International Immunology Advance Access originally published online on March 2, 2009
International Immunology 2009 21(5):511-522; doi:10.1093/intimm/dxp018
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Th1/Th17 polarization and acquisition of an arthritogenic phenotype in arthritis-susceptible BALB/c, but not in MHC-matched, arthritis-resistant DBA/2 mice
1 Section of Molecular Medicine, Departments of Orthopedic Surgery, Rush University Medical Center, Chicago, IL 60612, USA
2 Department of Immunology and Biotechnology, University of Pecs, 7643 Pecs, Hungary
Correspondence to: T. T. Glant; E-mail: tglant{at}rush.edu
Proteoglycan (PG) aggrecan-induced arthritis (PGIA) is a murine model of rheumatoid arthritis (RA). Although BALB/c and DBA/2 mice share the same MHC (H-2d) haplotype, the BALB/c strain is susceptible to PGIA, while DBA/2 mice are resistant. Therefore, these two inbred mouse strains provide an opportunity to study arthritis susceptibility factors excluding the effects of MHC-associated genetic components. The goal of this study was to monitor changes in the cellular composition and activation state following intra-peritoneal (i.p.) immunization to induce PGIA; additionally, we sought to identify new susceptibility factors by comparing PG-induced immune responses in BALB/c and DBA/2 mice. Upon i.p. PG injection, resident naive B1 cells are replaced by both T cells and conventional B cells in the peritoneum of BALB/c mice. These peritoneal T cells produce IFN
and IL-17, cytokines shown to be important in RA and corresponding arthritis models. Moreover, peritoneal cells can adoptively transfer PGIA to SCID mice, demonstrating their arthritogenic properties. Our results indicate that repeatedly injected antigen leads to the recruitment and activation of immune cells in the peritoneum; these cells then trigger the effector phase of the disease. The migration and activation of Th1/Th17 cells in the peritoneal cavity in response to PG immunization, which did not occur in the arthritis-resistant DBA/2 strain, may be critical factors of arthritis susceptibility in BALB/c mice.
Keywords: cytokines, peritoneum, rheumatoid arthritis, spleen, T cells
Transmitting editor: A. Falus
Received 20 October 2008, accepted 3 February 2009.