T Helper and Gamma Delta T cells, Th cell and B cell interaction Flashcards
What are the different types of lymphocytes?
B cells, gamma delta t cells, CD4 T-helper cells, CD8 cytotoxic T-cells, and CDTfh cells
How do B cells recognize antigen?
on intact, unprocessed molecules
How do gamma delta t cells recognize antigen?
on intact, unprocessed cell surface molecules
How do CD4 T helper cells recognize antigens?
exogenous peptides, processed and presented on MHC II molecules
How do CD4 T regulator cells recognize antigens?
self peptides on MHC II
How do CD8 cytotoxic cells recognize antigen?
endogenous peptides processed and presented on MHC I
What is the signature cytokine of TH1?
interferon gamma
What are the functions of TH1?
secrete cytokines to activate macrophages, neutrophils, NK cells, and CTL cells to be better killers and signal B cells to make opsonizing and complement fixing antibodies (IgG)
What are the signature cytokines of TH2?
IL3, IL4, and IL5
What are the functions of TH2?
activate mast cells and eosinophils and activate B cells to make IgE
What are the signature cytokines of TH17?
IL17 A
What is the function of TH17?
attract and activate neutrophils and monocytes
What are the signature cytokines of T regulatory cells?
TGF beta
What is the function of T regulatory cells?
suppress T cell response
What are the signature cytokines of Tf?
IL21
What is an example of an extracellular pathogen?
Staphylococcus or tetanus toxin
How is the antigen processed, to what T cell is it presented to, what s the effector response, and what is the outcome of the alpha beta T cell response to an extracellular pathogen?
processed on MHC II, presented to a T helper cell, effector response is by TH1 and TH17, and the outcome is the production of IgG and attraction of neutrophils
What is an example of an intravesicular pathogen?
mycobacteria bovis
How is the antigen processed, to what T cell is it presented to, what s the effector response, and what is the outcome of the alpha beta T cell response to an intravesiuclar pathogen?
processed on MHC II, presented to a T helper cell, effector response is by TH1, and the outcome is interferon gamma’s activation of macrophages to become more potent killers
What is an example of a helminthic pathogen?
roundworms
How is the antigen processed, to what T cell is it presented to, what s the effector response, and what is the outcome of the alpha beta T cell response to an helminthic parasite?
processed on MHC II, presented to a T helper cell, effector response is by TH2, and the outcome is the production of IgE leading to mast cell degeneration and the binding of eosinophils
What is an example of a cytosilic pathogen?
a virus
How is the antigen processed, to what T cell is it presented to, what s the effector response, and what is the outcome of the alpha beta T cell response to an cytosolic pathogen?
processed on MHC I and II, presented to a T helper cell and cytotoxic T cell, effector response is by CTL and TH1, and the outcome is the killing of the cell via apoptosis and ADCC
Where are gamma delta T cells located?
on mucosal surfaces
What type of immunity are gamma delta T cells involved with?
they seem to be in between innate and adaptive immunity
What is the function of gamma delta T cells?
they can secrete cytokines or cytotoxic T cells
How can an immune response to one type of pathogen inhibit the response to another type of pathogen (use example of TH1 response currently going on)?
If there is a TH1 response going on, IFN will inhibit TH2
How can an immune response to one type of pathogen inhibit the response to another type of pathogen (use example of TH2 response currently going on)?
if there is a TH2 response going on, IL4 will inhibit TH1 from responding
What can you do to get T cell help to B cells when B cells are responding to a polysaccharide antigen?
if you covalently bind the polysaccharide to a protein, the B cell will then ingest the antigen, process and present it on the Th cell which will result in activation, the b cells will proliferate and differentiate into plasma cells to produce antibodies and opsonize polysaccharide antigen on the surface of the bacterium
What are the major signals required to get T helper cell activation?
TCR + CD4 needs to bind to MHC II and peptide, co-stimulatory molecules, and cytokines
What determines the subtype of T helper cell that will predominate in the response?
the co-stimulatory molecules and cytokines tell the T helper cell what to predominate
What pathway do killed vaccines follow?
the exogenous pathway
Briefly explain how the exogenous pathway works.
the vaccine is phagocytized, broken up into peptides in a vesicle, bound to a MHC II molecule, and then presented to a CD4 cell
What pathway do live vaccines follow?
They can follow both exogenous and endogenous (primarily endogenous)
Briefly explain how the endogenous pathway works.
The foreign molecule is tagged with ubiquitin, processed by a proteosome, moved to the MHC I pathway and presented to the CD8 cell
