Objectives and Vocabulary for Week Eight Flashcards
Nu/Nu mice
Nude Mice; lack a thymus; show deficiency in T Cell Development
SCID
Severe Combined Immuno-deficiency; caused by mutation in Rag1/2 genes; causes issues in recombination of receptors; notable loss of lymphocytes
Notch-1
Transcription Factor that is responsible for commitment to T cell lineage
X-Linked SCID
Mutation in gamma chain, causes inability of IL-7, IL-2, and IL-15 to be recognized by their receptors. Causes block in T cell and NK cell development, but normal B cell development.
Notch-1
Along with Gata-3 are the transcription factors important for HSC commitment to the T Cell lineage
Double Positive Cells
Cells are CD8+/CD4+; TCR a rearrangement, expression of TCRab heterodimer occur in DP stage.
When does the rearrangement of the alpha chain occur? What causes its induction?
rearrangement of the alpha chain occurs in the late Pre-T cell stage, due to 2nd wave of Rag1/2 expression.
Double Negative Cells
Most immature; no TCR, CD3, z chain, CD4 or CD8; considered to be a pro-T Cell stage.
Single Positive Cells
CD4+ or CD8+; undergo negative selection; arise post positive selection
CD44
Involved in leukocyte adhesion to endothelial cells and extracellular matrix
CD25
(IL-2Ra) Enables activated T cells to respond to growth promoting cytokine IL-2
CD40L
Post antigen recognition, 24-48 hours, T Cells up regulate CD40L , enables activated T cells to mediate their key effector functions, which are to help macrophages and B cells.
Pre-TCR
Rearranged TCR B chain, Pre-Ta, CD3, z proteins; only if B chain is rearranged correctly, gives survival signals.
Pre-Ta
invariant chain similar to light chain in B cell development. Important in the function of the Pre-TCR and proliferation of the Thymocyte.
