lecture 6 Flashcards
true or false: a majority of the parasites are poop transmitted
false they are soil transmitted
what are the 3 classes of parasited
-tapeworms
-flatworms
-roundworms
which proportion of the parasited do helminths infect
25%
true or false: there are no vaccines for parasites
true
new discoveries due helminths
-Type 2 immune responses
-New epithelial lineages
-New immune cells
-New subsets of immune cells
helminths regulate
-Inflammatory bowel diseases
-Allergy
-Autoimmunity
-Graft versus host disease
Heligmosomoides polygyrus bakeri aka Hpb
Model of human roundworm infection strictly enteric
how does Hpb work
Once inside it gets through the epithelial barrier into cell mucosa where they make granulomas=tissue invasion that will last a week after they are gonna cross back to get into intestinal lumen around the villi where they will lay their eggs lasts 3-4 months
why is the intestine epithelium a barrier
-Prevents the pathogens from getting intoi the intestines into the tissue
-Mucus
true or false intestinal epithelium senses pathogens, release alarmins and danger signals
true
how helminths fight infections
-Antimicrobials, antihelminths proteins
-Weep and sweep for helminths expulsion
intestine has two distinct epithelia, which are:
-The villus
-Crypt
what are the tyoes of cells in the villus
-enterocytes
-Enteroendocrine cells
-tuft cells
-goblet
what do enterocytes do
cells responsible for nutrient absorption
what do Enteroendocrine do
with are important for hormone secretion
what are tuft cells important for
which are important for sensing luminal content
what do goblet cells do
they secrerte mucus
type of cells in the crypt and what do they do
-Paneth cells: secrete antimicrobial peptides and growth factors to homeostatic stem cells marked by the Lgr5+ISCs that are responsible for the self renewal of the epithelial layer that will do that in 3-5 days
-They are always self vew and differentiate into all the different things
-When they get to the top they go through apoptosis
to regenerate the pithelium tissues….
revert into a fetal like state following damage
Following intestinal injury (DSS, irradiation)
-Homeostatic ISC are depleted
-Surviving cells of the crypts undergo a rapid, transient, proliferative boost that replenishes non-functional cells
-The epithelium is transiently reprogrammes into a fetal like state with de-novo expression of fetal jmarkers and suppression of adult stem cell markers
Assesing global transcriptional changes using bulk RNAseq; advantages and disadvantages
Advantages:
o In-depth analysis of the full transcriptional landscape of a specific sample – all poly-A tailed mRNAs in all cells of the sample in a given time oHigh resolution – by choosing how many base-pairs to sequence we control the abundance of low-expressed genes we will detect
Limitations:
o A snapshot of a sample’s transcriptional landscape
o There is no distinction between different cells type in the sample
what does gene set enrighment analysis do
identifies whether a predetermined list of genes is over represented in a large dataset pf genes
-it confirms a getal associated transcriptional signatures in he’s stimulated organoids
Hpb secreted products induce a….
fetal like state on the ISC niche
If you stimulate the cells with HES only then u can
see them express clu and very specific cells in the organoids were expressing them
