Summary
Summary Chapter 11
- Course
- Institution
This is a summary of chapter 11. With all of my summaries for this course I passed it with an 7,7
[Show more]
Seller
Follow
biomedicalsciencesvu
Reviews received
Content preview
Immunology Chapter 11 – Immunological memory and vaccinationPrimary and secondary adaptive immune response
Primary adaptive immune response: naïve T cells
do not know what to do with the infections. When the T cell see the antigen in the
context of MHC presented by DCs they become activated (3 signals):
Effector cells (short lived, help clear active infection) (antigen dependent)
o Effector T cell
o Effector B cell = Antibody --> short lived
plasma cell
Memory T and B cells (long lived, prevent re-
infection) (antigen independent)
(1 or 2 weeks)
Protective immunity: effector T cells goes down but antibody (short-lived plasma
cell) specific against pathogen is still in the blood and gives protective immunity (2 or
3 months – seasonal protection against e.g. influenza due to neutralizing IgG and
IgA)
Immunological memory: (1 or 2 years)
Memory T cells
Memory B cells
Long-lived antibody level slowly decreases but stay at certain level
--> Ensures protection upon re-infection with previously encountered pathogen.
For pathogens with a high mutational load (during their
lifetime and during their expansion these pathogens
constantly gain mutations) the Im is not always sufficient
(e.g. influenza virus uses the inhibitor ability of high
affinity IgG)
- During the first infection the influenza virus has 4
different epitopes
- During the second infection the influenza virus has
changed due to mutations the surface expression of the different epitopes. It
now has 3 different epitopes which are all changed
- During the third infection the influenza virus has changed due to mutations the
surface expression of the different epitopes. It now has 2 different epitopes
which are all changed
- During the fourth infection the influenza virus has changed due to mutations
the surface expression of the different epitopes. It now has 1 different epitope
which are all changed
- During the fifth infection the influenza virus has changed due to mutations the
surface expression of the different epitopes. New epitopes are presented – no
longer high affinity IgG available
Secondary adaptive immune response: when the pathogen load increases compared
to immunological memory a secondary immune response is required.
, Memory cells know what to do with the infections and directly activate the effector
cells (only signal 1)
It is faster, stronger and higher affinity because:
1. Pathogen-specific memory cells outnumber naïve cells
2. Memory cells are more rapidly activated compared to naïve cells: because
they have only to undergo signal 1 and not signal 2 and 3 --> faster
3. Memory B cells already undergo isotype switching to generate production of
high affinity IgG/IgA/IgE + during secondary response naïve B cells are
inhibited and this inhibit formation of low affinity
antibodies --> stronger & higher affinity
During primary response naïve B cells become:
Plasma cells with low affinity IgM
Form a germinal centre with T cells
o Memory B cells
o High affinity plasma cells IgG, IgA and
IgE
During secondary response we already have the memory B cells which are
10-100x more pathogen-specific than naïve B cells. The memory B cells:
Undergo isotype switching to generate high affinity plasma cells IgG,
IgA and IgE
Will form a new germinal centre and undergo affinity maturation:
somatic hypermutation and again isotype switch. They differentiated in
even higher affinity plasma cells IgG, IgA and IgE
Inhibition of naïve B cells is initiated via activation of the inhibitor receptor
FcyRIII --> FcyRIII bind to IgG --> initiated inhibitory signals to naïve B cells -->
no production of low affinity antibodies
Affinity and amount of IgG goes up during each infection round
(3 or 4 years)
Memory B and T cell
They provide protection against pathogens for long time due to existence
of a steady memory cell pool: Memory cells see the cytokines IL-7 and IL-
15 --> memory cells divide --> go to the quiescent pool, some die of
apoptosis and these will be replenished by the dividing memory cells
B cells
Memory B cells can be distinguished from naïve and effector B cells:
Membrane bound vs secreted immunoglobulin
Membrane receptor IgG vs membrane receptor IgM and IgG
Round morphology vs different morphology with more intracellular
compartment
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.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
56326 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now
Recently viewed by you
