9-Immunity by B cells and Ab's Flashcards
A lot of repeats in this chapter from previous chapters objectives. I excluded the repeats. (28 cards)
What are the functions of Igα and Igβ on the B surface membrane?
Their tails transduce the signal of clustering of IgM’s to the inside of the B cell
What is the function of the B cell co-receptor?
it delivers the necessary signals needed to activate a naive B cell when IgM clusters form on the surface.
What is the fxn of CR2 of the B cell co-receptor?
it recognizes the complement fragments on a pathogen
What is the fxn of CD19 of the B cell co-receptor?
acts as the signaling chain of the receptor
What is the fxn of CD81 of the B cell co-receptor?
Unknown, but it does act on HepC cell surface receptor
What special type of Ag’s that B cells can react and activate to without the activation from T cells?
Thymus Independent (TI) 1 and 2
Where does the stimulus come from for TI 1 Ag’s?
They come from innate immunity products like bacterial LPS.
What types of stimuli are TI-2 Ag’s?
They are repetitive carbs or proteins present in high density on the microorganism
How does TI-1 Ag’s activate the B cell?
Basically it’s a bunch of signals from innate immunity- TLR4, BCR’s and co-receptors
How do TI-2 Ag’s activate the B cell?
They act by crosslinking BCR’s and co receptors
What are the 2 main functions of IL-4?
It not only causes growth and proliferation of T cells to TH2 cells, but stimulates B cells when they are activated from TH2 cells
Which cytokines from TH2 cells influcnce the B cell to become a plasma cell?
IL-5 and IL-6
What to centrocytes in the germinal centers compete for on the follicular dendritic cell?
Ag displayed by the FDC
Why must a centrocyte bind the Ag from the FDC and interact with the TH cell to survive?
As centrocytes compete with each other, the ones that find a match and bind are prevented from undergoing apoptosis.
Which type, either plasma or resting B cells, have surface Ig’s?
Resting B
Which type, either plasma or resting B cells, have surface MHC-II?
Resting B
Which type, either plasma or resting B cells, secrete high amts of IG’s?
Plasma
Which type, either plasma or resting B cells, are capable of growth, somatic hypermutation and isotype switching?
Resting B
Why do immunodeficient pt’s have hyper IgM syndrome?
B cells need T cells and their CD40 ligands to undergo isotype switching from IgM to other Ig’s.
What is injected to give passive immunity?
Preformed Ab’s, antiserum or T cells
How does a baby get it’s serum IgG?
It crosses the placenta from mom
How does a baby get it’s serum IgA?
Boob milk from mom
How does a baby get it’s serum IgM?
Babies make it after birth
What happens to all the Ig’s after birth?
THEY RISE
