Mukozal bağışıklığın anahtarı ‘’M’' hücreleri
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Date
2020-08-12
Authors
Dağdeviren, Tuğba
Saraydın, Serpil Ünver
Journal Title
Journal ISSN
Volume Title
Publisher
Bursa Uludağ Üniversitesi
Abstract
Vücuttaki lenfoid dokunun büyük bir kısmı bağırsaklarda bulunur. Burası aynı zamanda yabancı antijenlerin vücuda giriş çıkış yaptığı yerdir. Gıdasal patojenler, komensal bağırsak florası ve istilacı patojenler sindirim sistemi lümeninden vücuda girebilir. Bu patojenlere karşı oluşturulan mukozal bir tabaka engeli vardır. Bu mukoza tabakası, mukoza hücreleri, mikroflora ve bağışıklık sistemine ait hücreler tarafından çevrilmiştir. Mukozal bariyer, immunolojik ya da patojenik potansiyeli yüksek olan faktörlere karşı en önemli savunma mekanizmasıdır. Mukozal epitel içerisine yerleşmiş bağışıklık sistemi hücreleri olan M hücreleri, mukozal bariyerin en önemli bileşenlerinden biridir. T ve B lenfositler, makrofajlar ve bağırsakta bulunan diğer bağışıklık hücreleri ile sürekli etkileşim içindedirler. Bağırsak ilişkili lenfoid doku (GALT) insan vücudunun en büyük lenfoid dokusudur ve neredeyse bağışıklık sistemi hücrelerinin çoğunu barındırır. GALT yapısını Peyer plakları oluşturur. Lenf foliküllerinden oluşan GALT, antijene spesifik IgA üretip, mukozal yüzeye salgılayarak indüktif ve efektör bir fonksiyonla bağışık yanıt oluşmasını gerçekleştirir. Peyer plaklarında M hücresi tarafından alınan antijen, subepitelyal dom bölgesindeki dendritik ya da makrofaj hücreleri gibi antijen sunan hücrelere verilir. M hücreleri, bağırsak epitel bariyeri boyunca bağırsak boşluğundaki partiküllerin, makro ve mikromoleküllerin, mikroorganizmaların aktarımını gerçekleştirir. M hücrelerinin folikül ilişkili epitel ve kript epitelinde bulunan Lgr5+ kök hücrelerden köken aldığı bilinmektedir. M hücrelerinin bilinen en önemli özelliği, mukoza altında yer alan mukoza ilişkili lenfoid dokuya antijen sunmalarıdır. Böylece hem sistemik hem de mukozal immun yanıt oluşturarak mukozal bağışıklığın ilk basamağını gerçekleştirirler. Bu derlemede M hücrelerinin gelişimi, yapısal özellikleri ve fonksiyonları hakkında bilgiler verilmiştir.
Many of the lymphoid tissue in the body is found in the intestines. This is also where foreign antigens enter and exit the body. In our body, food pathogens, commensal intestinal flora and invasive pathogens can enter through the lumen of the digestive system, and there is a mucosal layer barrier created against these pathogens. This mucous layer is surrounded by mucous cells, microflora and immune cells. Mucosal barrier is the most important defense mechanism against factors with high immunological or pathogenic potential. M cells, which are immune system cells located within the mucosal epithelium, are one of the most important components of the mucosal barrier. T and B lymphocytes constantly interact with macrophages and other immune cells found in the intestinal. Intestinal-associated lymphoid tissue (GALT) is the largest lymphoid tissue in the human body and almost contains most of the immune system cells. Peyer plaques form the Galt structure. GALT, consisting of lymph follicles, produces antigen-specific IGA and secretes it onto the mucosal surface, producing an inductive and effector immune response. Peyer plaques are rich in carrying immune cells. The antigen taken by the M cell in Peyer plaques is delivered to antigen presenting cells such as dendritic or macrophage cells in the subepithelial dome region. M cells transport the particles, macro, micromolecules and microorganisms in the intestinal cavity through the intestinal epithelial barrier. It is known that M cells originate from Lgr5 positive stem cells in follicle-related epithelium and crypt epithelium. The most important feature of M cells is that it presents antigens to mucosal-associated lymphoid tissue located under the mucosa. Thus, they perform the first step of mucosal immunity by creating both a systemic and mucosal immune response. This review also provides information about the development, structural properties and functions of M cells.
Many of the lymphoid tissue in the body is found in the intestines. This is also where foreign antigens enter and exit the body. In our body, food pathogens, commensal intestinal flora and invasive pathogens can enter through the lumen of the digestive system, and there is a mucosal layer barrier created against these pathogens. This mucous layer is surrounded by mucous cells, microflora and immune cells. Mucosal barrier is the most important defense mechanism against factors with high immunological or pathogenic potential. M cells, which are immune system cells located within the mucosal epithelium, are one of the most important components of the mucosal barrier. T and B lymphocytes constantly interact with macrophages and other immune cells found in the intestinal. Intestinal-associated lymphoid tissue (GALT) is the largest lymphoid tissue in the human body and almost contains most of the immune system cells. Peyer plaques form the Galt structure. GALT, consisting of lymph follicles, produces antigen-specific IGA and secretes it onto the mucosal surface, producing an inductive and effector immune response. Peyer plaques are rich in carrying immune cells. The antigen taken by the M cell in Peyer plaques is delivered to antigen presenting cells such as dendritic or macrophage cells in the subepithelial dome region. M cells transport the particles, macro, micromolecules and microorganisms in the intestinal cavity through the intestinal epithelial barrier. It is known that M cells originate from Lgr5 positive stem cells in follicle-related epithelium and crypt epithelium. The most important feature of M cells is that it presents antigens to mucosal-associated lymphoid tissue located under the mucosa. Thus, they perform the first step of mucosal immunity by creating both a systemic and mucosal immune response. This review also provides information about the development, structural properties and functions of M cells.
Description
Keywords
GALT, M hücreleri, Mukozal bağışıklık, M cells, Mucosal Immunity
Citation
Dağdeviren, T. vd. (2020). ''Mukozal bağışıklığın anahtarı ‘’M’' hücreleri''. Uludağ Üniversitesi Tıp Fakültesi Dergisi, 46(2), 247-254.