Base-specific binding of adenosine antibodies to double-stranded DNA

Impact of anti-peroxynitrite-damaged-thymidine-monophosphate antibodies on disease activity in patients with systemic lupus erythematosus

Present study probes the role of peroxynitrite (ONOO(-))-modified thymidine-5'-monophosphate (TMP) in SLE patients with different disease activity scores according to the SLE Disease Activity Index (SLEDAI). Serum analysis showed significant increased number of subjects positive for anti-ONOO(-)-TMP-protein antibodies in SLE patients with different SLEDAI scores. Interestingly, the levels of these antibodies were significantly higher among SLE patients, whose SLEDAI scores were ≥20. In addition, a significant correlation was observed between the levels of anti-ONOO(-)-TMP-protein antibodies and the SLEDAI score (r = 0.595, p < 0.0001). In short, this study shows a positive association between anti-ONOO(-)-TMP-protein antibodies and SLEDAI. The stronger response observed in patients with higher SLEDAI scores suggests that anti-ONOO(-)-TMP-protein antibodies may be useful in evaluating the progression of SLE and in elucidating the mechanisms of disease pathogenesis.

Preferential recognition of peroxynitrite damaged thymidine-monophosphate by anti-DNA autoantibodies in systemic lupus erythematosus

This study was undertaken to investigate the role of peroxynitrite (ONOO(-)) modified thymine-5'-monophosphate (TMP) in the generation of anti-DNA autoantibodies in patients with systemic lupus erythematosus (SLE). TMP was exposed to ONOO(-) in vitro and challenged in vivo. TMP and ONOO(-)-modified-TMP were found to be nonimmunogenic in rabbits. TMP-linked-BSA and ONOO(-)-modified-TMP-BSA induced high titer antibodies. Induced antibodies against ONOO(-)-TMP-BSA show crossreactions with nucleic acids conformers. A high degree of specific binding by SLE autoantibodies with ONOO(-)-TMP-BSA was observed. Our novel results provide an important insight into the immunological basis of anti-DNA autoantibodies generation in SLE.

Antigen binding characteristics of antibodies against hydroxyl radical modified thymidine monophosphate

Reactive oxygen species (ROS) are formed in living organisms during normal metabolic reactions as well as under different environmental stresses. In this study, thymidine monophosphate (TMP) was exposed to hydroxyl radical (OH) and challenged in rabbits. TMP and OH-modified TMP were found to be nonimmunogenic. The TMP was linked to bovine serum albumin (BSA) by carbodiimide reaction, and then modified with the OH. The neoantigens, TMP-BSA, and ROS-TMP-BSA conjugates induced highly specific antibodies against immunogens. Induced antibodies exhibited appreciable cross-reactivity with various polynucleotides and nucleic acids. In this respect, the induced antibodies resembled the diverse antigen-binding characteristics of naturally occurring systemic lupus erythematosus (SLE) anti-DNA autoantibodies.