Immunology - Dr. Grosche Flashcards
(14 cards)
What represents the first line of physical and immunological defense against invading pathogens?
Mucosal immune system
The ___ is the largest lymphoid organ in the body, and has more mucosal ___ (class) antibodies than anywhere else in the body.
Gut, IgA
Three major functions of the GI tract:
- digestion/absorption of nutrients
- barrier function
- appropriate immune responses
Autochthonous flora vs. allochthonous flora
- both indigenous
- autochthonous = evolutionary symbiotic relationship
- allochthonous = some pathogenic potential
3 protective functions of normal gut flora:
- pathogen displacement
- nutrient competition
- production of anti-microbial factors
4 structural functions of normal gut flora:
- barrier fortification
- induction of IgA
- tightening of tight junctions
- immune system development
6 metabolic functions of normal gut flora:
- control epithelial cell differentiation/proliferation
- synthesis of vitamins
- fermentation of non-digestible dietary residues/mucus
- ion absorption
- salvage energy
- production of by-products
Where are peyer’s patches located in the GALT?
small intestine
Where are lymphoid follicles located within the GALT?
entire gut
Functions of the mucus layer
physical barrier, bacterial adhesion, antibacterial peptides, IgA
What happens if something reaches the sterile crypts?
inflammation
The apical junction complex consists of:
tight junctions and adheres junctions
Adherens junctions (AJ) vs Tight junctions (TJ)
AJ = maintain cellular proximity and intercellular communication required for TJ TJ = hold cells together, regulates paracellular permeability, maintain cell polarity
Functions of secretory IgA
- does NOT activate complement, prevents unnecessary inflammation
- binds/neutralizes pathogens and toxins
- limits access of pathogens to mucosal surfaces without risking inflammatory damage
