Production of murine collagen-induced arthritis using Klebsiella pneumoniae O3 lipopolysaccharide as a potent immunological adjuvant.

Collagen-induced arthritis (CIA) was produced in mice with non H-2q and H-2r haplotypes by repeated immunization of porcine type-II collagen (CII) together with Klebsiella O3 lipopolysaccharide (KO3 LPS) as an immunological adjuvant. Histological changes that appeared in joints of repeatedly immunized mice were characterized by destruction of normal joint structure, synovial hyperplasia with proliferation of synovial cells, and infiltration of inflammatory cells. No such lesions were produced in mice receiving repeated injections of CII alone or KO3 LPS alone. Development of the humoral antibody and the delayed-type hypersensitivity to CII was exclusively found in mice immunized with the mixture of CII and KO3 LPS. It was therefore suggested that arthritis lesions induced by repeated immunization with the mixture of CII and KO3 LPS might be caused by an autoimmune mechanism, and that the experimental model might be useful for characterization of human rheumatoid arthritis (RA).