The Placenta in Toxicology. Part I

Abstract

The immune system represents a key defense mechanism against potential pathogens and adverse non-self materials. During pregnancy, the placenta is the point of contact between the maternal organism and non-self proteins of the fetal allograft and hence undoubtedly fulfils immune functions. In the placenta bacteria, foreign (non-self) proteins and proteins that might be introduced in toxicological studies or by medication are barred from reaching the progeny, and the maternal immune system is primed for acceptance of non-maternal fetal protein. Both immunologic protection of the fetus and acceptance of the fetus by the mother require effective mechanisms to prevent an immunologic fetomaternal conflict and to keep both organisms in balance. This is why the placenta requires toxicological consideration in view of its immune organ function. The following articles deal with placenta immune-, control-, and tolerance mechanisms in view of both fetal and maternal aspects. Furthermore, models for experimental access to placental immune function are addressed and the pathological evaluation is elucidated. ''The Placenta as an Immune Organ and Its Relevance in Toxicological Studies'' was subject of a continuing education course at the 2012 Society of Toxicologic Pathology meeting held in Boston, MA.

Combination Effects of (Tri)Azole Fungicides on Hormone Production and Xenobiotic Metabolism in a Human Placental Cell Line

“…However, the limits of the chosen in vitro approach and potential species differences should be considered. The placenta varies in structure as well as in specific functions across species [ 46 , 47 ]. While it is the main producer of progesterone in humans in the second and third trimester, in rat progesterone is produced in the ovary over the whole gestation period [ 46 , 48 , 49 ].…”

Preclinical safety evaluation of intradermal SARS-CoV-2 inactivated vaccine (Vero cells) administration in macaques

“…Based on the above analysis, we hypothesized that intradermal immunization might provide a new approach or strategy to solve the problem that anti-novel coronavirus antibodies are not durable or that variant strains can escape immune protection [18] , [19] , [20] . Because rhesus monkeys are similar to humans in anatomy and organ function and their biological characteristics are reliable, genetic background is relatively stable, adaptability is strong, and background information is abundant, they are widely used in pharmacology and toxicology studies [21] , [22] . In this study, according to the relevant regulations and guidelines for assessing the toxicity of repeated dosing, the protocol was established, and the preclinical safety was evaluated [23] .…”

Involvement of blood mononuclear cells in the infertility, age-associated diseases and cancer treatment

“…It has been proposed that augmentation of mammalian cancer growth is a misinterpretation by the body for the growth support of the semi-allogeneic fetal graft containing the MHC alloantigens of the male partner[140]. Trophoblast hybridization with the uterine cavity surface epithelium was observed in the human, rabbit, and other species[141-144]. This is essential for the fetal survival[145].…”