Толерантность, вызванная циклоспорином а в модели коллаген-индуцированного артрита крыс, опосредована ревматоидным фактором

Cyclosporin A is an immunosupressor widely used in clinical practice. The peculiarity of its action is the formation of a transplantation tolerance. The ability of cyclosporin A to induce the antigen-specific tolerance means that the mechanism of cyclosporin A action involves the regulatory mechanisms which maintain the state of immune suppression after withdrawal of cyclosporin A. The important role of rheumatoid factor in the suppression of immune response allows to assume that rheumatoid factor can be involved into the process of reaching tolerance caused by cyclosporin A. It is the purpose of the present paper to investigate the role of rheumatoid factor in cyclosporin A induced suppression in rat collagen-induced arthritis model. We have revealed that a five-day course of cyclosporine A after immunization with bovine collagen (the day of the immunization included) induces tolerance to bovine collagen. Rheumatoid factor was measured by means of two different test systems allowing to define two populations of rheumatoid factor. Said populations differed in specificity. One of the populations was defined in the test system where IgG-homologous-coated erythrocytes acted as the antigen. The other population was defined in the system where rabbit IgG was used as the antigen. It was observed that a five-day course of cyclosporin A induced in rats after immunization with bovine collagen suppresses the production of collagen-directed antibodies but causes the intensive production of both populations of rheumatoid factor with the peak intensity on the seventh and on the fourteenth days after immunization. The animals which underwent a five-day course of cyclosporin A after bovine collagen immunization do not respond to the repeated administration of bovine collagen, which indicated to the development of tolerance to bovine collagen. Tolerance to bovine collagen is associated with induction of high level of rheumatoid factor, which regulates the activity of anti-bovine collagen lymphocytes by idiotype-anti-idiotype interactions.