Mucosal Immunity Flashcards
Does the epithelium have tight junction?
Yes
What does MALT means
Mucosa associate lymphoid tissue
Locally homed T and B cells recirculate where?
Where they first encountered antigen
Weldeyer’s ring is an example of what site
Effector
There are two types of lymphoid structures what are they (sample environmeny Peyer’s patches)
There are scattered lymphoid cells (sample environment) (intraepithelial cells) and also there are organised lymphoid tissues (like Peyer’s patches).
What type of Ig is secreted in large amounts post antigen recognition?
IgA
AMP function in mucosal immunity
AMP constantly binds and neutralises bacteria
What regulates the mucosal immune system (type of immune cells (2))
DCs and Macrophages which are tolergenic
What type of highly mobile epithelial cell constantly surveys the epithelium
Intestine epithelial cells (IEL)
Epithelium is quickly self-renewing, stem cell differentiation can lead to:
- Enterocytes/colonocytes: absorptive functions, AMPs production
- Paneth cells: Antimicrobial peptide productions (AMPs)
- Goblet cells: mucus secretion
- Enteroendocrine cells: Neurohumoral secretion.
Paneth cells produce what which forms pores
Alpha beta defensins
Sebocytes produce what antimicrobial structure
Histones
What is the dominant class of Ab on mucosal surfaces
IgA
What IgA type is in lung
IgA1
What class of IgA is in the colon
IgA2
What is the major function of secreting IgA.
I_______ e_________
Immune exclusion
IgA abosrbs through mucus layer thorugh interactions with what
Carbohydrate moieties
What does IgA not activate, also what enzyme are they resistant to
complement classical pathway, don’t promote inflammation, protease resistant.
What type of process is used to produce IgA
Class swithcing
Gut IELs are recognised and lead to the elimination in what epithelial cells
Ones that express an abnormal phenotype resulting from stress or infection
Inappropiate or excessive activation of IELs gives rise to what type of disease
Coeliac
Innate lymphoid cells are the counterpart of what cell types
CD4+ cells
Innate lymhoid cells come from a precursour that also diverts to T/B cells. Is this true or false
True
What receptor don’t innate lymphoid cells have
TCR
ILCs are poised to secrete what
poised to secrete cytokines that respond swiftly to pathogenic tissue damage
In helminth infection what ILCs are produced and what do they produce, cause to cell and increase production of
Example is helminth infection is that ILC2s will produce cytokine IL-13, cell contraction, mucus production to heal the lining.
Distinct populations of DCs sample the mucosal compartment. They generate what type of T cell and how do they home T/B cells
Anti-inflamatory, generate Tregs, imprint homing via retionic acid
Gut homing lymphocytes is via what? And where is it present
MadCAM ;is on vasculature of all mucosa
M cells constantly do what?
Survery the environment and pass onto DCs
Host commebsal interactions are required for what vitamin or what type of acid
vitamin K, short chained fatty acids
Antibiotic overuse leads to what infection
C. diff
What can’t you have an overt inflammatory response to? In gut
Commensals
Commensals down regulate what pathways. How, in two ways?
Inflammatory, via MYD88.
Constantly trigger PRRs, decreasing their senstivity
PPAR-gamma induced in response to microbiota LPS diverys NF-kB from nucleus
What cell type does Shigella invade through
M cells
Toxins and other factors faciliate invasion by pathogens: Give three examples
Toxins and other factors facilitate invasion by pathogens.
Shiga toxin inhibits translation.
C. diff toxin A inactivates GTPase
Rotavirus NSP4 disrupts tight junction.
Th2 responses are to h___ infections, and may be triggered by T____ or IL____
Somehow trigger a type II response: trigger unknown, maybe TSLP or IL-33.
Type II responses lead to expulsion and wound repair.
Give three examples of aberrant mucosal immunity
Crohn’s (NOD2, Atg16L1) sustained microbial-induced inflammatory
Coeliac HLA-DQ2 (binds gliadin)
Disturbance in microbiome-antibiotics C. difficile infection
