Numerical modelling of the V-J combinations of the T cell receptor TRA/TRD locus.
T-Cell antigen Receptor (TR) repertoire is generated through rearrangements of V and J genes encoding alpha and beta chains. The quantification and frequency for every V-J combination during ontogeny and development of the immune system remain to be precisely established. We have addressed this issue by building a model able to account for Valpha-Jalpha gene rearrangements during thymus development of mice. So we developed a numerical model on the whole TRA/TRD locus, based on experimental data, to estimate how Valpha and Jalpha genes become accessible to rearrangements. The progressive opening of the locus to V-J gene recombinations is modeled through windows of accessibility of different sizes and with different speeds of progression. Furthermore, the possibility of successive secondary V-J rearrangements was included in the modelling. The model points out some unbalanced V-J associations resulting from a preferential access to gene rearrangements and from a non-uniform partition of the accessibility of the J genes, depending on their location in the locus. The model shows that 3 to 4 successive rearrangements are sufficient to explain the use of all the V and J genes of the locus. Finally, the model provides information on both the kinetics of rearrangements and frequencies of each V-J associations. The model accounts for the essential features of the observed rearrangements on the TRA/TRD locus and may provide a reference for the repertoire of the V-J combinatorial diversity.
Thuderoz
Florence
F
CNRS, Laboratoire TIMC-IMAG, UMR 5525, Grenoble, France.
Simonet
Maria-Ana
MA
Hansen
Olivier
O
Pasqual
Nicolas
N
Dariz
Aurélie
A
Baum
Thierry Pascal
TP
Hierle
Vivien
V
Demongeot
Jacques
J
Marche
Patrice Noël
PN
Jouvin-Marche
Evelyne
E
D000818:Animals; D003198:Computer Simulation; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor / Q000235:genetics*; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor / Q000235:genetics; D019673:Genes, T-Cell Receptor alpha; D019676:Genes, T-Cell Receptor delta; D051379:Mice; D008807:Mice, Inbred BALB C; D018448:Models, Immunological; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D015203:Reproducibility of Results
D016693:Receptors, Antigen, T-Cell, alpha-beta