L-35 Flashcards
What are the state of the TCR genes in immature cells in the bone marrow?
Germline
What occurs in the thymus to T cells?
They go through TCR gene rearrangement to produce mature naive T cells expressing unique TCRs
What occurs during thymus gene rearrangement?
- immature T cells called thymocytes rearrange the variable parts of their TCR genes in the thymus
- this rearrangement process is essentially random which ensures that individual T cells are unique in terms of their TCR
- this creates diversity in the T cell repertoire
What are the two states T cells can be in?
- naive
- effector
What is a naive T cell
A T cell that has not been activated by MHC/peptides
What is a thymocyte?
An immature T cell
What is the role of a CD4 T helper cell? (3)
- recognises MHC-II/peptide
- helps CD8 T cell become cytotoxic
- helps B cell make antibody
What is the role of a CD8 T cell? (2)
- recognises MHC-I/peptide
- develops into cytotoxic T lymphocyte (CTL)
How do CD4 helper cells help CD8 T cells become cytotoxic?
They release cytokines
What does CTL stand for?
Cytotoxic T lymphocyte
What do CTL’s do?
Kill virally infected cells by inducing apoptosis
What is apoptosis?
Programmed cell death
What are the two results from T cell activation?
- memory T cells
- effector cells
What are the benefits of having memory memory T cells in the body
- can stay in body for long periods of time
- become effector cells much faster than naive T cells
What cytokine does CD4 helper cells release when stimulating the activation of CD8 T cells to CTL and B cells.
Interleukins
