Induction of intestinal lymphoid tissue formation by intrinsic and extrinsic signals

Abstract

Since the discovery of inducer cells as a separate lineage for organogenesis of Peyer's patches in the small intestine of fetal mice, a lot of progress has been made in understanding the molecular pathways involved in the generation of lymphoid tissue and the maintenance of the lymphoid architecture. The findings that inducer cells also exist in adult mice and in humans, have a lineage relationship to natural killer cells, and can be stimulated during infections highlight their possible role in establishing innate and adaptive immune responses. Novel concepts in the development of intestinal lymphoid tissues have been made in the past few years suggesting that lymphoid organs are more plastic as previously thought and depend on antigenic stimulation. In addition, the generation of novel lymphoid organs in the gut under inflammatory conditions indicates a function in chronic diseases. The present review summarizes current knowledge on the basic framework of signals required for developing lymphoid tissue under normal and inflammatory conditions.

AHR drives the development of gut ILC22 cells and postnatal lymphoid tissues via pathways dependent on and independent of Notch

“…Thus, LTi-like ILC seem to have a predominant role in inducing CP and ILF. Furthermore, the requirement of LTi-like ILC for CP and ILF but not PP emphasizes the heterogeneity of inducer cells and signaling pathways involved in the organogenesis of distinct gut-associated lymphoid tissues 41, 49 .…”

The role of gut microbiota in immune homeostasis and autoimmunity

“…[1][2][3] This gut microbial community (microbiota) has co-evolved with its host over millennia and provides benefits to its host in many ways, including, but not limited to, digestion, production of nutrients, detoxification, protection against pathogens and regulation of immune system. [1][2][3][4][5] The immune system plays a vital role in keeping the body healthy by providing a fine balance between the elimination of invading pathogens and the maintenance of tolerance to healthy self-tissue. However, in the case of patients with autoimmune disorders, the mechanism to maintain selftolerance fails and the result is that the immune system mistakenly attacks and destroys healthy self-tissue.…”

Influence of Plasma Cell Niche Factors on the Recruitment and Maintenance of IRF4 hi Plasma Cells and Plasmablasts in Vaccinated, Simian Immunodeficiency Virus-Infected Rhesus Macaques with Low and High Viremia

“…In contrast, unvaccinated animals had higher levels of inflammation and tissue viral loads, which could have influenced PB/PC frequencies by promoting trafficking to the area and/or by inducing the formation of local isolated lymphoid follicles (47).…”