Chapter 10: Preventing Infection At Mucosal Surfaces Flashcards
Three parts to body’s defense agains infection
- Innate and adaptive immunity
- preventing infection (ex. Mucosal tissues)
- immunological memory and secondary immune response
- bridging innate and adaptive immunity (help each other)
Mucosae
- is everywhere in our body
- anywhere where air comes into contact with tissue, mucous must be there
Gastrointestinal tract
- activities such as immunological, food adsorption, takes place
Ring of Lymphoid Organs
- guards the entrance to the gastrointestinal and respiratory tracts (Waldeyer’s Ring)
Lymphoid Follicles
- present in the gut wall along with lymphoid tissue
Microfold cells (M cells)
- and dendritic cells facilitate transport of microbes from the gut lumen to gut-associated lymphoid tissue
- adaptive immune responses in the gut are initiated and maintained by M cells that sample the gut’s content
Mucins
- are gigantic glycoproteins that endow the mucus with properties to protect epithelial surfaces
Gut-Associated Lymphoid Tissues
- has fingerlike processes (villi) covered by a layer of thin epithelial cells that are specialized for the uptake and further breakdown of already partly degraded food coming from the stomach
How are adaptive immune responses in the gut initiated and maintained?
- by M cells that sample the gut’s content
- they deliver this material to pockets on the basolateral side of the M-cell membrane
- here, dendritic cells and B cells take up antigen and stimulate the proliferation and differentiation of antigen specific T cells
Effector Lymphocytes populate healthy ___________ tissue in the absence of infection
- mucosal
Most immune-system cells in mucosal tissues are activated ______________ ________.
- effector cells
Outside the lymphoid tissues, the gut ____________ contains ________ T cells
- epithelium
- CD8
The lamina propria is well populated with _______ T cells, __________ T cells, __________ cells, ________ cells, ___________ cells, and ___________.
- CD4
- CD8
- Mast
- Plasma
- Dendritic
- Macrophages
Dendritic cells can extend across epithelial cells to retrieve ____________.
- antigens
Dimeric IgA and Pentameric IgM binds ____________ at various sites in mucosal tissues to take care of business.
- pathogens
Humans with selective deficiency of IgA do not succumb to infection. Why?
- in IgA deficiency the lack of IgA is compensated for by increased productions of other isotypes (IgM)
IgM and IgA can be transported to the other side with the help of a…
- poly-Ig Receptor
- uses the J chain to safely transport Igs
Intestinal helminth infections provoke strong TH2 mediated immune responses
- feature of CD4 T cell responses to intestinal helminths is that they can polarize, becoming either a protective TH2 response or a TH1 response that augments the disease and discomfort of the human host
- TH2 responses can lead to expulsion of the parasite, whereas TH1 responses lead to persistent infection and chronic inflammation of the intestine
