Ebook Janeway''s immuno biology (9/E): Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Janeway''s immuno biology (9/E): Part 2
Ebook Janeway''s immuno biology (9/E): Part 2
493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2most internal tissues are free of active microbial growth, the skin and the various mucosae lining organs that directly contact the external world will have continuous encounters with environmental microbes. These surfaces are where most pathogens Invade. In this chapter, we will discuss the special Ebook Janeway''s immuno biology (9/E): Part 2ized features of the immune system that serves these mucosal surfaces—the mucosal immune system.The mucosal immune system, in particular, that of theEbook Janeway''s immuno biology (9/E): Part 2
gut, may well have been the first part of the vertebrate adaptive immune system to evolve, possibly linked to the need to deal with the vast populatio493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2in the gut of primitive cartilaginous fishes, and two important central lymphoid organs—the thymus and the avian bursa of Fabrlclus—derive from the embryonic intestine. Fish also have a primitive form of secretory antibody that protects their body surface and may be the forerunner of IgA In mammals. Ebook Janeway''s immuno biology (9/E): Part 2 It has therefore been suggested that the mucosal immune system represents the original vertebrate immune system, and that the spleen and lymph nodesEbook Janeway''s immuno biology (9/E): Part 2
are later specializationsThe nature and structure of the mucosal immune system.The first line of defense against Invasion by potential pathogens and c493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2 so Its barrier function needs to be supplemented by defenses provided by the cells and molecules of the mucosal immune system. The innate defenses of mucosal tissues, such as antimicrobial peptides and cells bearing Invariant pathogen-recognition receptors, are described In Chapters 2 and 3. In thi Ebook Janeway''s immuno biology (9/E): Part 2s chapter we concentrate on the adaptive mucosal immune system, highlighting only those Innate responses that are of particular importance to our discEbook Janeway''s immuno biology (9/E): Part 2
ussion. Many of the anatomical and immunological principles underlying the mucosal immune system apply to all Its constituent tissues; here we will us493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2.12-1 The mucosal immune system protects the internal surfaces of the body.The mucosal immune system comprises the internal body surfaces that are lined by a mucus-secreting epithelium—the gastrointestinal tract, the upper and lower respiratory tract, the urogenital tract, and the middle ear. It als Ebook Janeway''s immuno biology (9/E): Part 2o includes the exocrine glands associated with these organs, such as the conjunctivae and lacrymal glands of the eye, the salivary glands, and the lacEbook Janeway''s immuno biology (9/E): Part 2
tating breast (Fig. 12.1). The mucosal surfaces represent an enormous area toIN THIS CHAPTERThe nature and structure of the mucosal immune system.The 493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2The tissues of the rrxxx-sa' immune system are the lymphoid organs and cells associated with the htestine. respiratory tract, and urogenital tract, as well as the oral cavity. pharynx, middle ear, and the glands associated with these tissues, such as the calvary glands and lachrymal glands. The lact Ebook Janeway''s immuno biology (9/E): Part 2atng breast is also part of the mucosal mmune System.be protected. The human small intestine, for instance, has a surface area of almost 400 m2, whichEbook Janeway''s immuno biology (9/E): Part 2
is 200 times that of the skin.The mucosal immune system forms the largest part of the body’s Immune tissues, containing approximately three-quarters 493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2 entering from the environment. When compared with lymph nodes and spleen {which in this chapter we will call the systemic Immune system), the mucosal immune system has many unique and unusual features (Fig. 12.2).Fig. 12.2 Distinctive features of the mucosal immune system. The mucosal mmuno system Ebook Janeway''s immuno biology (9/E): Part 2is bigger, encounters a wder rang© of antigens, and encounters them much more frequently than the rest of the immune system —what we cal in ths chapteEbook Janeway''s immuno biology (9/E): Part 2
r the systemic rnmune system. Thts >s reflected in dcbnctn-o anatomical features, spociaized mechanisms for the uptake of antigen, and unusual effecto493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2osal Immune systemAnatomita' teatưesIntimate imeracticns between mucosal eprthaia and tjmphoid tissuesDiscrete compartments of diffuse lymphad tissue and mere organized structures such as Peyer's patches, Eclated tjmphoid fdlictes. and tonsisspeciaized antigen-uptake mechanisms, eg. M cels in Peyer’ Ebook Janeway''s immuno biology (9/E): Part 2s patches. atenokfs. arxl tonsilsEffector inechanisTisActivatedi'menxry T cells predominate even in the absence of infectionMultiple activated ’naturaEbook Janeway''s immuno biology (9/E): Part 2
l etfectcr/regulatory T cells presentSecretory IgA antiboriesPresence of drsao-.trre micrcttotaimmurregUafcry environmentActive dmnregjlation of immun493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2ally from mucosal infectionsBecause of their physiological functions in gas exchange (the lungs), food absorption (the gut), sensory activities (eyes, nose, mouth, and throat), and reproduction (uterus and vagina), the mucosal surfaces are thin and permeable barriers to the Interior of the body. The Ebook Janeway''s immuno biology (9/E): Part 2 importance of these tissues to life means that effective defense mechanisms are essential to protect them from invasion. Equally significant is thatEbook Janeway''s immuno biology (9/E): Part 2
their fragility and permeability create obvious vulnerability to infection, and it is not surprising that the vast majority of Infectious agents Invad493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2rm infestations continue to be the major causes of death throughout the world, especially in infants in developing countries. To these must be added the human immunodeficiency vims (HIV), a pathogen whose natural route of entry via a mucosal surface Is often overlooked, as well as other sexually tra Ebook Janeway''s immuno biology (9/E): Part 2nsmitted infections such as syphilis.Ute mucosal surfaces are also portals of entry for a vast array of foreign antigens that are not pathogenic. TillEbook Janeway''s immuno biology (9/E): Part 2
s Is best seen In the gut. which Is exposed to enormous quantities of food proteins—an estimated 30-35 kg per year per person. At the same time, the h493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2organisms, or the microbiota. These bacteria are present at levels of at least 1012 organisms per milliliter in the colon contents, making them the most numerous cells in the body by a factor of 10. Substantial populations of viruses and fungi are also found In the healthy Intestine. In normal circu Ebook Janeway''s immuno biology (9/E): Part 2mstances these organisms do no harm, and many are beneficial to their hosts, having important metabolic functions, as well as being essential for normEbook Janeway''s immuno biology (9/E): Part 2
al Immune function. The other mucosal surfaces are also colonized by substantial populations of resident commensal organisms (Fig. 12.4).Fig. 12.3 Muc493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2 mucosal surfaces or enter the body through these routes. Respratory infections are caused by numerous bactena (such as Streptococcus’.pneumoniae and HaemophiVs influenzae. which cause pneumonia; and Bordete'ia pertussis. the cause of whocpng cough) and vruses (such as infbenza and respratory Syncyt Ebook Janeway''s immuno biology (9/E): Part 2ial virus). Diarrheal diseases are caused by both bacteria (such as the cholera bacterium Cholera vibrio] and vruses (such as rotaviruses). The humanEbook Janeway''s immuno biology (9/E): Part 2
immunodeficiency virus |WV) that causes AIDS enters through the mucosa of the croạenità tract or is secreted into breast mik and passed from mother to493The Mucosal Immune System12Adaptive immune responses are typically initiated in the peripheral lymph nodes that drain the infected tissues. While m Ebook Janeway''s immuno biology (9/E): Part 2self as a systemic dsease, but It orọnaiiy enters via the oral'1 respratory route Hepatitis B IS also a sexually transmitted virus. Finaty, parasitic worms inhabiting the intestine cause chronic debilitating deease and premature death Most of these deaths, especially these frem dOJte respratory and Ebook Janeway''s immuno biology (9/E): Part 2dianheal diseases, occur in chidren under 5 years od in the developing world, and there are Still no effects vaccines against many of these pathogensEbook Janeway''s immuno biology (9/E): Part 2
Numbers shown are the meet recent estimated figues available (The Global Burden of Disease; 2304 Update. World Health Organization, 20081 •Does not inGọi ngay
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