Effects of combined treatment with PD‑L1 Ig and CD40L mAb on immune tolerance in the CBA/J x DBA/2 mouse model

Abstract

The embryo is a natural allograft and is the only exception to immune rejection, which reflects maternal immune tolerance towards the embryo. However, pregnancy loss is primarily caused by maternal immune rejection of the embryo. The aim of the present study was to explore the effects of combined treatment of programmed death-ligand 1 (Pd-l1) immunoglobulin (ig) and cd40-ligand (cd40l) monoclonal antibody (mab) on immune tolerance in an abortion-prone mating model. Mice were divided into the normal, spontaneous abortion, Pd-l1 ig, cd40l mab and the Pd-l1 ig + cd40l mab groups. on day 14 of gestation, the embryo resorption abortion rates of all the groups was observed. The maternal hypo-responsiveness to paternal antigens was determined using a mixed lymphocyte response and the splenic cd4 + cd25 + T-cell population, major histocompatibility complex (MHc)-ii + , cd80 + and cd86 + cell populations in pregnant female cBa/J mice were analyzed using flow cytometry. The expression levels of intracellular cytokines in the splenic tissues of pregnant cBa/J female mice were analyzed using western blotting. The Pd-l1 ig + cd40l group displayed the lowest resorption rate compared with the other groups. A significant decrease in the proliferative response of maternal splenic immunocompetent cells against paternal antigens, and a significant increase in the proliferative response of maternal splenic cd4 + cd25 + T cells was observed in the Pd-l1 ig + cd40l group compared with the spontaneous abortion group. The number of MHc-ii + , cd80 + and cd86 + bone marrow-derived dendritic cells (dcs) generated by female mice, and the levels of tumor necrosis factor-α and interferon-γ in the spleens of female mice were significantly decreased in the PD-L1 Ig + CD40L mAb group compared with the spontaneous abortion group. By contrast, interleukin-4 levels were significantly increased in the PD-L1 ig + cd40l mab group compared with the spontaneous abortion group. The results suggested that the administration of Pd-l1 ig + cd40l mab on day 4 of gestation, the period of peri-implantation, may induce paternal antigen-specific immunotolerance, leading to the embryo resorption rate of the abortion-prone model being similar to that of the normal pregnancy model. The results indicate that the combined treatment of Pd-l1 ig and anti-cd40l mabs may serve as a potential therapeutic for pregnancy loss.

Ferroptosis: a double-edged sword mediating immune tolerance of cancer

“…By engaging the P2X7 receptor, ATP subsequently induces the release of pro-inflammatory cytokines by monocytes, macrophages, and microglia, resulting in the death of retinal endothelial cells [ 129 , 130 ]. Additionally, CD40 participates in the pathological process of autoimmune, and anti-CD40 monoclonal antibodies can lead to immune tolerance [ 131 – 134 ].…”

Regulatory T cell adoptive transfer alters uterine immune populations, increasing a novel MHC-IIlow macrophage associated with healthy pregnancy

“…The CBA mouse strain has a reproductive phenotype that is currently characterized as fetal "resorption," describing a fetal loss pathology with a dark necrotic fetal tissue mass at an implantation site (44,45). Many studies have demonstrated that immune interventions, such as maternal injections of cytokines, adjuvants, or blocking antibodies alter the rates of fetal loss in CBA mice (46)(47)(48)(49)(50)(51). Prior studies have also performed adoptive transfers of Tregs from a variety of sources to decrease rates of CBA fetal loss (21, 44,[52][53][54][55].…”