Y. Hirabayashi et al., HUMAN B-CELL CLONES EXPRESSING LUPUS NEPHRITIS-ASSOCIATED ANTI-DNA IDIOTYPES ARE PREFERENTIALLY EXPANDED WITHOUT SOMATIC MUTATION, Scandinavian journal of immunology, 37(5), 1993, pp. 533-540
Human monoclonal anti-single/double-stranded (ss/ds) DNA antibodies (N
E-1 and NE- 1 3) expressed cross-reactive idiotypes (Id), NE-1 Id, whi
ch have been detected on the lupus glomeruli-deposited anti-DNA antibo
dies. The nucleotide sequences of the variable regions of NE-1 and NE-
13 clones were analogous except for one nucleotide difference in the V
(k) region. The V(H) and V(k) gene segments of NE-13 clone were identi
cal with germline genes VH4.21 and Vb (or Vb'), respectively. CDR3s of
NE-1 and NE-13 heavy chains were arginine rich and CDR1s contained an
amino acid stretch, SGYY, the inverted sequence of YYGS, which was sh
ared among CDR3s of several anti-DNA antibodies. Clonal frequency anal
ysis using a limiting dilution method revealed that NE-1 Id-positive c
lones at precursor cell level increased in lupus patients. These findi
ngs suggest that some IgM anti-DNA clones which express NE-1 Id associ
ated with lupus nephritis use germline genes without mutation and they
may be preferentially expanded at the precursor cell levels as well a
s at the mature cell level.