Intro To Mucosa Flashcards by Anna Safrankova

Name the 3 major tracts covered by mucosa surface

Gastrointestinal tract (mouth down to anus)

Uro genital tract (genital and urinary organs eg uterus, bladder, vagina)

Respiratory tract (upper and lower)

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What defines mucosal surfaces

Epithelial cells sexreting mucus

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What is the human - microbiota together called

Supraorganism , they act together

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What tpyes of environmental impacts can affect microbiota configuration either eubiosis or dysbiosis

Antibiotics
Other parasites/pathogens
Diet

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How many cells in the supra organism

100 trillion microbiota cells

10 trillionnown cells (more microbiota)

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What 2 effects do microbesbhave in supraorganism

Release bas things such as toxins OR good things like metabolites (vitamin K, SCFA)

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Give an example how dysbiosis occurs theough environmental pressure

Antibiotics will reduce biodiversity, biomass, and increaae pathobionts like c difficile because leas competition

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What makes up microbiota

Viruses,bacteria, euk microbes, fungi

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Diff parhogens eg bacteria and viruses interact, give some examples

Herpes simplex allows bacterial resistance

Virulence susceptibility due to bacterial presence

Helminths cause autoimmune disease resistance

E coli and e hystolytica increase virulence of eukaryotes

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What cells mostly reaide on mucosal surfaces (MALT)

Immune cells 2/3 of them

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What are the 2 functions of mucosal surfaces

Exchange with outside eg breathing, feeding/digestion , reproduction

Form barriers to chemical or biological insults

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What helps modulate rhe 2 functions

Epithelial cells and microbiota eg the microbiota xan change exchanhe rates

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What are the primary mucosal defence systems

Immediate innate defences -

Mechanical - tight junctions,mucus

Chemixal - amps, lactoferrins, lysozymes, mucus

Microbial - h2o2, lactic acid, bacteriocins

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How do microbial defences work

H2o2 provides protection from candida

Lacric acid from giruses like hiv

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What is the secondary defence

Induced innate (after infection)

More amps, cells like macrophages, mucins

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What is the last tertiary defence system

Adaptice - immune cells and sIgA

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How does microbiota affect all defence syatems

Modulates them at all levels

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What 2 major effects regarding immune system can microbiota have to induce health/ atop inflammation

Reduce ige th2 rwaponse

Increase t regs

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What is the gut lung axis

Where healthy microbiota in intestines/gut can induce LOCAL immune responses eg scfa secretion

Then disturbance/infection/diet/drugs

Change microbiota, change in immune system

Form chronic inflammatort diseases in gut and lung

Can form chronic inf

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Where is stratified epithelial (multilayer) seen

Skin, oral mucosa and vagina

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Where is simple single layer epi seen

In all 3 tracts

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How is microbiota composition studied

16s rrna sequencing

Metagenomics of whole populations

Detect changes in microbiota from helath to disease

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What 3 effects do microbiota in gut have not to do with immune function

Detoxification of eg xenobiotics

Biosynthesis of vitamins like K

Metabolic effects eg insoluble fibre to SCFA for energy and immune function

What is the indirect and direct parhogenic protection by microbes

Indirect - via innate and adaptive immune system eg peyers patch induction, t cells and iga

Direct - attack pathogens via toxins etc or through crowding for nutrients

What 3 things do goblet cells produce

Mucins Trefoil peptides Relm - b Mucons and trefoil make mucus

Which cells produce amps, lectins and cytokines in mucosal barrier

Paneth

What do leukocytes and stroma cells do in mucosal barrier

Regulate sexretory cell differentiation and activation and modulate epithelial cell function eg iga secretion (producing secretory molecule)

What modulates all cell types

Microbiota

How does microbiota affect goblet cells

Affects differentiation division and sexrwtion Also glycosylate mucins

What do secreted molecules in barrier have impact on

Composition of microbiota

What 2 things protect from microbiota and parhogens

Mucins and amps

How do amps work

A, b or theta defensins ``` Secreted by paneth They have microbiocidal effects Work in low conc Can also kill enceloped viruses Constitutivelt expressed but increased in pathogne presence ``` Works by disrupting membranes

Which cells secrete mucins in stomach

Foveolar cells (goblet in small and lathe intestine)

Are mucins always sexreted

Noncan be memrbane bound too

What are rhe 4 major epithelial cells in intestine mucosa

Goblet(mucus), paneth(amps)entero- endocrine cells (hormone) and absorptive epithelial cells (cytokines)

What is the gap between villi called

Crypt

What stem cells are what all epithelial xells from

Lgr5 marked stem cells (smith 2013)

What happens to the epithelial cells

Shed and self renew back from new lgr5 stem cells in the crypt

What is the underlayer of connective tissue below epithelila xells xalled

Lamina propria

What immune cells reside the most in lamina propria

A4:b7 integrin t cells and ccr9 t cells (usually CD4)

What cells usually are intraepithelial

Cd8 wirh ccr9 and aE:b7 which binds e cadherin (smith 2013)

What are the 4 thpes of prr on cells like macrophages, dendrites which detect parhogens

TLR Rig 1 like RLR Nod like C type lectin CLR

What do c type lectin receptors (cell surface)detect

Glycans from fungi or bacteria walls

Where are TLR

Membrane or endosomes

What can tlr induce

Mapk , nfkb, irf

What are the 3 nod receptor classes

NLPRs (recofnise all pathogen pamps) Aim2 (bacteria and viral dna) Nod 1 and 2 (peptidoglycan)

What does rig like 1 detect

Viral rna

How do Rig signal and what

Via mavs mitochondrial adaptor protein Triggers antiviral reaponse eg ifn a and b

For what type of parhogen are amps and iga good for

Extraceullar surfwce pathogens wg neisseria , strep, albicans

What type of pathogens seen on resp tract

Mycobacterium tb Strep Influenza

What thpe of pathogens seen in GI tract

H pylori, salmonella typhi, vibrio cholerae

What type of pathogen in genito urinary system

Neisseria gonorrhoea, hiv, herpes simplex

Points in (clemente 2012)

Twins share only around 50% of same microbiota taxa During first weeks of birth, tlr are not active to build microbiome Lack of microbiota resulta in teduced iga secretion

What did (khoruts 2010) find

C difficile facal transplant increased bacteroides from a deprived bacteriodetes and firmicutes patient The bacteroides reduced CDAD symptoms

What did (de filippo et al 2010) find

Burkina faso populations with high fibre diets found to have much more bacteroidetes than the uk More baxteria of the prevotella genus (phylum bacteriodetes) because they have genes for cellulose hydrolysis = increased scfa

Give an example of c type lectin receptors

Dectin 1 which recognises 1,3 glucans from fungi