B cells and antibodies Flashcards
What are the 2 major regions of an antibody
- Antigen binding region (FAB)
- Fc Region
Each B cell can produce how many BCR’s
Only one- can only produce one antibody
One B cell, One B cell receptor, one specific epitope
What is the part of the antigen that the immunoglobulin on the B cell can bind to
an antigen’s epitope
Where in the body does t-cell independent activation occur
Spleen
What Ig does a naive B cell express
IgM or IgD
Where is IgM found
on naive B cells by defalt
What are characteristics of IgM
-Pentamere, very very large
- Activate complement classical pathway
What is the main immunoglobulin that fights off invaders in blood stream? What happens if this is low in the blood stream?
-IgG
-If low, this is a red flag- means they can’t fight off infections. Immediate consult to immunology
What is a normal serum lelvel of IgG in blood stream
700-1500
Which immunoglobulin passes from placenta of mom to fetus
IgG- only one from innate immunity
- For patients who can’t make antibodies, supplement with replacement
What is the main Ig of mucosal surfaces in the sinus, GI, resperatory, and ear
IgA
What Ig is in the milk of moms passed to newborn?
IgA
What does a low serum IgA mean?
Its normal! IgA should not be in serum- it is in sinus, resp serfaces, and ear.
- If pt has lots of sinus infections/resp tract infections, could be a problem. BUT, probably not problem for IgA without other history.
What are 2 concerns with low IgA
- They don’t make it and their body isn’t making it.
- Their antibodies are attacking IgA, so if they get a blood transfusion it’ll be immediate anaphlaxis, as their antibodies fight it and that’s why its a low level.
Which Immunoglobulin is responsible for anaphlaxys
IgE
Which immunoglobulin is least abundent
IgE
After the first exposure, explain MOA for IgE allergy
- Mast cell binds to IgE(stays bound)
- Allergen binds to IgE on mast cell
- Mast cell degranulates and causes allergic reaction through immune system
Why are people developing allergies?
-We don’t know- not specific gene, not clear reason
-Hypothesis: immune system not exposed enough
Why do you introduce peanuts early to babies orally
- You desensatize the baby to a food orally early on instead of through the skin or in a situation where it’s seen as a concern
What pathogen does IgE kill and relates to
Parasites
Plasma vs Memory B cells
plasma: produces antibodies
memory:long lived memory cells
