Abstract
IntroductionThe Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE). EBV nuclear antigen‐I (EBNA‐1) is the major nuclear protein of EBV. We previously generated an IgG monoclonal antibody (MAb) to EBNA‐1, 3D4, and demonstrated that it cross‐reacts with double stranded DNA (dsDNA) and binds the 148 amino acid viral binding site (VBS) in the carboxyl region of EBNA‐1. The aim of the present study was to characterize another antibody to EBNA‐1 that cross‐reacts with dsDNA, compare its immunoglobulin genes to 3D4, and finely map the epitope in EBNA‐1 that is recognized by these cross‐reactive antibodies.MethodsWe generated an IgM MAb to EBNA‐1, 16D2, from EBNA‐1 injected mice and demonstrated by ELISA that it cross‐reacts with dsDNA and binds the 148 amino acid VBS. We sequenced the variable heavy and light chain genes of 3D4 and 16D2 and compared V gene usage. To more finely map the epitope in EBNA‐1 recognized by these MAbs, we examined their binding by ELISA to 15 overlapping peptides spanning the 148 amino acid domain.ResultsSequence analysis revealed that 3D4 and 16D2 utilize different VH and VL genes but identical JH and Jk regions with minimal junctional diversity. This accounts for similarities in their CDR3 regions and may explain their similar dual binding specificity. Epitope mapping revealed 3D4 and 16D2 bind the same peptide in the VBS. Based on the crystal structure of EBNA‐1, we observed that this peptide resides at the base of an exposed proline rich loop in EBNA‐1.ConclusionWe have demonstrated that two MAbs that bind EBNA‐1 and cross‐react with dsDNA, recognize the same peptide in the VBS. This peptide may serve as a mimetope for dsDNA and may be of diagnostic and therapeutic value in SLE.
Highlights
The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE)
We previously demonstrated that some mice immunized with Epstein Barr virus nuclear antigen 1 (EBNA-1) developed antibodies to EBNA-1 that cross-reacted with double stranded DNA (dsDNA)
We characterized an IgM monoclonal antibody (MAb) to EBNA-1, designated 16D2, that was generated from somatic cell fusion following injection of a mouse with recombinant EBNA-1 protein lacking the glycine alanine repeat region, as previously described [25]
Summary
The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE). Methods: We generated an IgM MAb to EBNA-1, 16D2, from EBNA-1 injected mice and demonstrated by ELISA that it cross-reacts with dsDNA and binds the 148 amino acid VBS. Conclusion: We have demonstrated that two MAbs that bind EBNA-1 and crossreact with dsDNA, recognize the same peptide in the VBS This peptide may serve as a mimetope for dsDNA and may be of diagnostic and therapeutic value in SLE. Further evidence linking EBV to SLE is based on studies demonstrating that antibodies to the Epstein Barr virus nuclear antigen 1 (EBNA-1), the major nuclear protein in EBV which is expressed in all EBV infected cells, cross-react with the splicesomal ribonucleoproteins, Sm B/B0, Sm D, nRNPs, and Ro. Antibodies to Sm are observed in approximately 25% and antibodies to Ro in approximately 50% of lupus patients [2, 15]. Mice immunized with this EBNA-1 peptide, developed antibodies to Sm D as well as to the immunizing peptide
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
