B9- Trichomonas II Flashcards
Other than the virulence we discussed eg BV and binding proteins like lpg, virus endocytosis, what else is included in their pathobuology
Phagocytosis of immune cells, bacteria and also host cells eg VEC
Tetraspanin 8 mediated immune evasion from neutrophils
Degradation of iga/complement by cysteine proteases (like eh)
Protease mediated cytotoxicity to epi cells (tvROM1 rhomboid protease)
Binding and deg of ecm
Binding and deg of mucins
Why do higher euk have many duplications of genes
Multicellularity
Since this isn’t the case for ME. Why do they have duplications (explains a lot of the large 60k genes in tvag)
To adapt to their lifestyle, metabolic needs, SAV, adhesion
Eg enzymes with different preferences
Which 2 cell surface repeat proteins were found in tvag but are difficult to study through phylogenetic origin due to repeats
BspA and chlamydia pmp
Where is it suggested they’re from based on blast searches
BspA from prokaryotic origin
Pmp although in chlamydia not sure where the origin is
Which periodontal pocket bacteria found to have BspA
Tanerella forsythensis and treponema denticola
Why are repeat containing proteins usually indicative of protein-protein interactions
Variation of repeats can alter binding
What else are they indicative of particularly for host prasites not free living
Usually length of repeats and protein length associated with pathogenicity
Also important for antigenic variation and protein evolution (eg vsp containing repeats)
What do repeat containing proteins mediate binding of in T and T because bspA are adhesins
Epithelial cells and Ecm eg fibronectin from tissue
Why are they important for periodontitis pathogenicity
Biofilm formation between T and T connections
What sort of immune responses do they trigger
Ab and innate response
What are pmp associated with
Also binding human epi cells and also for ab responses and antigen variation/switching
Due to gene duplications, how many BspA and pmp in tvag
Over 900 BspA and about 48 pmp
Explains structure of bspA
Most have a signalP
Leucine rich treats LRR
Some also have TMD
Explain structure of pmp
Also sometimes have sp,tmd
and pmp have repeat motifs fxxn and gga followed by either (I,L,V)
Vary in length for each family member
Why is it suggested the lgt came from common ancestor/ bspA and pmp important for trichomonads role
Most spp (eg gallinae and tenax) have bspA but sligjtly diff (duplication events) - diff number of repeats
Which Lrr subfamily only one found in all lineages (bac, euk,arch) - most are lineage specific LRRs
TPlrr
Give examples and what they have in common
Trichomonas, EH, ruminococci,
All mucosal surfaces suggesting importance at mucosa like it has for Tanerella and treponema
(Remember giredii when sequenced also had BspA but the origin phylogenetically is unknown)
How do gene duplication events cause changes in BspA
Number of repeats/length of repeats
Also affected expression levels of these proteins
(Eg BspA 625 highly expressed)
What evidence is there that gene fusion events occurred between some parts of pmp and BspA
Alignment found similarities in both TMD and the cytoplasmic tail
Within the cytoplasmic tail for NPX motif and also acidic clusters in both types of proteins
What are npx and acidic cluster indicative of in yeast and humans and why might this be important
Endocytosis
Potentially endocytose their surface proteins for mediating endocytosis of host material/ cells (alongside Rab gtpases)
In the 30k fenes transcribed , are pmp and BspA like most LgT (looked at transcriptomics)
Yes
Also Proteomics data Comparing low binding and high binding strains, are there particular bspA and pmps and other surface proteins associated with each. And was this replicated ? - established the functional relevance in TV
Yes there were differences in protein exp for strains
When confirming this in adhesion assays using VEC found
Specific pmps majorly and BspA too important for binding capacity
What is the advantage of dual transcriptomics profiling with tv incubated with mg or mh (margarita 2022)
Can detect genes differentially expressed in their presence
How many were differentially expressed or regulated when comparing tv alone to the tv with Hominis, giredii or both together
6000 genes
What proteins associated with pore forming and potentially hemolysis of rbc/ cells in general upreg in mycoplasma presence
Saplip proteins
Give another example of proteins differentially expressed eg upreg or downregulated (margarita 2022)
BspA and other surface proteins from the proteomics paper to be found majorly in adherent tv strains
(Margarita 2022) Experimental data with hela and oral keratinocytes showed increased binding up to how many fold with mh/mg presence (makes sense from previous flashcard) - correlates with the transcriptomic data
10fold
Why would this make sense for Hominis
Can be directed by carriage of t Hominis to the cell since it is an obligate symbiont
Give example of genes upreg for energy metabolism/better energy source in mh/mg presence (margarita 2022)
Enzymes for TCA cycle generating energy
Enrichment of detoxifiting enzymes detoxifying what in presence of mh/mg in addition to the effect they have on NO
Ros detoxifying enzymes = immune evasion
What else was upreg for better energy/growth of tvag in their presence
AA catabolism ability eg threonine
How many genes associated with more adherent strains from the proteomics surface protein study were upreg in mycoplasma presence including the 2 pmps mentioned before
8/11
What are exosomes which were confirmed in tv by bioinformatics
Microvesicles formed within a mvb which fuses with membrane to release exosomes which can then enter other parasites or host cells
What things can they contain (virulent cargo) according to purification then proteomic findings
Cytoskeleton proteins like RAB gtpases (found in tv for phagocytosis and endocytosis properties) , metabolic proteins like metallopeptidase, bspA
If an adherent strain BspA is released from within exosomes, what can this do - found through incubation of low adherent g3 strains with exosomes of high adherent
Cause better adherence to other low adherent strains eg G3 tvag
What other microvesicles found and how are they released and why are they important/ some virulence factor cargo
Microvesicles released also by mvb or by blebbing of the membrane
Also bspA, peptidases (cysteine and metallo) , RAB,
How is it suggested exosomes modulate immune responses for immune evasion
Induction of il6 and il10 which suppressed other proinflam cytokines
Downregulated il8 which is important for initial clearance
- trogocytosis by neutrophils
Explain how pf13402 domain found in trichomonas before domain even annotated in database
BlastP search on trich sequence
Found homology with many other microbes on mucosa like EH, bacteroides
Decided to name it pfam13402
What motif was the conserved one with the other proteins from other microbes (95% of proteins aligned)
Hxxh motif - gluzincin metallopeptidase domain (m60 family)
What family rich eith zn metallopeptidase sis this motif conserved in
Gluzincin-like family of ZN metallopeptidase
What sort of alignment showed eventually a hit with enhancin which is a viral protease with this sort of motif
Profile-profile alignment
What other motifs do hxxh containint proteins got in host microbes but ultimately differ between each species
Cbm, bacon (both carb binding)
The protective glycocalyx is made up of mucins and what
Proteoglycans made up of GAGs like heparin sulfate
What happens on pul78 hypothetically
This bt4244 binds terminal gal with sgbp also on surface
Processing and import via susC/D
O-glycan peptides further processed by periplasmic gh2 (b galactosidase) and gh109 galnacdase
Import through IM to cytosol where it encounters galnac kinase
What domains does the pfam13402 containing have in g3 tvag
A tmd
And pa14 domain (instead of cbm etc)
How does this pa14 domain bind glycocalyx
Binds heparan sulfate PG via their gag
Overexp of this protein did what
Induced cytolysis of cells - likely through damaging the glycocalyx glycan barrier of cells
Allows the tv proteases like tvROM1 to cause cytolysis
What does this new target indicate
In addition to other cell surface proteins like bspA,LPG, have this one with binding capacity
Could potentially introduce competitive binders to heparan PG?
Degradation of iga is through cysteine proteases on tvag, what else degraded with these
Ecm
Does the pa14 domain containing target mucins or just hspg?
Hspg
Do tvag have more m60L containing other things like cbm
Yes they have over 20
Studies have found which way neutrophils kill tv or try to important
Trogocytosis (not full phagocytosis but nibbling through neutrophil proteases)
Why would the fact t vag has cysteine proteases for
Iga degradation (as well as for ecm, tj etc) affect this
Studies show that adaptive immunoglobulins are vital for trogocytosis
Overexpression of ROm1 rhomboid protease increased attachment and cytolysis of which types of cells (key virulence factor)
Ectocervical cells
Which tv BspA using rt PCR was expressed quite highly In comparison to others when in contact with ECM. How was this specific BspA confirmed to be expressed on surface during infection by the same group investigating expression
BspA 625
Found expressed using immunofluorescence
Given the evidence for BspA mediating adherance eg through adherance assays on VEC/ proteomic presence in high adherent strains. What types of things are they hypothesised to bind and also other pathogenic events likely mediated by them
Host cells, bacteria, viruses,
Could potentially mediate endocytosis and phagocytosis too
Which other protein from other lecture was found to be important for immune evasion AND ALSO FOR ADHERANCE!! Like the surface proteins in this study
Tetraspanin 8
Amoeboid transitikn also associated with better adherance aswell as tsp8. What protein has been identified for this host-cell adherance/ pathogenicity
TvFim1 (fimbrin protein) - trich have their own actin complex so this allows cytosketelal remodelling
What does TvLPG bind (first host receptor found just before the heparin sulfate example)
Galectin 1
