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45 Cards in this Set
- Front
- Back
What did HG WELLS show that anaphylactic reactions to various proteins could be inhibited by |
Prior feeding of the appropriate materiai |
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OT is the term thats used to refer what |
The state of unresponsiveness that exists for non pathogenic antigens in the gut lumen |
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What immunity can ot be induced to and whats easier to tolerise |
Both humeral and cell mediated immunity Cell mediated immunity is easier to tolerise they require less antigen and last longer |
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What is easier to tolerise Th1 or Th2 |
Th1 |
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What type of antibidy responses are extreemly sensitive to OT |
IgE |
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What does OT induce in lymphocyte homing |
Defective lymphocyte migration |
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What is required for the maintence of OT |
Antigen persistence |
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What are the easiest to tolwrise because they are most associated with pathology |
IgE and DTH |
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Induction and maintenance of OT FOR ACTIVE IMMUNITY VS TOLERANCE particulate Viable Locally invasive Pp uptake T independent |
Soluble Non living Rapidly absorbed Mucosal uptake T dependent |
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Is it good id you introduce the antigens early? |
Yes |
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What happens ir the animal is very sterile |
Will be resistant to tolerance |
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What does poor nutrition do to OT |
Decreases OT |
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What is clonal deletion |
Getting rid of self reactive t cells |
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What is Fas deficient mice and what is their tolerance |
Fas means they cant apopotose cells and keep proliferating Their tolerance is normal so apoptosis isnt mechanism in oral tolerance |
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Is there a single mechanism for ot |
No |
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What is clonal anergy |
T cell knows a antigen is there but not getting excited enough so dont make an immune response |
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In clonal anergy are t cells recognising the antigen |
Yes but dont see it as inportant and dont do anything Lack of co stimulatory molecules and antigen presentation |
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CD8 regulatory or suppressor T cells mediated OT as the induction of tolerance could be prevented with what |
Cyclophosphamide |
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What cytokines are enhanced following oral tolerance |
Il-10 and TGF-β |
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What happens if you block tgf-β ? |
Block oral tolerance |
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What is bystander suppression |
Associated with feeding low doses of Ag Lacking co stimulatory molecules |
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What do you need to tolerise for autoimmune antigens |
There are multiple auto antigens Only need to induce OT on one to tolerise them all |
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What happens with oral tolerance and skin grafts |
If induce oral tolerance they will down regulate the inflammatory response related to the skin graft |
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What happens when you deplete CD4+ cels |
This prevents oral tolerance |
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What is increased following oral tolerance ( T cells subset) |
Th2 increasesd and Th1 decreased |
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What can OT be transferred by |
CD4 cells γδ CD8+ T cells- this suppresses igE |
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Diabetes in NOD mice can be prevented by what |
A transfer of tolerised CD8+ γδ T cells |
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What happens when γδ T cells are depleted |
Prevent oral tolerance |
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Can oral tolerance be induced in TCR KO MICe? |
No |
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What do γδ T cells play a important role in |
Intestinal homeostasis |
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What happens to oral tolerance with APc functions activate |
Oral tolerance is prevented Activated APC express co stimulatory molecules that will present the antigen and break the OT |
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Epithelial cells express MHC CLASS II but have low levels of what |
Co stimulatory molecules and ICam-1 |
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What do antigen loaded DC DO |
found in efferent intestinal lymph after feeding (draining to the gut in feeding) they are likely to induce oral tolerance they have low levels of co stimulatory molecules |
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What happens when antigen passes through the gut |
Converted and changed Ag passing through the gut makes it more likely to induce OT rather than being injected |
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Can OT be induced in IL-4 KO mice |
Yes |
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IL-10 KO MICE develop what |
IBD |
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What cytokine is suppressed by ot |
IFN-γ |
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OT OF IGE is dependent on what |
IFN-γ |
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What happens with IFN-γ KO MICE |
Ot is normal |
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Bystander supression is dependent on what |
TGF-β |
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Oral administration of antigen then to the GALT - high dose |
Deletion anergy of Th1 and Th2 Clonal deletion and clonal anergy Oral tolerance |
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Oral administration of antigen then to the GALT - multiple low doses |
Induction of Th2( IL4/IL-10) induction of TH3( tgf-β) Active supression Oral tolerance |
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What augments oral tolerance |
IL-2, IL4/IL-10 anti-IL-2 cholera toxin B subunit LPS IFN-β Multiple emulsions |
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What decreases oral tolerance |
IFN-y Il-12 Cholera toxin Anti-MCP-1 Anti-γδ Cyclophosphamide Graft versus host disease Parasite infection- if infection u up regulate the co stimulatory molecules |
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When can OT be a problem? |
Developing oral vaccines- against mucosal pathogens is desirable u dont need neddles which is expensive painful |