HUBS 191 Lecture 36 Flashcards
(36 cards)
where are B cells produced and ‘educated’
in the bone marrow
what are plasma cells
activated B cells that secrete antibody
during cell division of B cells we form plasma cells as well as a pool of self renewing ________
memory B cells
why do we produce memory B cells
these cells live for long periods of time and at the time of a secondary infection they can get stimulated very quickly and start to differentiate into plasma cells and reform memory cells so we never run out
where do adaptive cells encounter antigen
in the lymph node or spleen if its a blood born antigen
when and where do B cells rearrange their BCRs
early in the development in the bone marrow
what are BCRs
B cell receptors are antibody but part of the antibody needs to have a transmembrane domain which anchors it in the membrane
how many copies of its BCR does a B cell have
roughly 100,000
what is the structure of a B cell receptor
two identical heavy chains and two light chains sandwiched together by disulphide bonds
during the generation of diversity in B cells in the bone marrow what portion of the BCR is rearranged
the variable portions of the chain
what type of antibody is most common as a BCR
IgM and IgD
secreted antibodies lack a ____
TM - transmembrane domain
what are the three functions of antibody
neutralisation, opsonisation and complement activation
is antibody soluble or insoluble
soluble so you can have large amounts in your blood and it won’t precipitate out
how do antibodies neutralise microbes
they can bind (non-covalently) to essential structures on microbes or their toxins and stop them from interacting with our host cells
how do antibodies opsonise
they tag the microbe to make them ‘tasty’ for phagocytes
what antibody is the best for activating complement and which pathway does it use
IgM isotope is very good at activating complement via the classical pathway (the most efficient)
what is a native antigen
an antigen that does not have to be processed to peptide
what is another name for an antibody binding site
an epitope
what are the classes of antibody from most to least abundant in the blood
IgG, IgA, IgM, IgE, IgD
what is the function of IgG
opsonisation/neutralisation/activation of complement
what does IgG target
viruses and bacteria
what is the only type of antibody that crosses the placenta and provides passive immunity
IgG
what is passive immunity
when babies are born or in utero they don’t have very good immune systems so they rely on their mothers
