Flashcards in T cells 2 Part 1 Deck (66)
What do Tk cells do?
kill other cells
What do Th cells do?
help other cells
Where are T cells made?
Where do T cells mature?
in the thymus (T for thymus)
T/F: T cells circulate in the blood and lymph.
T/F: T cells cannot enter tissue
false; they can
What are the antibody like receptors on the surface of T cells called?
T cell receptors (TCRs)
What do TCRs specialize in?
recognizing protein antigens presented by MHCs (this means the antigen is a peptide)
T/F: there are about 300 million T cells in the body on average.
False; 300 billion, with a B.
What are killer T cells also called?
cytotoxic T cells (CTLs)
How are killer T cells activated?
by MHC I being presented on cells
T/F: most cells in the body can present antigens to CTLs via MHC class II molescules.
False; should say MHC I molecules
What connects to the target cell and triggers it to commit suicide killing the cell and the virus inside it?
Killer T cells/CTLs
What activates Helper T cells (Th)?
MHC II on Antigen Presenting Cells (APCs)
What is secreted by Helper T cells?
cytokines IL-2 and IFN-y (interferon gamma)
What kind of cells keep the immune system from overreacting?
Regulatory T cells
T/F: regulatory T cells are probably the one part of the immune system that we know the most about.
False; much is still unknown about regulatory T cells
T/F helper T cells do not require activation to perform their function.
False; both helper and killer T cells require activation
What kind of cells help Helper T cells?
APCs (activated dendritic macrophage and B cells)
What must a TCR recognize in order to be activated?
What must the Co-receptor recognize in order for activation to occur?
MHC (either I or II)
What happens during Co-stimulation?
other receptors recognize other molecules (besides for cognate antigens and MHCs)
T/F: more is known about Helper T cell activation than Killer T cell activation.
True (think alphabetical order)
What happens to T cells that see "self" being presented by other cells?
These die. T cells that would kill self need to go away.
How are T cells anergized?
When T cells recognize self antigen, but do not get co-stimulated they will be rendered inactive or anergized.
What happens to a T cell that sees non-self and gets co-stimulated?
What happens when a TCR recognizes MHC plus self peptides?
T cell commits suicide (apoptosis)
What happens when TCR recognizes cognate antigen on MHC with no co-stimulation?
T cell is anergized (inactivated)
What happens when TCR recognizes cognate antigen on MHC plus co-stimulation?
T cell is activated