Anti-CD40 monoclonal antibody ameliorates experimental autoimmune uveoretinitis in mice.

Abstract

OBJECTIVE: To investigate the effects of CD40 on ocular inflammation in experimental autoimmune uveoretinitis (EAU) in B10.RIII mice. ANIMALS STUDIED: EAU-susceptible B10.RIII mice were subcutaneously immunized with interphotoreceptor retinoid-binding protein (IRBP) 161-180 in complete Freund's adjuvant and evaluated clinically and pathologically on days 7, 14, 21, 28, and 35 postimmunization. Anti-CD40 antibody was intraperitoneally injected into mice every other day from days 7 to 14 postimmunization. Phosphate-buffered saline (PBS)-injected EAU mice were used as the controls. PROCEDURES: The frequencies of CD11cCD40dendritic cells (DCs), CD11cMHC-IIDCs, and CD11cCD40MHC-IIDCs in splenocytes were evaluated by flow cytometry on days 0, 7, 14, and 21 after immunization. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in CD11cDCs was assessed by ELISA. IRBP-specific lymphocyte proliferation was assessed using a modified MTT cell proliferation assay. RESULTS: The number of CD11cCD40DCs, CD11cMHC-IIDCs, and CD11cCD40MHC-IIDCs increased at the onset of EAU, peaked at the height of disease severity, and was sustained at a high level until day 21. Treatment with anti-CD40 antibody significantly alleviated clinical and pathological activities related to EAU. Compared with the control mice, antibody-treated EAU mice showed few CD11cCD40DC and CD11cCD40MHC-IIDC frequencies in splenocytes. The anti-CD40 antibody significantly suppressed IRBP-specific lymphocyte proliferation and TNF-α and IL-6 production by DCs in EAU mice. CONCLUSIONS: The increased expression of CD40 and major histocompatibility complex (MHC) class II molecules in the splenocytes of EAU mice were correlated with inflammatory activity. Anti-CD40 treatment can significantly attenuate EAU activity by inhibiting systemic IRBP-specific immune responses.