Lecture 10- T Cells and the Destruction of Cell Associated Invaders Flashcards
Which cells are most associated with cell-mediated immunity?
Cytotoxic T cells
How do cytotoxic T cells know which cells to destroy?
Infected cells express MHC I
What is endogenous antigen
Pathogenic particles produced within an infected host cell
Antigen bound to MHC I triggers what?
Cytotoxic T cells
What is on the surface of cytotoxic T cells?
CD8
TCR, CD3, integrins
What are integrins?
Surface molecules used to adhere to infected cells
What are the two main parts of integrin binding?
LFA-1 (on CTL) and ICAM1 (on infected cell)
Do B and Th cells have integrins?
No
Which cell activates CTL
Th1
Where do CTL reside?
Lymph nodes
Which two pathways do CTLs use to kill infected cell?
Perforin pathway
Fas pathway
What is released to kill infected cells at the LFA-1 junction in the perforin pathway?
perforin and granzymes
What is perforin
pore-forming molecule
What are granzymes?
Molecules that induce apoptosis once within a cell
What is the Fas pathway?
Fas-L ligand on CTL binds to Fas death receptor on target cell to trigger apoptosis
What receptor is used to trigger apoptosis in ANY unwanted cell?
Fas
What type of disease is a faulty Fas highly associated with?
Autoimmune
What cells can be cytotoxic?
CTL, Macrophages, and NKC
How do macrophages become cytotoxic?
Th1 cells activate them to destroy intracellular pathogens
What mediates cytotoxic macrophages?
PAMPs, IFN-g, IL-2 from Th1, and NK cells
What do cytotoxic NK cells target?
cells that do not express MHC I
Which cytotoxic cell plays the biggest role in fighting tumors?
NK cells
What does ADCC stand for
Antibody-dependent cell-mediated cytotoxicity
Do NK cells require activation to become cytotoxic?
No
Which two methods can NK cells use to kill cells?
ADCC (detects antibodies using Fc receptor) or perforins and granzymes
Which cytotoxic cells are MHC restricted
CTL
