera via the lymph circulation and blood circulation (Yang et al, 2014). Immune cells play an integral role in corpus luteum (CL) formation and the pivotal roles in the establishment of pregnancy and the maternal immune response to the embryo (Fair, 2015).…”

C—C motif chemokine ligand 2 regulates lps‐induced inflammation and ER stress to enhance proliferation of bovine endometrial epithelial cells

“…For the maternal immune system to prevent rejection of embryonic semiallograft, IFNT enhances the immune mechanisms at the maternal‐fetal interface by recruitment of monocytes to the endometrium or by regulating differentiation of the endometrium into macrophages or dendritic cells, with high levels of IFN‐induced genes, such as CCL2, CCL8, IL12B, pentraxin 3 (PTX3), radical S‐adenosyl methionine domain containing 2 (RSAD2), and tumor necrosis factor α (TNFA) in the bovine endometrium (Fair, ; Mansouri‐Attia et al, ). In addition, CCL2 is one of the most potent chemoattractants for immune regulatory cells, including monocytes, macrophages, T cells, and uNK cells in the endometrium, and plays a role in uterine cell proliferation, angiogenesis, and remodeling (Jones, Kelly, & Critchley, ; Salamonsen & Lathbury, ).…”

“…For the maternal immune system to prevent rejection of embryonic semiallograft, IFNT enhances the immune mechanisms at the maternalfetal interface by recruitment of monocytes to the endometrium or by regulating differentiation of the endometrium into macrophages or dendritic cells, with high levels of IFN-induced genes, such as CCL2, CCL8, IL12B, pentraxin 3 (PTX3), radical S-adenosyl methionine domain containing 2 (RSAD2), and tumor necrosis factor α (TNFA) in the bovine endometrium (Fair, 2015;Mansouri-Attia et al, 2012). In addition, CCL2…”