IMI3: the adaptive immune system Flashcards
what are the 2 key consequences of the adaptive immune system?
recognise pathogens specifically
memorise pathogens’ characteristics
what are antigens?
part of a molecule recognised by an adaptive immune protein
what are the 2 key features of adaptive immune system?
specificity and memory
does the adaptive immune system have both humoral and cell mediated components?
yes
what are the humoral components of adaptive immunity?
antibodies that circulate in the blood perfuse tissues and are secreted onto mucosal surfaces
what produces antibodies?
B cells
what are the best characterised lymphocytes?
conventional T cells and B cells
what is the primary lymphoid organ for T cells? for B cells?
thymus
BM
what are naive B and T cells?
B and T cells that didn’t encounter an antigen upon encounter with an antigen
what happens to T and B cells after they are activated?
they are going to become effector and/or memory cells
what are the 2 functions of T cells?
support function: helper T cells
effector function: cytotoxic T cells
what does B cell produce?
immunoglobulin/antibodies
what are immunoglobulin?
molecules that bind highly specifically to foreign antigens
do all B cells produce the same immunoglobulins?
no. they each produce a unique immunoglobulin with a narrow specificity
what do naive B cells express?
membrane bound form of immunoglobulin called B cell receptor (BCR)
what are plasma cells?
effector B cells that produce only antibodies but lack BCR
can B cell act as an APCs?
yes
do B cells express MHC?
yes MHC II
how can they capture and internalise antigens?
through BCR
what are TCR?
T cell receptor that recognise antigens but ONLY when the antigen has been chopped up and held by an MHC molecule
what is another name for T helper cells? what do they do?
CD4–> important functions in supporting other cells of the adaptive immune system
what is another name for cytotoxic T cells? what do they do?
CD8–> specialise in killing defective host cells by releasing cytotoxic granules containing granzyme and perforin that can very effectively kill target cells
what are the key players of the humoral adaptive immunity?
antibodies
what are the key players of cell mediated immunity?
T cells