Immune 6 Flashcards
What are T cells?
- lymphocytes that arise in the bone marrow and fully develop in thymus
- T cells express T cell receptor (TCR) with co-receptors (either CD4 or CD8)
- recognise MHC / peptide complexes
T cell life
Production of T cells precursors occurs in bone marrow, these are then transported into the blood and into the thymus where T cell deveopment and TCR gene rearrangement occurs
Where do T cells develop
Thymus gene rearrangement
- immature T cells (thymocytes) rearrange the ‘viable’ parts of their TCR genes in the thymus
- the rearrangement process is essentially random
- this ensures that individual T cells are unique in terms of their TCR
- creates ‘diversity’ in T cell repertoire
How T cells express a unique T cell receptor
How T cells ‘doc’ onto dendritic cells
T cells express a T cell receptor (TCR) that recognises peptide + MHC
CD4 and CD8 ‘co-receptors’ on T cells
CD4 and D8 expression on T cells - what do they do?
CD4 and CD8 molecules assist with the docking of the TCR onto MHC-11 or MHC-1 respectively
“Naive”
- T cells that have not been activated by MHC / peptide
Effector T cells
- activated T cells
What does the CD4 T helper cell do?
- recognises MHC-11 / peptide
- helps CD8 T cell become cytotoxic
- helps B cell make antibody
What does the CD8 T cell do?
- recognises MHC-1 / peptide
- develops into ‘cytotoxic T lymphocyte’ (CTL) - ‘cytotoxic T cell’
______ produced by _______ _ ____ help CD8 T cells become ____
Cytotoxic T lymphocytes
- they release granules that are very specific and when receives signals will be secreted and kill virus meaning the virus can no longer hijack host cell and the cell is destroyed
TALKING
Thingy
