Mucosal Immune System Flashcards
What surfaces do the mucosal immune system protect?
The interior linings such as the GI tract, respiratory tract, urogenital tract, and glands
Why do the majority of pathogens enter the body via mucosal surfaces?
The surface area is massive, and the tissues are permeable and thin
What are mucins?
Mucus is composed of mucins, which are glycosylated polypeptides. Mucins can be cross linked to form larger molecules
What are the secondary lymphoid tissues of the small intestine, and what are their functions?
Peyer’s patches- prevent pathogenic bacterial growth in the SI
Lymphoid follicles
Mesenteric lymph nodes
Villi
Increase the SA of SI, and allow for the lamina propria to extend close to the epithelial layer (route to absorb pathogen to send to lymph tissue)
What purpose to M cells serve?
Transport microbial antigens from the gut lumen to the lymphoid tissues underlying the epithelial layer
What purpose do paneth cells serve?
Secrete antimicrobial substances on the epithelial layer of the GI tract
Why are effector T-cell and plasma cells always present in mucosal tissues, even when there is no infection present?
The mucosal tissues are in constant contact with potential pathogens, therefore the immunogenic cells there are more proactive than reactive.
What does the anti-inflammatory response in mucosal tissues involve?
- Activation of B-cells to produce IgA antibodies
- Activation of T regs
- Activation of some inflammatory T-cells, kept in check T regs
What antibody type is involved in the neutralization process in mucosal tissues?
Dimeric IgA
How are intestinal epithelial cells active players in the immune system?
PRR’s can detect microbial antigens that breach the barrier, and compromised epithelial cells can secrete inflammatory cytokines
