3. Humoral immune responses- activation of B lymphocytes and production of antibodies Flashcards
Overview
where do Ag-responsive B-cells develop?
how is the humoral immune response initiated?
how activate mature naive B cells?
how many Ab- secreting cells per week from 1 B-cell?
phases of humoral immune response
General steps and outcomes of B-cells
primary vs secondary immune response
chart?
Primary and secondary immune responses
difference between two?
levels of IgM vs IgG
How is Secondary different?
B cell subsets
Types of B cells
T-dependent vs independent
respond to what Ag?
locations
what Ab produced?
B1- B cells arise from fetal liver by 8th week
B-1 cells can represent a transition of what?
In order to initiate Ab responses, Ags have to be what?
Transported to the B cell areas of the LNs and spleen
Ag capture and delivery to B cells
What type of B cell?
what type is most mature naive B cells?
what do they do for movement?
where do they reside?
what chemokine guides them?
what secretes this?
Ag capture and delivery in LN
What routes?
Ag delivery to Follicular B cells
Are Ags processed?
Small Ags delivery?
Larger Ags?
Properties of FDCs
What do they not express?
what normal function dont they do?
What unique thing do they do?
how do they bind Ags?
what do they play a key role in?
Anatomical Localization of Cells in Marginal Zone
what are the most distinctive cell types in the MZ?
how do Lymphocytes and DCs enter the white pulp?
what forms the basis of the marginal zone?
What can shuttle Ags for follicular B2 B cells?
how does this happen?
What happens once it has shuttled the Ag?
Ag capture in the spleen
what conformation are Ags in?
how are Blood-Borne pathogens captured?
what are they delivered to?
what captures polysaccharide Ags in the spleen?
Ag-induced cross-linking of BCRs and signaling induces several cellular responses including:
B cell Ag receptor complex
what is the BCR?
Naive mature B cells express what?
Class-switched cells and memory B cells express?
what is the signaling part of the complex?
What regions do these parts have?
What are the main B-cell Co-Receptors?
What do these co-receptors do?
BCR signaling
Whats Signal 1?
Whats Signal 2?
If activating what does signal 2 cause?
The steps of BCR complex signaling
Complement receptor 2 in B Cell activation?
what is the CR2 complex?
what causes opsonization?
Once bound what does this do?
in Complement receptor 2 what does CR2 bind and what does Ig bind to?
where does the thing that binds CR2 come from?
what makes up the B cell coreceptor complex?
what does CD19 do?
TLRs and B cell activation
what do the ligands for TLRs activate?
how does it have to do with vaccines?
bridge adaptive and innate immunity
functional consequences of Ag-mediated B cell activation
B Cell Ag presentation to T cells
mechanisms of T cell-mediated activation of B cell
1.
2.
3.
4.
Follicular Helper T Cell
generation steps?
what is main secretion?
what does this cause?
what else can they secrete?
induction of T(FH) cells
What time range?
are they similar to any other T cells?
what is critical role?
what do they express?
Follicular Helper T cells main cytokine secretion does what?
what happens in the germinal center?
what zones are there?
what makes up the zones?
Light zone contains follicular DCs
Mantle zone surrounds GC contains tightly packed small B cells of the primary follicle
in isotype switching what changes?
What stays the same?
isotype switching regulated by what?
Intracellular pathogens?
Helminths?
role of anatomical location
Mucosal tissues in particular?
CD40-CD40L role in isotype switching?
What does this engagement cause?
What process is happening?
Class-switch recombination
takes place where?
what changes?
Affinity maturation
What is the result?
Responses to what only?
what is required for this to happen?
what is changed?
TD- T dependent
what are some of the outcomes of affinity maturation?
Affinity maturation mutations?
rate?
Good?
Affinity maturation
what happens in the progeny of B cells?
up to how many substitutions?
where are most mutations?
more mutations in what type of Ag?
What is needed for survival after mutations?
what does this cause?
what can help them survive longer?
Germinal centers and B cells survival?
mechanisms of B cell survival (affinity maturation)
what mechanisms cause B cell survival after binding to FDC
problems resulting from hypermutations and isotype switching?
Memory B cells?
where are they from?
what helps them survive?
do they stay in lymphoid organ?
Thymus independent responses?
what cause them?
what are their characteristics?
Most TI Ags are what?
what does that mean?
what does it cause?
where do TI responses happen?
what B cells participate?
mechanisms of TI Ab responses.
What type of Ags do they bind?
what are the responses?
What can happen (not the usual) with TI Ab response?
what molecules are used
Protection mediated by TI Abs
what is the major infections prevented by humoral immunity?
example of these?
what do TI Ags help create?
what cells create these?
Vaccine
what will effective vaccines induce?
what needs to be activated?
how is this applied if normally not activated?
what type of vaccine is this?
conjugated vaccines
what creates them
what does it cause
Do conjugate vaccines create a long term protection?
- they produce long-lived protective immunity
- rapid and large secondary responses typical of memory (without much isotype switching or affinity maturation)
inhibition signaling
why do we want this?
what is it mediated by?
recruit and activate what?
INhibitory signaling cascade
What receptor binding can cause phosphatases to inhibit signaling blocking B cell activation?
Ab feedback inhibition and amplification?
under which circumstance can you have either?
FcR and how it causes inhibition? specific mechanism
