Literature Survey
Abstract
Computer model of somatic mutation and antibody repertoire Two types of antibody diversity repertoires are usually recognized: the potential and the available. The potential is that encoded in the germline, whereas the available is the antibody specificities expressed at one point in time as surface immunoglobulins on existing immunocompetent B cells. If somatic mutation is also considered, a larger repertoire known as the complete repertoire can be recognized. This is important as somatic mutation has been implicated as a major factor in the maturation of antibody affinity. This is mediated by hypermutation in the gene segments that code for the antigen binding site of the antibody. This process has been investigated by a computer model. The model, which is written in VAX FORTRAN/ULTRIX and run on a DEC VAXStation 3500, is based on a large complete repertoire of 65 536 antibody specificities, which equates to â6000 germline specificities. The size of the available repertoire was obtained by assuming that each clone in the potential repertoire is synthesized every 50 cell cycles on average. Thus an average of 120 clones are synthesized each cycle. Additional assumptions about the cell lifespan and the number of cells/clone leads to an estimate