adaptive immunity part 2 Flashcards
where are B and T lymphocytes made?
where are T matured?
where are B matured?
are they present in blood?
where do they accumulate?
what is seen when B and T cells are activated?
bone marrow
thymus - educated to not react to self antigens
in tissues when exposed to antigens
yes
lympoid tissue (MALT, nodes, spleen)
lymphadenopathy
what receptors do T cells use to recognise antigens?
what is the receptor made of?
what does CD3 do?
what does the receptor bind to?
what type of T cell is CD4 what doe they recognise?
what type of T cells is CD8 what do they recognise?
TCRs - T Cell Receptor
variable region (alpha and beta chais), constant region, CD3 complex, CD4 or CD8 accessory molecules
activates T cell
MHC complexes
helper - MHC class II
cytotoxic - MHC class I
what signals are needed to activate T cells?
what other signals are there?
what do CD4 T cells differentiate into?
what do CD8 T cells differentiate into?
signal 1 - MHC binds to TCR and CD3 activates
signal 2 - B7 on APC binds to CD28 on T cell and activates
other:
signal 3: APC releases cytokines and tells T cells what to differentiate into
T helper
cytotoxic
when CD4 T cells are activated what do they differentiate into?
what are the types of T helper cells they can chnage into?
what kind of T cell does IL-12 make?
what kind of T cell does IL-4 make?
what kind of T cell does IL-1 and 6 make?
what kind of T cell does IL-10 and TGF make?
T helper cells
TH1, TH2, TH17, Treg
TH1
TH2
TH17
Tre
what does TH1 do?
cell mediated immunity for intracellular pathogens
activates macrophages
activates CD8 T cells to differentate into cytotoxic cells
stimulates B cells to make IgG or IgA
what does TH2 do?
humoral immunity response fro extracellular pathogens
stimulate IgE from B cells
activate eosinophils for parasites
activates mast cells for allergies
what does TH17 do?
what doe Treg do?
recruit and activate neutrophils
tolerance and immune supression
effector function of CD8 cell?
what helps CD8 cells differentiate?
so what does HIV have to do with this?
kill pathogens with MHC class I in the form of a cytotoxic T cell
TH1 make cytokines
HIV kills CD4
CD4 make TH1
with no TH1 = CD8 struggle to differentiate into killer cells
what 2 proteins do CD8 T cells use to kill pathogens
perforin is released and make a hole/pore in infected cell (virus)
granzyme is released and goes into pore anc infected cell and kills the infected cell
what receptors do B cells have tp recognise pathogens?
what is a BCR?
why can B and T cells both recognise many pathogens?
what do the BCRs recognise?
BCR B Cell Receptor
a membrane bound antibody
combinatorial diversity of genes
antigens: macromolecules (portein,lipid) and small chemicals
hoe to B cells get activated initially?
- antigen binds to BCR
- signal is transducted
- antigen is processed and presented
- MHC is presented on B cell
- TCR binds to MHC(signal 1) and B7 is bound to CD28 (signal2)
- CD40L is released from T cell and binds to CD40 on B cell
- this binding allows the B cell to make IgG (better antibodies)
what antibodies are produced by B cells?
what happens to the affinity of antibodies as time goes on?
what are B memory cells?
IgM = independent
IgG, IgA, IgE is T helper dependent (CD40L needed)
prolonged or repeated exposure = higher affinity
antibodies made and are present after first infectiona nd create a faster stronger response next time round
label an antibody
what is a thymus independent antibodie?
what are the thymus dependent antibodies and what stimulates them to be made?
IgM - non specific
IgG - IFNgamma
IgE - IL-4
IgA - TGFbeta
in primary response what antigen is most common?
secondary?
IgM
IgG - faster stronger better longer higher affinity
