Understanding the Immune System in Fetal Protection and Maternal Infections during Pregnancy

Abstract

The fetal-maternal immune system determines the fate of pregnancy. The trophoblast cells not only give an active response against external stimuli but are also involved in secreting most of the cytokines. These cells have an essential function in fetal acceptance or fetal rejection. Other immune cells also play a pivotal role in carrying out a successful pregnancy. The disruption in this mechanism may lead to harmful effects on pregnancy. The placenta serves as an immune barrier in fetus protection against invading pathogens. Once the infections prevail, they may localize in placental and fetal tissues, and the presence of inflammation due to cytokines may have detrimental effects on pregnancy. Moreover, some pathogens are responsible for congenital fetal anomalies and affect almost all organs of the developing fetus. This review article is designed to address the bacterial and viral infections that threaten pregnancy and their possible outcomes. Moreover, training of the fetal immune system against the exposure of infections and the role of CD49a + NK cells in embryonic development will also be highlighted.

Genital Dysbiosis and Different Systemic Immune Responses Based on the Trimester of Pregnancy in SARS-CoV-2 Infection

“…On the other hand, cord blood did not show a significant variation in the upper mentioned immune factors. This could depend on the fact that the fetus responds to the infection via the secretion of other inflammatory factors and that the maternal immune proteins do not necessarily reach the fetus [4,27].…”

Rescue Blood Contamination in scRNA-Seq Data by Originator, a Computational Deciphering Tool using Genetic and Contextual Information

“…For example, in tumor studies, precisely separating blood and tissue-resident immune cells in tumor tissues is crucial for understanding the tumor microenvironment [1]. In placenta tissues interfacing with the mother and fetus, isolating the maternal and fetal cells is pivotal to reveal cellular and immunological differences between them [2]. Moreover, many tissues contain blood vessels, and the resulting scRNA-seq data often include blood cell types (e.g., T cells) having highly similar expression profiles with the same cell types in the resident tissues.…”

Congenital Zika syndrome

“…Vertical, maternal-fetal transmission of Flaviviruses is unusual. It has been proposed that these viruses follow different pathways that vary according to gestational age and the route of maternal infection (vectorial or non-vectorial) to invade and replicate viral proteins in fetal tissue 43,44 .…”