IGHV3-21 stereotyped subset-2 chronic lymphocytic leukemia cells make autoantibodies that bind to an 11.5kDa gastric mucosal antigen
(English)Manuscript (preprint) (Other academic)
Background: The immunoglobulin heavy chain variable region (IGHV) gene mutational status is an important prognostic factor in chronic lymphocytic leukemia (CLL). Patients with mutated IGHV genes show significantly longer survival than unmutated cases. CLL patients with mutated IGHV3-21 genes, however, have a shorter survival compared to other mutated CLL cases. Recently, we showed that CLL cells react with oxidized epitopes exposed on apoptotic cells and bacteria. The gastric mucosal reactivity was of special interest to further characterize in detail.
Methods: We collected corpus biopsies from seven Helicobacter pylori (H.p.)+ study subjects withnon-atrophic gastritis, six subjects with H.p.- atrophic gastritis, eight subjects with H.p.+ atrophicgastric and from eight controls without gastritis. The binding pattern of CLL subset-2 IGHV3-21antibodies was analyzed by immunohistochemistry and the antigen was biochemically purified byaffinity chromatography.
Results: The subset-2 IGHV3-21 Abs bound to mucosal glands in 18 of 29 cases regardless of H.p.status or diagnosis. It also showed staining of connective tissue in all of the biopsies. The antigen waspurified and a protein of 11.5 kDa MW was isolated.
Conclusion: The results from this study indicate that IGHV3-21 subset-2 CLL Abs bind an 11.5kDaprotein present in gastric mucosal glands or connective tissue. This autoantigen has no associationwith H.p. since it is present in normal, non-atrophic H.p.+ and atrophic H.p.+/H.p.- gastric mucosafrom corpus. The exact nature of the 11.5 kDa protein is currently under detailed structure massspectrometry analysis in order to reveal whether bacterial mimicry is the mechanism behind theinduction of this particular autoantibody.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-53279OAI: oai:DiVA.org:liu-53279DiVA: diva2:288128