Peyer’s Patch Epithelium
Shayne C. Gad in Toxicology of the Gastrointestinal Tract, 2018
The mucosa-associated lymphoid tissue (MALT) is used to describe all the mucosal lymphoid tissues in the body. One component of the MALT is the mucosal intestinal immune system that provides immunological surveillance and includes the GALT or gut-associated lymphoid tissue. Resistance to infectious and neoplastic disease is the raison d’être of the immunological armamentarium (Burleson, 2000). The total immune system of the body consists of a vast network of lymphoid and nonlymphoid cells, communicating via messenger molecules to create a functional immune system to protect against disease. This network, while interconnected via mediator molecules, contains compartmentalized units especially equipped to defend against insults to the integrity of the immune system (Burleson, 2000). The intestinal immune system, like the pulmonary immune system, is an example of such a specialized and compartmentalized system that, while capable of performing all immunological functions locally, is also capable of interacting with the systemic immune system, as reviewed by Burleson (1987, 1995, 1996, 2000) and Lebrec and Burleson (1994).
Thyroid
Pat Price, Karol Sikora in Treatment of Cancer, 2020
Lymphoma of the thyroid is rare, representing 2% of thyroid malignancies and 2% of extra-nodal lymphomas. Chronic autoimmune stimulation, as in Hashimoto’s thyroiditis, is a predisposing factor. There is a strong female predominance, and the median age at diagnosis is in the seventh decade, similar to that of anaplastic cancer, from which it must be distinguished (Figure 4.1e). An analysis of the U.S. National Cancer Database published in 2019 identified 3466 patients between 2004 and 2015. The median all-cause survival was 11.6 years (CI: 11.1 to 12.1 years). The majority were diffuse large B cell lymphoma (DLBCL, 59.5%), with marginal zone lymphoma (18.3%) and follicular and Burkitt lymphoma (8% and 1.9%, respectively) making up the rest.38 Mucosa-associated lymphoid tissue (MALT) is a form of marginal zone lymphoma and is characterized by a low grade of malignancy, slow growth rate, and a tendency for late relapse or second lymphomas in other MALT sites.37
Immunomodulation at Mucosal Surfaces: Prospects for the Development of Antiinfectious and Antiinflammatory Vaccines
Thomas F. Kresina in Immune Modulating Agents, 2020
Apart from the need for maintaining self-tolerance, the MALT has three main functions: to protect against colonization and invasion by the large number of potentially dangerous microbes encountered each day, to prevent uptake of undegraded antigens including foreign proteins derived from ingested food and commensal microorganisms, and, most importantly, to prevent the development of potentially harmful immune responses to these antigens. At variance with the systemic immune apparatus, which is a sterile compartment and can respond vigourously to most invaders, the mucosal immune system guards organs that are replete with foreign matter including microorganisms. It follows that on encounter with a given antigen, the mucosal immune system must select appropriate effector mechanisms and regulate the intensity of its response so as to prevent bystander tissue damage and exhaustion.
High-Altitude-Induced alterations in Gut-Immune Axis: A review
Published in International Reviews of Immunology, 2018
Kunjan Khanna, K P Mishra, Lilly Ganju, Bhuvnesh Kumar, Shashi Bala Singh
An important branch of adaptive immune response that is mostly vulnerable to invading pathogens and infections is mucosal immune system. It is mainly referred as MALT (Mucosa Associated Lymphoid Tissue). MALT has lymphoid cells which covers the mucosal surface to protect the body from harmful pathogens.37 MALT is further classified into other lymphoid tissues on the basis of its location of lining in the organ, for example, MALT lining Bronchus is known as BALT (bronchus-associated lymphoid tissue),38 lymphoid cells lining gut is GALT (gut-associated lymphoid tissue)37 and so on. Secondary lymphoid tissue present in gastrointestinal tract, that is, GALT plays an important role as most of the foreign particles are exposed in the form of food. GALT consists of isolated lymphoid follicles, which are called Peyer's patches (PP) which are considered as immune sensors of the intestine, and it starts the defence against pathogens.39 M-cells are specialized cells in the gastrointestinal tract, which are antigen entry site in the mucosal epithelium of PP.40 M cells acts as gateways to mucosal system as they transport antigen from lumen to the mucosal lymphoid tissues.41 As M cells have the capacity to deliver antigens directly to the mucosal immune initiation sites, they have been recently studied to develop and improve strategies for mucosal vaccines.42–45
Mucosa-associated lymphoid tissue lymphoma of parotid gland with involvement of subglottis and trachea
Published in Acta Oto-Laryngologica Case Reports, 2018
Natsumi Uehara, Naoki Otsuki, Hirotaka Shinomiya, Keiichiro Uehara, Ken-ichi Nibu
Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B-cell lymphoma, first described by Isaacson and Wright in 1983 [1]. This tumor involves a wide variety of extranodal sites, gastrointestinal tract, thyroid and salivary gland, in the setting of chronic local inflammatory or autoimmune disorders, such as Sjögren syndrome (SS) [2]. It is well known that MALT lymphoma often occurs in the parotid gland of the patients with SS [3]. However, MALT lymphoma involving the larynx and trachea is extremely rare regardless of primary or secondary dissemination. Here, we report a case of parotid MALT lymphoma with SS presented as stridor due to subglottic and tracheal involvement and discuss the clinical feature and the management of MALT lymphoma involving the respiratory tract.
Natural and vaccine-induced B cell-derived systemic and mucosal humoral immunity to human papillomavirus
Published in Expert Review of Anti-infective Therapy, 2020
Ralph-Sydney Mboumba Bouassa, Hélène Péré, Mohammad-Ali Jenabian, David Veyer, Jean-François Meye, Antoine Touzé, Laurent Bélec
More globally, mucosal epithelia of the human body were protected by the MALT [28]. The MALT includes all of the immune cells and tissues involved in the defenses of all mucosa of the body, including the upper and lower gastrointestinal and respiratory tracts as well as the lower male and female genital tract [28]. Thus, whatever the mucosa through which the pathogenic organism penetrates inside the body, the immune response put in place is almost the same for all the body’s mucosa [28,29]. However, each mucosal tissue has his own regionalized and specialized lymphoid nodes which coordinate the local immune response [29]. The immune response elicited in the mucosal sites could be divided into two principal pathways according to the nature of the antigen and the main immune cells involved. Briefly, the first phase is the afferent or inductive stage which starts with the detection, the uptake and the preparation of antigen by sentinel local APCs. The digested antigens are then presented by APCs to the lymphocytes population into the regional lymph node. Then, the efferent phase can be carried out according to the signaling pathways Th1 and Th2.
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