Models for antigen receptor gene rearrangement: CDR3 length

摘要: Despite the various processing steps involved in V(D)J recombination, which could potentially introduce many biases length distribution of complementarity determining region 3 (CDR3) segments, observed CDR3 distributions for complete repertoires are very close to a normal-like distribution. This raises question whether this is simply result random included process gene rearrangement, or has been optimized during evolution. We have addressed issue by constructing simulation takes into account DNA modification process, namely hairpin opening, nucleotide additions, and deletions. found that near-Gaussian- shape can only be obtained under relatively narrow set parameter values, thus our model suggests specific govern rearrangement process. In both B-cell receptor (BCR) heavy chain T-cell beta chain, we Gaussian using identical parameters, despite difference number lengths D segments. Hence results suggest these parameters most likely reflect optimal conditions occurs. subsequently used insights gained study estimate probability occurrence two exactly BCRs over course human lifetime. Whereas rearrangements highly unlikely occur within one lifetime, light not negligible, hence alone cannot serve as an indicator clonality.