Cell Mediated and Humoral Immunity III Flashcards
Which recirculates more, B cells or T cells?
T cells
Activation of B cells increases their role as APCs. This happens by upregulation of what proteins?
MHC Class 2, B7-1 and B7-2
Primary function of IL-2
A growth factor for helper T cells and B cells
Primary function of IL-4
Growth factor for Th2 cells and B cells, promotes differentiation of B cells to IgE production. Produced by Th2 cells
Primary function of IFNg
Enhances MHC class 2 expression and promotes differentiation of B cells to some IgG production. Produced by Th1 cells
Phases of antibody responses (4)
Lag phase, Exponential phase, Steady state phase, Declining phase
What is required for isotype switching and what clinical disorder occurs when this is not present?
CD40L binding required. Pts without CD40L expression have hyper IgM syndrome
Isotype switching involves switching from what isotype(s) to what isotype(s)?
IgM to IgG, IgE, or IgA
Which antibody type does IL-4 induce and what does this type fight?
IL-4 promotes IgE production, which fights helminth infections
Switch recombination
Mechanism of isotype switching. Existing VDJ brought next to a new constant region
Affinity maturation involves manipulating BCR antigen affinity. Where does it take place and what is it dependent on?
Takes place in germinal centers, dependent on T cells
Germinal centers are what type of follicles?
Secondary B cell follicles
What do follicular dendritic cells (FDCs) do in germinal centers and what protein do they use to do it?
Trap antigen-antibody complexes on their Fc receptors
What are the functions of T cells within a B cell germinal center?
To promote class-switching and rescue B cells from apoptosis
What does cross linking of the BCR and Fc receptor do?
Delivers an inhibitory signal through the FcR which suppresses the B cell response
