Exam 3 - German - Mucosal Immunity Flashcards
What are the 3 compartments of mucosal tissues?
Epi
- Gamma:delta T cells
- CD8 alpha:alpha T cells
- Memory CD8 T cells
Lamina propria
- Lymph tissue
- Gamma:delta T cells
- CD8 T cells
- CD4 T cells
- Plasma cells and B cells
- Macrophages and dendritic cells
Mucosal-associated lymphoid tissue (MALT)
-Lymph node-like organization
T/F - Mucosal infections do not follow the traditional (classical) inflammatory cascade.
TRUE
Tell me the classic inflammatory response to an infection.
Bacteria introduced
Macrophages make inflammatory cytokines
Cytokines released by macrophages produce inflammation
Infection terminated leaving damaged/distorted tissue for repair
Repaired and healthy tissue
Tell me about the mucosal immunity response.
Bacteria access lamina propria via endocytosis
Macrophages activated BUT inflammation is not caused
Effector cells respond and DC go to lymph node and activate adaptive immunity
B and T cells colonize the infected area
Infection is terminated w/ minor tissue damage or no need for repair
T/F - Most mucosal infections are cleared w/o an inflammatory response.
TRUE
When does inflammation occur in mucosal immunity?
IF infection is severe, persists, and/or causes tissue damage.
What are 3 unique features of mucosal surfaces?
Anatomy
-Specialized antigen-uptake mechanisms (M cells in Peyer’s patches)
Effector mechanisms
- IgA antibodies
- Memory T cells
Immunoregulatory environment
- Downregulation of immune responses
- Inhibitory macrophages and tolerance-inducing DCs
T/F - Mucosal surfaces have unique microbiomes.
TRUE
T/F - Oral microbiome is diverse and changes w/ disease.
TRUE
During periodontal health, there is ______ diversity and richness of the oral microbiome.
During periodontal disease there is ___________ diversity and richness of the oral microbiome.
LOW
HIGH
T/F - The microbiome is constantly shaped at the mucosal surfaces.
TRUE
The microbiome influences CD__ T cell differentiation.
4
______-__ is prominent at mucosal surfaces.
TGF-Beta
TGF-Beta + no inflammatory cytokines = ?
TGF-Beta + inflammatory cytokines = ?
Treg
Th17
T/F - Treg cells inhibit mucosal inflammation.
TRUE
What 3 things do Th17 cells do?
PMN recruitment
Antimicrobial peptide production
Tissue repair
What 2 ILs are released by Th17?
17
22
IL-17 and IL-22 have what 3 effects?
Regulate tight junction protein expression
-Maintains barrier integrity
Induce antimicrobial peptide production
- Beta-defensins
- Cathelicidins
- Lactoferrin
Induce PMN chemokine expression
**Too much of Th17 results in what?
**Too little of Th17 results in what?
Overgrowth of bacterial communities - PERIODONTITIS
Overgrowth of fungi - ORAL CANDIDIASIS
Tell me more about overgrowth of bacteria.**
*Increased IL-17 signaling corresponds to increased disease severity
Too many PMNs (so much that bacteria use the PMNs as a food source)
Chronic inflammatory cytokine production
Osteoclast activation
Tell me more about the overgrowth of fungi.**
Persistent fungal infection of the skin, nails, and mucous membranes
Deficient IL-17 signaling*
Causes
- Deficient IL-17 receptors
- Impaired Th17 differentiation
- Impaired Th17 development
Ig secretion plays what 4 roles at the mucosal surface?
Pathogen neutralization
Toxin removal
Antigen browsing
Shapes microbiome
*Mostly IgA
T/F - Mucosal antigens are constantly browsed.
TRUE
What cells:
-Actively direct immune responses
- Express TLR and NOD receptors
- Form inflammasomes
- Phagocytose mucosal bacteria
- Express cytokines and antimicrobial peptides
- Induce local immune responses
???
MUCOSAL EPITHELIAL CELLS
T/F - Epithelial damage can promote mucosal inflammation.
TRUE
What 2 inflammatory responses occur when established pathogens illicit them?
Pathogen evades mucosal immunity
Local macrophages and DCs are activated
- PMNs recruited
- Th17 and Th1 response
