Mucosal Immunity Overview

<p>It focuses on pathogens at mucosal surfaces. (A)</p> Signup and view all the answers

<p>Using specialized transport mechanisms like transcytosis (B)</p> Signup and view all the answers

<p>Capturing and delivering antigens to mucosal dendritic cells. (D)</p> Signup and view all the answers

<p>SIgA (C)</p> Signup and view all the answers

<p>By presenting food antigens to CD4+ TREG cells, leading to downregulation of inflammatory responses. (D)</p> Signup and view all the answers

<p>The lamina propria, where they secrete pIgA. (A)</p> Signup and view all the answers

<p>It transports dimeric IgA (pIgA) and pentameric IgM across mucosal epithelial cells. (A)</p> Signup and view all the answers

<p>To prevent excessive inflammation due to the presence of LPS from commensal Gram-negative bacteria. (A)</p> Signup and view all the answers

<p>A separation of inductive and effector sites to regulate immune responses effectively. (A)</p> Signup and view all the answers

<p>SIgA contains a secretory component (secretory piece) that enhances stability, while pIgA does not. (C)</p> Signup and view all the answers

<p>The corona. (A)</p> Signup and view all the answers

<p>It is a pentamer linked by a J chain, facilitating transcytosis. (D)</p> Signup and view all the answers

<p>Because they are inductive sites where antigens are presented and lymphocytes are activated. (B)</p> Signup and view all the answers

<p>Via transcytosis through M cells. (C)</p> Signup and view all the answers

<p>It plays an important role in the mucosal immunity of the oral cavity. (D)</p> Signup and view all the answers

<p>The transport of pIgA through mucosal epithelial cells to the gut lumen via the pIgR. (A)</p> Signup and view all the answers

<p>Antigen Presenting Cells (APCs) (B)</p> Signup and view all the answers

<p>Antigen uptake and presentation (A)</p> Signup and view all the answers

<p>Lamina propria (D)</p> Signup and view all the answers

<p>D-MALT (B)</p> Signup and view all the answers

<p>The presence of follicles and germinal centers (B)</p> Signup and view all the answers

<p>Secretion of effector molecules (D)</p> Signup and view all the answers

<p>Diffuse and disorganized (D)</p> Signup and view all the answers

<p>Isotype switching (A), Somatic hypermutation (SHM) (C)</p> Signup and view all the answers

<p>Mucosal tissues (C)</p> Signup and view all the answers

<p>pIgA (C)</p> Signup and view all the answers

<p>αβ memory CTLs (C)</p> Signup and view all the answers

<p>Salivary glands (B)</p> Signup and view all the answers

<p>Recognizing lipid antigens (C)</p> Signup and view all the answers

<p>Follicle Associated Epithelium (FAE) (C)</p> Signup and view all the answers

<p>γδ T cells (B)</p> Signup and view all the answers

<p>MIC-A and MIC-B (D)</p> Signup and view all the answers

<p>Kill infected epithelial cells (C)</p> Signup and view all the answers

<p>To form a thick barrier against pathogens (C)</p> Signup and view all the answers

<p>Paneth cells (C)</p> Signup and view all the answers

<p>Every 6-12 hours (C)</p> Signup and view all the answers

<p>To recognize and bind to specific carbohydrates on pathogens (A)</p> Signup and view all the answers

<p>Beta-defensins (C)</p> Signup and view all the answers

<p>It provides a physical barrier to microbial contact (A)</p> Signup and view all the answers

<p>Various cytokines (D)</p> Signup and view all the answers

<p>Defensin production (D)</p> Signup and view all the answers

<p>They permeabilize microbial membranes (A)</p> Signup and view all the answers

<p>It provides a barrier against pathogens (D)</p> Signup and view all the answers

<p>Active transepithelial transport across the epithelial barrier (B)</p> Signup and view all the answers

<p>Beneath the M cell (B)</p> Signup and view all the answers

<p>B cell activation and interactions increase (B)</p> Signup and view all the answers

<p>In the mesenteric lymph node (A)</p> Signup and view all the answers

<p>SIgA (A)</p> Signup and view all the answers

<p>Affinity maturation and somatic hypermutation (D)</p> Signup and view all the answers

<p>They travel to the mesenteric lymph node before proliferation (B)</p> Signup and view all the answers

<p>Cytokines produced by activated T cells (D)</p> Signup and view all the answers

<p>Lamina propria (D)</p> Signup and view all the answers

<p>Mucosal surfaces as SIgA (A)</p> Signup and view all the answers

MALT is a part of the immune system associated with mucosal membranes, providing defense against pathogens.

These include lymphocytes, macrophages, and specialized epithelial cells that play roles in immune defense in mucosal areas.

These include specific antibodies, enzymes, and immune cells that protect mucosal surfaces from pathogens.

Mucosal immunity focuses on localized responses, while humoral immunity involves antibodies throughout the body.

This involves how immune cells and pathogens move within and between mucosal tissues during immune responses.

The immune response that occurs in mucosal tissues, involving specialized lymphocytes and antibodies.

Mucosa-associated lymphoid tissue, responsible for immune responses at mucosal surfaces.

Organized MALT where immune responses are induced, containing active lymphoid follicles.

Diffuse MALT where effector functions, like antibody secretion, occur without structures.

Locations (O-MALT) where antigens are presented and lymphocytes are activated.

Locations (D-MALT) where activated lymphocytes secrete effector molecules.

Gut-associated lymphoid tissue, a type of O-MALT found in the digestive tract.

Nasal-associated lymphoid tissue, a type of O-MALT located in the nasal area.

A thick layer preventing pathogens from reaching gut epithelium, produced by goblet cells.

Mucin molecules in mucus turnover every 6-12 hours, taking bound pathogens with them.

The gut produces several liters of mucus daily as part of immune defense.

A membrane-bound layer of mucin and glycolipids providing a physical barrier against microbes.

α-defensins produced by Paneth cells permeabilize microbial membranes without harming gut bacteria.

β-defensins produced by absorptive epithelial cells, respond to bacteria and IL-1.

Chron’s disease involves a defect in defensin production, its causation is unclear.

Secretion from Paneth cells, known as REG III proteins, involved in gut defense.

These proteins from C-type lectins help in gut immunity and microbial homeostasis.

Cytokines induce the production of mucin molecules to enhance gut defense.

Clusters of lymphoid follicles in the intestine involved in gut immunity.

Polymeric immunoglobulin A, an antibody produced mainly in mucosal areas.

Secretory immunoglobulin A, formed when pIgA is secreted across epithelial layers.

T cells located between mucosal epithelial cells, involved in immune response.

A subset of T cells present in IELs, important for lipid antigen recognition.

Polymeric immunoglobulin receptor that transcytoses pIgA and pIgM.

Specialized epithelial layer covering Peyer’s patches.

Antigen is taken across the epithelial barrier by active transepithelial transport before APC phagocytosis.

Specialized cells that transcytose antigens across the epithelial barrier to the immune cells below.

APCs capture antigens and present them to T cells in the dome area of Peyer's patches.

Upon receiving antigens from APCs, T cells become activated to help the immune response.

The process where activated B cells switch their antibody type, often to IgA, to enhance the immune response.

B cells with mIgA proliferate and differentiate in the germinal center of mesenteric lymph nodes.

B cells that retain memory of antigens and can quickly respond upon re-exposure.

Memory mIgA B cells exit lymph nodes to secrete IgA into the lamina propria for protection.

Plasma cells in the lamina propria secrete pIgA, which associates with pIgR to become SIgA.

The process where B cells increase the strength of their affinity for a specific antigen via somatic hypermutation.

TLR4 expression is reduced to limit inflammation from commensal bacteria.

Includes pIgA, IgG, pIgM, specialized cells, and anatomy.

pIgA is produced by plasma cells and transcytosed to form SIgA.

TREG cells are conditioned by food antigens to downregulate inflammation.

The process of transporting pIgA across the epithelium to the gut lumen.

IgG is important in oral mucosal immunity but less in the GI tract.

Inductive sites in the GI tract where lymphocytes are activated.

Peyer's patches contain a large number of antigen-presenting cells (APCs).

Separation of inductive and effector sites enhances immune responses.

These cells help maintain tolerance to food antigens.

Formed by pIgA after transcytosis, important in mucosal immunity.

The dome area under the FAE contains naive B cells.