Immunology Chapter 4 – Antibody structure and the generation of
B-cell diversity
Lines of defense
1. Barriers (chapter 2)
2. Innate immune system (chapter 2/3)
3. Adaptive immune system in this chapter
a. B-cell
b. T-cell
Pathogens
1. Extracellular pathogens (bacteria): handled by proteins
that can stick to them
o Innate immune system: complement system
o Adaptive immune system: antibodies that are
produced by B-cells
2. Intracellular pathogens (virus): handled by killing the whole cell
o Innate immune system: NK cells
o Adaptive immune system: Cytotoxic T cell
The helper T-cells will help the B- and T-cell response.
The big difference between B- and T-cells
B cell receptor: recognize intact antigens (proteins, carbohydrates, DNA)
T cell receptor: recognize process (small) antigen that is presented in
MHC by dendritic cell
B cell: recognition and effector molecules (plasma cells) are identical:
BCR-antibody
T cell: recognition and effector molecules (cytokines) are different:
TCR-cytokines
The structure of antibodies
5 classes of antibodies differ in their constant region
1. Immunoglobulin G (IgG): most common antibody
a. 4 different subclasses (IgG1- IgG4)
2. Immunoglobulin M (IgM)
Extra domain in constant region and less flexible hinge region
3. Immunoglobulin D (IgD)
4. Immunoglobulin A (IgA)
a. 2 different subclasses (IgA1-IgA2)
5. Immunoglobulin E (IgE)
Extra domain in constant region and less flexible hinge
region
Structure:
- Constant region: close to the membrane
- Variable region: on the top – antigen-biding site. Every
TCR/BCR is different in variable region.
3 variable regions which have high variation in
sequence:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller biomedicalsciencesvu. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.23. You're not tied to anything after your purchase.