Development of T and B Lymphocytes Flashcards
What is the process by lymphocytes are created called?
Lymphopoiesis
What is a key defining feature of lymphocytes?
Presence of an acceptable antigen receptor
What is the first part of the receptor expressed on a pre-B cell?
Heavy chain
What is the first par of the receptor expressed on a pre-T cell?
Beta-chain
What occurs if an immature B or T cell expresses strong recognition of an antigen?
They are killed
Which region on T and B cells are encoded by a combo of gene segments?
Variable Heavy Light
Variable alpha and beta
How can unlimited variable receptors for T and B cells beta and heavy chains be possible?
V D J gene segments are rearranged in the receptors genome
How are multiple alpha and light chains encoded?
V and J gene segments rearrange and come together
What codes for the C region in both T and B cells?
C region in the genome
What do recombination signal sequences (RSS) do?
They are directly adjacent to the coding sequence of V, D, and J gene segments
What does V(D)J recombinase do?
Recognizes RSS and mediates recombination process
What are RAG-1 and RAG-2?
Recombinase-activating gene
What do RAG-1 and RAG-2 do?
Encode for recombinase activating needed for V(D)J recombinase to work
What is combinatorial diversity?
Movement of the V D J segments adds diversity in receptor chains
What is junctional diversity?
Nucleotides are added or moved at the VD or VDJ segments for added diversity
What is terminal deoxynucleotidyl transferase (TdT) do?
Adds nucleotides at junctions
