2.4 - B Cell Immunity Flashcards
Important cytokines in activation of B cells
IL-4, IL-6 and IL-10
IL-6 and IL-10 play a role in what
the differentiation of B cells to antibody secreting plasma cells
When B cells proliferate, they can turn into
Memory cells and plasma cells
Major antibody secreting cell
Plasma cell
Yes or no for these scenarios with B cells and plasma cells: Surface Ig, Surface MHC class II and high rate of Ig secretion
B cells: Yes, Yes, no
Plasma cells: no, no, yes
Where does the B cell encounter the T cell?
Lymph node
Mature naive B cells goes to primary follicle, which then goes to ___ to look for antigen
FDC
B cell recognizes ___ portion of antigen
native
T cell recognizes ___ portion of antigen
processed
FDC expresses what receptor that C3b can bind to and remain on the cell surface
CR1 receptor
When the B cell and TfH CD4 positive T cells interact, where will they go?
- Some go to medullary cords to differentiate into plasma cells
- Others go back to primary follicle, actively divide w/ the formation of the germinal center
Somatic hypermutation occurs in what region
V region
Describe somatic hypermutation
B cells are trying to end up w/ high affinity antibodies that bind tighter
- If they have low affinity they undergo apoptosis
Apoptosis of low affinity antibodies after somatic hypermutation are engulfed by
Tingible body macrophages
IL-10 and IL-6 specific function
Make antibodies that fight and terminate current infection
IL-4 specific function
- Bring about differentiation into memory B cells
T independent antigen do/don’t require the presence of a helper T cell
Don’t
T-independent antigens contain ___ that provide both signals 1 and 2
repetitive epitopes
Examples of repetitive epitopes
lipopolysaccharides and capsular polysaccharides
Is there class switching in t-independent antigens? Why? What’s the major antibody class?
No, b/c T cells are responsible for class switching and you don’t have T cells present
IgM
Majority of antigens encounter T dependent or T independent antigens
T dependen antigens
cytokines play a role in what in T-dependent response
Play a role in which antibody isotype switching may occur
IL-4 induces ___ production
IgE