T-cell development Flashcards
TCR has a _____ and a _____ region
TCR has a variable and a constant region
Most common TCRs are composed of an ____ and _____ chain. Less common ones have ____ and ____ chains.
Most common TCRs are composed of an alpha and beta chain. Less common ones have gamma and delta chains.
Unlike Ig’s, in TCRs:
1) Tere is no soluble form of a TCR
2) There is no class switch recombination (CSR) or Somatic Hypermutation
TCR transduce signals through ______
CD3
Why is CD3 necessary in TCRs?
TCR recognizes antigen but does not have intracellular tails. So CD3 sends transduce signal.
T cells respond to antigen from _____ a host cell
T cells respond to antigen from inside a host cell
Pathogen and protein antigens get into host cells by: ____, or _____ or ______
Pathogen and protein antigens get into host cells by: Infection, or endocytosis or phagocytosis
TCR must interact with ____ + ____ in order to be activated
TCR must interact with MHC + Peptide in order to be activates
MHC class I is expressed on _____ cells and interact with CD_.
MHC class I is expressed on nucleated cells and interact with CD8.
MHC class II is expressed on _____ cells (3 types): _____cells, ____cells, and ______. These interact with CD__.
MHC class II is expressed on antigen-presenting cells (3 types): dendrite cells, B cells, and macrophages.
CD8 and CD4 are co-receptors that 1)______ and 2) _____.
CD8 and CD4 are co-receptors that 1) stabilize binding and 2) enhance signaling
Activated CD4+ T cells produce ______, which are proteins that _______
Activated CD4+ T cells produce cytokines, which are proteins that signal other cells
Activated CD8+ T cells become _______. Which _____ other cells
Activated CD8+ T cells become cytotoxic T lymphocytes (CTL). Which kill other cells
The 2 co-receptors are _____ and ____
CD4 and CD8
The ______ is the primary lymphoid organ for T cell development
The thymus is the primary lymphoid organ for T cell development
Precursor of T-cell migrates from _____ to ______
Precursor of T-cell migrates from bone marrow to thymus
If the thymus is absent ______ will be absent
If the thymus is absent mature T cells will be absent
Syndrome due to little or no thymus and results in lack of mature T cells and recurrent infections. It affects heart and parathyroids and patients have characteristic facial features.
DiGeorge Syndrome.
______ enters the thymus from the bone marrow.
Lymphoid progenitor
______ (____recombination) rearrange and form a _____
TCR genes (V(D)J recombination) rearrange and form a Double negative thymocyte
Double negative Thymocyte
No CD4 or CD8
After TCR gene rearrangement a _____ thymocyte is formed
After TCR gene rearrangement a double positive thymocyte is formed
Double positive thymocyte
Has CD4+ and CD8+
Double positive thymocyte
Has CD4+ and CD8+
In the cortex of the thymus, the double positive thymocyte undergoes _____
positive selection
Positive selection
Select for T-cels that bind to patient’s own MHCs
After positive selection, _____ takes place in the _____
After positive selection, negative takes place in the thymus medulla
Negative selection
Deletion of self-reactive CD4+ and CD8+ cells
