SIMILAR CHARACTERISTICS OF THE CDR3 OF V(H)1-69 DP-10 REARRANGEMENTS IN NORMAL HUMAN PERIPHERAL-BLOOD AND CHRONIC LYMPHOCYTIC-LEUKEMIA B-CELLS/

The variable heavy chain (V-H) gene segment V(H)1-69/DP-10 has been sh own to be over-represented in B-cell chronic lymphocytic leukaemia (CL L). Because of certain similar characteristics of their complementarit y determining region 3 (CDR3), including preferential utilization of I (H)6 elements and an extended length, it has been suggested that antig enic stimulation might be involved in leukaemogenesis. Utilizing singl e-cell PCR to amplify and sequence genomic DNA from individual normal human peripheral blood B cells, we hare obtained 7/471 productively an d 1/69 nonproductively rearranged V-H genes that used V(H)1-69/DP-10, All productive rearrangements were unmutated, used J(H)6 and had an av erage CDR3 length similar to that previously found in V(H)1-69/DP-10-e xpressing CLL cells, These results suggest that CLL may arise from B c ells commonly found in the peripheral B-cell repertoire and do not rep resent expansion of a unique subset of specific antigen-reactive B cel ls.