T cell development

Question 1

where are projector cells differentiated into different types of T cells

Answer 1

thymus

Question 2

what are conventional T cells

Answer 2

CD4 and CD8

Question 3

what are unconventional T cells
-NKT cells
-MAIT cells
_γδ T cell
why not the same as conventional T cells

Answer 3

recognise pathogen products on non-classical MHC molecules or as free antigens.
-dont have the same specificty as only recognise certain antigens

Question 4

what is classed as αβ T cells

Answer 4

-CD4
-CD8
_NKT
-MAIT

Question 5

what are
1)NKT cells
2)MAIT cells
3) γδ T cells
-where are they found
-what do they express in terms of TCRα chain and TCRβ chains
-what one is the first T cell to leave the thymus prenatally and early following birth

Answer 5

1) found throughout the body
-express one partiular alpha chain and limited beta chain

2) found in mucousal sites
-express restricted alpha chain and limited beta chain

3) found in mucousal tissue in skin
-express limited TCR repertoire
-first to leave the thymus

Question 6

key events in T Cell development
first= commitment to T cell lineage of Double Negative cells

Answer 6

no CD4 or CD8 expression
-occurs in thymus

Question 7

second= generation of unqiue TCR molecules. generates double positive cells

Answer 7

single posiitve CD4 and CD8
-occurs in thymus

Question 8

third= generates single positive by positive selection

Answer 8

removes cells that cannot recognise self MHC.
single positive CD4 or CD8

Question 9

fourth= negative selection
-AIRE

Answer 9

removes cells that strongly recognise self peptides
-generates mature CD4 and CD8 T cells
AIRE= molecule that promotes expression for tissue specific antigens. coordinates this process

Question 10

how can apoptosis occur in positive and negative selection during recognition of peptide-MHC

Answer 10

positive- binding of TCR to self peptide thats too weak
negative- binding of TCR to self peptide MHC that’s too strong