The Anti-Self B Cell Repertoire

摘要: A notable feature of B cells that has been observed recently in several laboratories is a relatively small group VH segments predominates the expressed gene repertoire normal humans. The results number different experiments suggest phenomenon restriction due to clonal selection at level both mature and immature cells. For instance, examining sequences over-represented genes we found examples somatic mutations were typical an antigen-driven immune response, which manifestations cell clones (Huang, et al., 1992). But also cases had germline sequences. Each these unmutated was linked clonally unique (D-JH) CDR3 (Stewart, These latter findings process positive heavy chain do not mutate their genes. related have led us others propose occurs only but pre-B (Schwartz, 1993; Nishimoto, 1991; Decker, 1991). We differs from two ways: (a) lack mechanism for V mutation; (b) positively selected differentiation advantage, whereas gain proliferative advantage.