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Fatigue
Published in Carolyn Torkelson, Catherine Marienau, Beyond Menopause, 2023
Carolyn Torkelson, Catherine Marienau
Gut-associated lymphoid tissue is the largest mass of lymphoid tissue in the body and is situated throughout the GI tract. It consists of many types of immune cells, including lymphocytes, as well as collections of tissues involved in immune function, such as the tonsils. The role of GALT is to manage your immune response from the massive antigen exposure experienced by the gut and help prevent you from getting an infection. It’s your gut that fights off environmental and food toxins that enter your body. GALT depends on a healthy intestinal microbiome to function at its best.
Mucosal B cells and their function
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Jo Spencer, Edward N. Janoff, Per Brandtzaeg
Exogenous stimuli from the gut lumen are transported into GALT via M cells in the FAE, probably aided by dendritic cells, which have been shown in mice to be capable of sending processes through the epithelium into the lumen to sample lumenal antigens. Antigens that reach the intraepithelial and subepithelial compartments of GALT encounter a mixed lymphocyte population of B and T cells in a microenvironment that also is rich in macrophages and dendritic cells. Macrophages and dendritic cells in the dome region form a critical first line of defense beneath the epithelium that can influence downstream immunologic events and B-cell function in adjacent organized lymphoid follicles and beyond.
Lymphatic Tissues And Cellular Immune Reactions
Published in Miroslav Holub, Immunology of Nude Mice, 2020
Interestingly, the GALT seems to be more affected by the low supply of recirculating lymphocytes and there is no conspicuous IDC accumulation and hypertrophy of the T areas such as that which occurs in the lymph nodes.1,4,23,32 Also, the repopulation after thymus cell transfer from adult “syngeneic” donors was minimal and slow, compared to other tissues.33 The altered homing conditions described in nude mice34 may be especially pronounced here, and the IDC precursors, e.g., veiled cells, may proceed from the gut wall into the mesenteric lymph nodes19 without contributing to the hypertrophy of the area just as in the nodes. The defective GALT obviously has some bearing for the postnatal activation of mononuclear phagocytes (Chapter 7) and for the induction of oral tolerance.35
The injuries of spleen and intestinal immune system induced by 2-Gy 60Co γ-ray whole-body irradiation
Published in International Journal of Radiation Biology, 2023
An Wang, Zhongyu Shi, Lei Wang, Yan Wang, Xiaoying Chen, Changhao He, Xiaomeng Zhang, Wenhui Xu, Qian Fu, Tieshan Wang, Shujing Zhang, Yushan Gao, Sumin Hu
Intestine is not only an important organ for digestion and absorption, but also an important place for immune response. The intestinal immune system is mainly composed of GALT, associated cells, and associated molecules, which plays an essential role in maintaining intestinal immune homeostasis, mediating immune responses, and regulating inflammation (Kuai et al. 2021). GALT are located throughout the intestine and include PP, MLN, isolated lymphoid follicles (ILF) (Liu, Yin, et al. 2020), IEL as well as lamina propria lymphocytes (LPL) (Kaneko et al. 2005). MLN and PP are inductive sites, while lamina propria and IEL are effector sites (Chen et al. 1998). So, the T cells in IEL are derived or at least partially derived from MLN and PP. In this study, a significant decrease of IEL count was observed at the first day after irradiation. We contend it not only due to the direct damage by γ-ray, but also relate to the reduced lymphocyte source from MLN and PP. In addition, at day 21 after exposure, the IEL and PP lymphocyte counts returned to the normal level, however the MLN lymphocyte counts did not recover completely, suggesting the recovery of MLN was later than that of PP and IEL.
Recent strategies driving oral biologic administration
Published in Expert Review of Vaccines, 2021
Badriyah Shadid Alotaibi, Manal Buabeid, Nihal Abdalla Ibrahim, Zelal Jaber Kharaba, Munazza Ijaz, Ghulam Murtaza
Dendritic cells also generate retinoic acid in the GALT. The interaction of retinoic acid with activated T cells leads to the expression of homing receptors, which mediate IgA+ B cell migration to the mucosal effector area in the lamina propria. IgA+ B cells undergo differentiation and maturation and produce IgA-producing plasma cells, which generate antigen-specific IgA. The basal surface of the enterocyte epithelium exhibits polymeric Ig receptors, which experience binding with IgA. As a result, IgA binding from the lamina propria with basolateral polymeric Ig receptor, resulting in its internalization and transfer through enterocytes. After it, IgA internalization and translocation to the luminal surface occur, where its secretion occurs as a primary molecule capable of eliciting an immune response. The neutralization of the pathogen under the effect of this secretory IgA endows the effector site features to the GI epithelial surface [23]. The salivary gland could also be a source of secretory IgA in the oral cavity [54,55].
Role of dendritic cells in peanut allergy
Published in Expert Review of Clinical Immunology, 2018
Raquel Aguilera-Insunza, Luis F. Venegas, Mirentxu Iruretagoyena, Leticia Rojas, Arturo Borzutzky
The main route of exposure to food components is through the mucosal surface of the gastrointestinal tract. This mucosa is lined by a monolayer of columnar intestinal epithelial cells joined by tight junctions, which prevent paracellular traffic, thus forming a barrier between the intestinal lumen and connective tissue [25]. The intestinal immune system is the largest and most complex part of the immune system, reaching approximately 100 m2 [25]. GALT is composed of organized lymphoid structures and a densely packed population of resident immune cells found in the epithelium and underlying lamina propria (LP). Organized structures of GALT include Peyer´s patches (PPs) and isolated lymphoid follicles that are located within the mucosal tissue, as well as mesenteric lymph nodes (MLNs) [23].