Barrier Tissue-Specific Resident Memory B Cells

Man Lee Oh, Department of Medicine, Tokyo University, Tokyo, Japan, Email: Oh.lee@tjmcu.edu.jp

Received: 01-Nov-2022, Manuscript No. EJMJIH-22-78580; Editor assigned: 03-Nov-2022, Pre QC No. EJMJIH-22-78580 (PQ); Reviewed: 17-Nov-2022, QC No. EJMJIH-22-78580; Revised: 24-Nov-2022, Manuscript No. EJMJIH-22-78580 (R); Published: 01-Dec-2022

Description

The body’s first line of defence is made up of epithelial barriers, which comprise the mucosa of the gastrointestinal, pulmonary, and genitourinary systems. Barrier tissues are constantly exposed to microbial threats, thus it’s essential to have a quick response that can handle many invasive infections. B cells’ activity in peripheral organs has been ignored by researchers since B cells are thought to indirectly influence immune responses by producing antibodies. Recent research, however, suggests that the lungs contain tissue-resident memory B cells (BRMs). This population could withstand diverse strains because their defensive reaction was quicker and stronger than that of their circulating counterparts. BRMs may be a good target for vaccine development given these characteristics, but much remains to be learned about them, including their locations, their origins, particular markers, and the mechanisms underlying their establishment and maintenance. The presence of resident B cells in organs other than the lungs provides evidence that these cells play a direct role in the immune responses of numerous non-lymphoid organs. This paper covers significant unanswered questions and provides a timeline of the discovery of BRMs. We will quickly discuss particular traits of humoral immunity that are significant in the peripheral organs. Future studies on B cells found in non-lymphoid organs will offer fresh perspectives that can be used to solve significant issues with relation to human health.

The immune system in our bodies is largely composed of immunological memory. It enables pathogen-specific memory cells to react quickly and forcefully to a pathogen. The body’s barrier tissues are yet another crucial component of protection. Pathogens are prevented from entering our bodies at the first line of defence by mucosal barrier tissues, which include those in the lungs, colon skin, Female Reproductive Tract (FRT), etc. When pathogens invade the mucosa, secretory IgAs, broadly neutralising antibodies and neutralising antibodies attach to them, trapping them there and preventing them from infecting the host cells. While T cell-mediated responses typically produce collateral harm to the host, this effector mechanism is not only effective but also safe because it results in less inflammation at the site of infection. Mature naive B cells that are unique to the pathogen can enter one of four differentiation fates during infection. The extrafollicular response produces short-lived Antibody-Secreting Cells (ASCs) and Germinal Centre (GC) independent Memory B Cells (MBCs) in the early phases of the immune response. These cells have experienced class-switch recombination but have suffered minimal somatic hypermutation. It was hypothesised that resident MBCs in peripheral tissues are not necessary since circulating antibodies serve as the primary foundation for B-cell immunity. In addition, support from GC reactions should be offered for effective antibody synthesis.

There is direct proof that resident Memory B Cells (BRMs) exist in the lungs, according to a recent study, but there hasn’t been any information about BRMs in other organs. We will quickly go through the development of BRMs and the humoral immunity of non-lymphoid barrier tissues in this overview. We’ll assess the likelihood that BRMs occur in non-lymphoid organs besides the lungs. Finally, markers for MBCs and their tissue residency will be examined in comparison to those of resident memory T cells in order to find BRM-specific markers (TRM).

Notably, circulating B lymphocytes cannot access the tissues that make up the lower FRT. It is insufficient to establish PCs and MBCs in the tissue with attenuated HSV-2 immunisation. High amounts of CD80, PD-L2, and CXCR3 are expressed by these cells. CXCR3-ligand chemokine’s, which are generated by IFN-derived from CD4 TRM retained in memory lymphoid clusters, mediate their movement. It is necessary to know this cell population’s location, origin, particular markers, and transcriptional regulators in order to govern it. It is important to identify the various BRM characteristics and the niches in which they can survive in various environments. The parameters that control the creation and development of BRMs can be identified by tracing the origin of BRMs and the interactions between BRMs and the microenvironment. Despite the fact that there isn’t any direct evidence that BRM exists in barrier tissues other than the lung, B cells and ASCs have unique characteristics and have significant functions in a variety of barrier tissues. To fully understand the traits and residency properties of these cells, more research is necessary. Understanding the molecular mechanisms that control how these cells interact with their milieu may help identify the critical determinants of tissue-specific immune characteristics.

Copyright: © 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution NonCommercial ShareAlike 4.0 (https://creativecommons.org/licenses/by-nc-sa/4.0/). This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.