Rheumatoid factor in idiotypic regulation of autoimmunity. (26th March 2014)

• Record Type: Journal Article
• Authors: Beduleva, Liubov; Menshikov, Igor; Stolyarova, Elena; Fomina, Kseniya; Lobanova, Olga; Ivanov, Pavel; Terentiev, Alexey
• Is Part Of: International journal of rheumatic diseases. Volume 18:Number 4(2015)
• Page Start: 408
• Page End: 420
• Publication Date: 2014-03-26
• Subjects: Rheumatology -- Periodicals; Rheumatology -- Asia -- Periodicals; Rheumatology -- Pacific Area -- Periodicals; Rheumatic Diseases -- Periodicals; Connective Tissue Diseases -- Periodicals; Immune System Diseases -- Periodicals; 616.723
• DOI: 10.1111/1756-185X.12335
• Languages: English
• ISSNs: 1756-1841

Abstract

<abstract abstract-type="main" id="apl12335-abs-0001"> <title>Abstract</title> <sec id="apl12335-sec-0001" sec-type="section"> <title>Aim</title> <p>Rheumatoid factor (RF) is known to be heterogeneous, and RFs detected by various methods exhibit different characteristics. In addition to interacting with the Fc region of immunoglobulin G (IgG), certain RFs are able to recognize idiotypes of antibodies. Given the important role of idiotypic interactions in regulating autoimmunity, we hypothesize that RF is involved in regulation of lymphocyte activity against autoimmune disease‐inducing antigens via idiotype–anti‐idiotype interactions with these lymphocytes.</p> </sec> <sec id="apl12335-sec-0002" sec-type="section"> <title>Method</title> <p>RF level and the existence of idiotype–anti‐idiotype interactions between RF and antibodies to autoimmunity‐inducing antigens were studied in rats resistant and sensitive to collagen‐induced arthritis, encephalomyelitis and atherosclerosis. RF was assayed by agglutination of tanned IgG‐loaded erythrocytes.</p> </sec> <sec id="apl12335-sec-0003" sec-type="section"> <title>Results</title> <p>Rat resistance to autoimmune disease is associated with high RF production during the initiation of the immune response, and a low RF level during this period may be a preclinical marker of experimental autoimmune disease manifestation. RF‐containing sera compete with an antigen if the RF‐containing sera were obtained from rats immunized with that antigen, and they non‐specifically inhibit binding of different antigen‐antibody pairs. This suggests that RFs are anti‐idiotypic antibodies that carry two kinds of paratopes: a particular paratope that recognizes the antigen‐binding sites of antibodies, and a shared paratope that serves to recognize the recurrent idiotype on antibodies. Antigenic epitopes for the shared RF paratope can be created in the hinge region of Fc fragments of homologous IgG.</p> </sec> <sec id="apl12335-sec-0004" sec-type="section"> <title>Conclusion</title> <p>RF detected by agglutination of tanned IgG‐loaded erythrocytes is involved in negative idiotypic regulation of lymphocytes specific to autoimmunity‐inducing antigens.</p> </sec> </abstract>