Lecture 15 - B cells and antibody production Flashcards
how do we designate and identify B cells and plasma cells from T cells?
on the basis that they express CD19 and CD20, which are not expressed by T cells
adaptive immune cells are ________ specific
antigen
what cells produce anibodies?
B cells and plasma cells
what is the target of vaccination?
adaptive immune cells
true or false, B and T cells work independently of other immune cells
false
what are NK natural killer cells?
are lymphocytes, but dont express CD3 and are not adaptive/antigen specific and are therefore not a part of the adaptive immune system
what does B stand for in B cells?
Bursa from birds
where do T cells develop?
in the thymus
what are the features of B cells?
antigen specific, and so has a receptor that gives it specificity to the type of antigen it can bind to
where are naiive B cells found?
in the blood and lymph nodes
- use blood as a transport system to get from lymph node to lymph node
what do plasma cells do
differentiate from B cells and produce masses of antibodies during and following infection and vaccination
EXAM
what are memory B cells?
long lived B cells that await secondary acitvation by same antigen
true or false, B cells can act as antigen presenting cells
true
where do naiive B cells get activated
in the secondary lymphoid organs
how do naiive T cells activate?
they require the antigen to be presented in MHC and HLA molecules on dendritic antigen presenting cells
General explanation: how do naiive B cells activate?
they do not require presentation of antigens by APCs
- macrophage-like cells carry antigen inside a capillary network in the cortex of the lymph nodes. these cells slow down the process and this gives B cells more time to recognise the antigen
where do the B cells live in the lymph nodes?
B cell follicles in the lymph nodes
where do the T cells live in the lymph nodes
around the follicles in the lymph nodes in the paracortical area (very dense)
describe the overall lymph node structure
- B cell follicles in the cortex
- T cell region is elsewhere, with blood vessels and antigen presenting cells studded within
The _________ _____ are the site at which the antigen or cell debris sticks/is arrested so
lymph nodes, adaptive immune cells can recognise it.
how do naiive B cells activate?
- B cell comes from blood and resides in primary follicle of lymph node
- the BCR receptor on the B cell has specificity that binds full length proteins?
- receptor undergoes conformational changes and signal transduction into cell
- BCR receptor is endocytosed/internalised
- full length protein is cleaved into different epitopes and are re-presented at cell membrane on HLA or MHC II
- migration of T cells towards B cell area and vice versa
- They meet at border and T cell specific receptor for presented epitope binds, and also C40 receptor binds C40 on B cell (both signalling to each other like yep thats correct)
- C40-C40 signals also to T cell to secrete cytokines
after B cell activation, why do they act as an antigen presenting cell via MHC II or HLA?
to signal to follicular T cells, and so they must move into the paracortical area
describe how B cell activation is dynamic
B cells, once presenting an anitgen epitope, must move towards the T cell paracortical area, and T cells from there must move towards the primary follicle
what are thymus dependent antigens?
antigens (bacterial proteins) that are recognised by B cells but require T cell help
