Immunology Iv

Front 1

What do the V, D, and J units of the the antibody gene stand for?

Back 1

Variable, diversity, and joining (respectively)

Front 2

Which gene loci correspond to heavy and which to light chain DNA?

Back 2

Heavy: All of the VDJ variations + C regions mu, delta, gamma (1-4), alpha, epsilon

Light: VJC for lambda in sets of V-JC
VJC for kappa in sets of V, J, C

Front 3

Where and when does V(D)J recombination occur?

Back 3

In the pro-B cell, prior to transcription, in the bone marrow

Front 4

What is an RSS? What is its structure and function?

Back 4

A rearrangement signal sequence is a conserved sequence of DNA that flanks each segment of gene rearrangement DNA (each individual V, D, and J segment) consisting of a heptamer followed by a 12- or 23-mer and a nonamer. The 12/23-mer spacer serves to ensure proper rearrangement (s.t. only segments with unlike spacers may be matched--i.e. heavy chain V will not match to heavy chain J, but only heavy chain D).

Front 5

What is the distinction between 1- and 2-turn RSS?

Back 5

1- turn = 12 nt spacer RSS faces nonamer toward the 5' (V) end

2-turn = 23 nt spacer RSS faces nonamer toward the 3' (J) end

Front 6

What are P and N regions, how are they related to B cell development?

Back 6

P regions are generated when, after splicing DNA for VDJ rearrangement, hairpin regions occur at the ends of strands. Resolution of the hairpin results in the P region.

N nucleotides are added by enzyme TdT as complement to the P region template (because it cannot be assumed that precisely the complement P region exists on the complementary strand.