M. Suzuki et al., Cloning and functional analysis of anti-double strand DNA IgG autoantibodies using the phage-display method, INT J MOL M, 3(4), 1999, pp. 385-390
To examine the relationship between pathophysiolo gical effects and molecul
ar features of anti-double-stranded (ds)DNA autoantibodies (Abs), we isolat
ed anti-dsDNA Ab fragments by using the phage-display method. Fd gamma and
light-chain DNA were PCR amplified from peripheral blood lymphocytes of a p
atient with systemic lupus erythematosus (SLE), complicated with lupus neph
ritis. They were then inserted into a phagemid vector, pComb3-H. We generat
ed eight Fab fragments that specifically bound to solid-phase DNA. The Fab
clones stained positively using Crithidia luciliae, indicating that they we
re anti-dsDNA antibodies. Nucleotide sequences of VH of Fab clones were ver
y similar and appeared to be derived from VH26 germline gene. Differences i
n the activities of anti-dsDNA Ab of the Fab clones may be ascribed to the
diversity of VL. Fab fragments with anti-dsDNA Ab activities exhibited a po
sitive charge on isoelectric focusing, consistent with pathogenic features.
Our results indicate that anti-dsDNA Ab Fab fragments obtained by the phag
e-display method in the present study may possess molecular and functional
characteristics of pathogenic anti-dsDNA autoAbs in SLE.