V gene sequences of human anti-ssDNA antibodies secreted by lupus-derived CD5-negative B cell hybridomas.
V gene sequences encoding two lupus-derived human monoclonal IgMk anti-ssDNA antibodies (2F7 and 1A6) and CD5 mRNA expression by the corresponding hybridomas were investigated. Both antibodies displayed V gene sequences nearly in germline configuration compared with their putative germline counterparts. It appeared that 2F7 used hv3019b9/HUD-3/JH6 and 12La/Jk2, while 1A6 utilized HHG19/D31-HUD-3/JH2 and Humkv328h5/Jk1. Assessment of R/S mutation ratios suggested that 2F7 and 1A6 have not undergone the antigen-driven somatic mutation. The HCDR3 featuring arginine appeared to be important in determining the anti-ssDNA specificity. CD5 mRNA was negative in both hybridomas. Since 2F7 was previously shown to be monospecific and of high affinity, these results provide the molecular basis of such unique immunochemical characteristics of the IgM anti-ssDNA antibody. Germline V genes and N sequences may be selected to confer such anti-ssDNA specificity during V gene rearrangement, which might involve CD5-negative B cells.
Mitamura
K
K
Immunology Research Laboratory, St. Luke's Hospital, University of Missouri-Kansas City 64111, USA.
Suenaga
R
R
Wilson
K B
KB
Abdou
N I
NI
D000595:Amino Acid Sequence; D000974:Antibodies, Antinuclear / Q000096:biosynthesis* / Q000235:genetics; D000911:Antibodies, Monoclonal / Q000737:chemistry; D001402:B-Lymphocytes / Q000145:classification / Q000378:metabolism*; D001483:Base Sequence; D018956:CD5 Antigens / Q000235:genetics; D003001:Cloning, Molecular; D004277:DNA, Single-Stranded / Q000276:immunology*; D005803:Genes, Immunoglobulin / Q000276:immunology*; D006801:Humans; D006825:Hybridomas / Q000145:classification; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007144:Immunoglobulin J-Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics; D016130:Immunophenotyping; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D018956:CD5 Antigens; D004277:DNA, Single-Stranded; D007143:Immunoglobulin Heavy Chains; D007144:Immunoglobulin J-Chains; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D012333:RNA, Messenger