RRC ID 72831
Author Sumitomo-Kondo M, Ukai Y, Iba Y, Ohshima N, Miura K, Takasaki A, Kurosawa Y, Kurosawa G.
Title Isolation of human monoclonal antibodies that bind to two different antigens and are encoded by germline VH and VL genes.
Journal Biochem Biophys Res Commun
Abstract This paper reports isolation of two monoclonal antibodies (mAbs) that bind to both a membrane protein and a cytoplasmic protein. Most Abs established as markers for autoimmune disease bind to cytoplasmic or nuclear substances. However, it remains unknown how these Abs are produced. On the other hand, there were examples where clones originally isolated as Abs that bind to membrane proteins also showed binding activity to cytoplasmic or nuclear substances. Based on these results, the following hypothesis has been proposed. The Abs that had been originally produced against a membrane protein showed cross-reactivity against cytoplasmic or nuclear substances. In the present study we reported isolation of Abs that bound to both a membrane protein, CADM1, and a cytoplasmic protein, α-actinin-4. The method adopted in the present study could be generally applicable to isolation of Abs showing such dual specificity. Firstly, we constructed a huge human Ab library using various organs including naïve B-cell-rich organs such as bone marrow and umbilical cords. Then, we developed a comprehensive screening method for isolation of Abs that bound to cell surface antigens. Through extensive screenings with many kinds of cell we newly obtained a library composed of around 4000 independent clones that bind to membrane proteins. We screened this library with α-actinin-4 and succeeded in isolating two Abs. They bound to α-actinin-4 and a membrane protein CADM1. Furthermore, they are encoded by naïve heavy and light chain variable genes (VH & VL). These results suggested that cross-reactive Abs to both a membrane protein and a cytoplasmic protein could be present in germline repertoire of Ab in humans. This methodology adopted in the present study could be applied to isolation of cross-reactive Abs possibly involved in autoimmune diseases.
Volume 503(2)
Pages 1141-1147
Published 2018-9-5
DOI 10.1016/j.bbrc.2018.06.132
PII S0006-291X(18)31445-1
PMID 29944883
MeSH Actinin / immunology* Amino Acid Sequence Antibodies, Monoclonal / chemistry Antibodies, Monoclonal / genetics Antibodies, Monoclonal / immunology* Cell Adhesion Molecule-1 / immunology* Cell Line Cross Reactions Hep G2 Cells Humans Immunoglobulin Variable Region / chemistry Immunoglobulin Variable Region / genetics Immunoglobulin Variable Region / immunology Immunoprecipitation
IF 2.985
Human and Animal Cells Hep G2