Flashcards
L8 - B cell development
Cards in this deck (54)
- 1what is the purpose of the effector section of the antibodyallows interaction with compliment or other molecules
- 2clinically why are effecter regions of the B cell useful?we can attach drugs or target things to the effector section of the antibody
- 3how do we know that antibodies are a really important aspect of the immune syste,diseases which decrease the number/ effectiveness of antibodies are very severe
- 4why are huge deficiencies in antibody numbers very rare?- because this will kill people off v quickly
- meaning any congenital issue like this would be removed from the gene pool before reproductive age - 5what 2 main receptors are found on B cells which bind to antigen?- the B cell receptor
- the immunoglobulin itself - 6what 2 cell types can B cells differentiate into?plasma cells and memory B cells
- 7what is the purpose of B cells havingMHC2 receptors on their membranes?allows the B cell to activate CD4+ T helper cells which will aid in the B cell maturation
- 8give a few important mechanisms used ny antibody which aid the immune syste,- binds to bacterial toxins
- labelling the surface of pathogens for destruction by macrophages etc
- compliment activation - 9where are B cells first made and then whre are they made in adults?- first made in foetal livers
- then made ion Bone marrow - 10where does the majority of B cell development happen?in the bone marrow
- 11what are the 3 main types of B cellls (not differentiated cell)- B1 B cells
- Follicular B cells
- Marginal Zone antibodies - 12why does B cell activity need to be highly regulated?to prevent autoimmunity and cancer
- 13give the life cycle of a B cell- B stem cell in bone marrow proliferates and differentiates into Naive B cell
- B cell binds to complimentry antigen to activate it
- differentiates into plasma or memory B cell - 14what is the first step in production of. B cell in the bone marrow?B cell precursor rearranges its immunoglobulin genes randomly to give a random receptor
- 15how is autoimmunity prevented in B cell development in the bone marrowq?- negative selection
- host cell antigens are presented to the B cell receptors, if they bind then the B cell is killed off - 16where does negative selection happen for a B cell?in the bone marrow
- 17what chain of the B cell receptor is made first?the heavy chain
- 18specifically which receptor genes are rearranged during heavy chain development?D-J and V-DJ genes
- 19is the light chain formed by the time the heavy chain is presented on the cell surface?no
- makes heavy chain which is presented on a surrogate light chain to the surface... then goes to make the light chain - 20specifically which light chain genes are rearranged during receptor developmentV-J genes
- 21what happens to the light chain once its been formed?its incorporated into the heavy chain to make a complete BCR
- 22what 2 antibodies are present on the first mature B cellIGM and IGD
- 23once both heavy and light chains are formed what happens to gene rearangementits stopped
- 24what is the success rate of BCR gene rearangement?70% failure rate per chain recombination
- 25how does the B cell prevent further gene rearrangement after the BCR is formed?preventing RAG expression and function
(RAG is gene responsible for rearrangement) - 26are both inherited chromosomes recombined for BCR's?yes but one at a time
- 27what is the term for stopping gene rearrangement once the BCR has been formed?allelic exclusion
- 28what are the 2 light chains called?kappa and lambda
- 29what is the ratio of Kappa : Lambda in humans?2-3:1
- 30why does the cell use all potential genes for BCR development?raises chance of making successful BCR
- 31what cells in the bone marrow do B cells develop onstromal cells
- 32what do stromal cells do to aid B cell devlopment- give contact dependant support
- release cytokines - 33what are the 2 outcomes if a B ell recognises host cell receptors?apoptosis
receptor rearrangement - 34in B cells does positive or negative selection happen first?negative selection happens before positive selection
(remove host targeting cells first) - 35how does the B cell undergo positive selection?- if there is need for the B cell itll be given a survival signal
- if not itll die - 36which chain is rearranged in a pro B cell and which is rearranged in a pre B cel?pro-B cell = heavy chain rearrangements
pre-B cell = light chain rearrangements - 37what immunoglobulin is presented by immature B cells?IGM
- 38what antibodies do mature B cells present?any of the random ones + IGD
- 39give the difference in receptors from resting B cells and plasma cells- resting B cells: lots of MHC 2, surface antigen but not IG secretion
- plasma cellss: have low surface IG, has no MHC2, has high rate of IG secretion - 40out of resting B cells and plasma cells which can undergo somatic hypermutation and isotype switching?- only the resting B cell
- this is why the plasma cell loses its MHC2 receptors - 41why does the resting B cell have lots of surface BCR'sto increase chance of detecting pathogen antigen
- 42explain "Plasma cells are terminally differentiated"they cant undergo isotope switching or somatic hypermutation, they are finished maturing
- 43what are the 2 mechanisms of Bc ell antibody responses- T cell dependant activation
- T cell independant activation - 44explain T cell independant- no T cell driven maturation
- some IGM and IGG but little fine tuning of the receptors to the pathogen - 45explain T cell dependant antibody responserecruiting T cells allows cross talk and fine tuning of the antibdoy response
- 46which out of the 2 types of B cell antibody responses produced Memory B cellsT cell dependant antibody responses gives memory B cells
- 47what is the benefit of T cell dependant antibody responsethe antibodies are much more specific and gives a much more long lived response
- 48why are vaccination programs given to young children?because their T independant responses are poor
- 49where does T dependant antibody response begin?in germinal centres such as in lymphoid tissue and the spleen
- 50what are the 2 sections of germinal centres- the follicle
- the T zone - 51what are found in the follicles and the T zones of germinal centres?- T zones are just T cells
- follicles are B cells - 52give the full life cycle of a B cell
- 53another helpful diagram
- 54—
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- Year 2 I&I. Flashcards on L8 - B cell development, created by Jack Rowe on 21/12/2022.
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- Jack Rowe · Dec 2022
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- Dec 21, 2022
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