Flashcards in Objectives and Vocabulary for Week Eight Deck (14):
Nude Mice; lack a thymus; show deficiency in T Cell Development
Severe Combined Immuno-deficiency; caused by mutation in Rag1/2 genes; causes issues in recombination of receptors; notable loss of lymphocytes
Transcription Factor that is responsible for commitment to T cell lineage
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.
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
Involved in leukocyte adhesion to endothelial cells and extracellular matrix
(IL-2Ra) Enables activated T cells to respond to growth promoting cytokine IL-2
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.
Rearranged TCR B chain, Pre-Ta, CD3, z proteins; only if B chain is rearranged correctly, gives survival signals.