Lecture - Infection and Immunity (Allergy) Flashcards
Allergy
- Which of the four types of hypersensitivies is this?
- What is the definition of this?
- So it is a type 1 but it is often associated with a Type ____ late phase reaction
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Allergens
So allergies (type 1 mainly but involves type 4) are induced by allergens - what are some examples of allergens?
Of course you shouldn’t memorise this extensively but basically, what are the things can cause an immun response?
-what can you say about penicillin
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Carl Prausnitz came up with three components that allergy requires - what are they?
-what was the experiment that he carried out?
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What are some common examples of Type 1 hypersensitivity? Which one is the worst?
Slide 6
Okay now to talk about the process of allergy
There is the immediate and late phase
- What is the mediator of immediate and late phase?
- What type of sensitivity is the immediate and late phase?
- What’re the time periods of the two?
- Will you get the late response if that’s the first time you are challenged with it?
Slide 7
- Using slide 8, explain what the difference is between when you first get exposed to the allergen to when you get repeated exposure to the allergen
- like, how does the whole process work - explain to a wall - Now with slide 9, what is released by the antigen-activated mast cell and what are the consequences of that?
So basically, when you are first exposed, the allergen will be taken up by the APC and presented on MHC-II to the niave CD4 T cell, which will receive a certrain mix of cytokines from the APC to then differentiate into T helper 2 cell and this will provide cytokine help (IL4 and IL5) to B cells to then produce IgE (class switching occurs, I guess). And that IgE will then go bind to mast cells and the mast cells will be ready for the repeated exposure. When there is a repeated exposure, the allergen’s antigen will bind to the IgE on the mast cells to degranulate and they will release inflammatory mediators like histamine which will be involved with the immmediate type 1 hypersensitivity action. It will also release cytokines which wil be involved in the late ohase reaction
What are the main features of an inhaled allergen that may promote priming of TH2 cells that drive the IgE responses?
- for each of the 7, why are they good at driving the IgE response?
- what’s the difference between IL-4 producing CD4 T cell annnnnd a TH2? What does IL4 do?
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What does dust mite poo contain? So how does that help it be an allergen?
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Pollen is a major allergen source, what does it often contain?
On slide 13 is the process of pollen leading to an immune response - explain it to a wall xx
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- Okay so in an asthmatic pateint, they have gone through the priming phase (where they were first exposed to the allergen or whatever they had reaction to), so now what does their airway look like?
- What is the pathophysiology for a person who is getting an asthma attack?
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Hygiene Hypothesis
- Why do first world countries have higher incidence of allergies?
- Reduced infection may lead to what? Why is this?
- So explain the hygiene hypothesis
Alright, so slide 16 has a summary. Hygiene hypothesis = denoting a form of allergy in which a hypersensitivity reaction such as eczema or asthma may occur in a part of the body not in contact with the allergen.
So you have some genetic susceptibility to allergic reactions but also the environment plays a role. If you have a hygenic environment and high susceptibility - mroe likely to get allergies that are atopic (aka reactions that occur at sites which arent in contact with allergen. If you are the opposite, you’ll get shit like measels, I guess
Genetic link to allergies
- What does atopy refer to?
- So what are examples of genetic predispositons to allergy?
- gene, nature of mutation and possible mechanism association
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Okay, talk me through the development of an allergy and the desensitisation of it
Mention these words:
- what cell in each situation is used?
- what cytokines are released in each situation?
- what’s the effect of desensitisation on the allergy?
Recite the sticky in the top right corner from slide 19
What are the therapies of asthma, then? He had this in exams
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Slide 21 - explain how specific immunotherpay and prophylactic vaccinations work
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