Prevention of experimental autoimmune uveoretinitis by blockade of osteopontin with small interfering RNA.
Osteopontin (OPN) is elevated during the progression of experimental autoimmune uveoretinitis (EAU) in C57BL/6 (B6) mice. Furthermore, EAU symptoms are ameliorated in OPN knockout mice or in B6 mice treated with anti-OPN antibody (M5). Recently, OPN has been shown to promote the Th1 response not only in the extracellular space as a secretory protein but also in cytosol as a signaling component. Thus, we attempted to reduce OPN in both compartments by using a small interfering RNA (siRNA) targeting the OPN coding sequence (OPN-siRNA). EAU was induced in B6 mice by immunization with human interphotoreceptor retinoid-binding protein (hIRBP) peptide sequence 1-20. The OPN- or control-siRNA was administered with hydrodynamic methods 24 h before and simultaneously with immunization (prevention regimen). When plasma OPN levels were quantified following siRNA administration with the prevention regimen, the level in the OPN-siRNA-treated group was significantly lower than that in the control-siRNA-treated group. Accordingly, the clinical and histopathological scores of EAU were significantly reduced in B6 mice when siRNA caused OPN blockade. Furthermore, TNF-alpha, IFN-gamma, IL-2, GM-CSF and IL-17 levels in the culture supernatants were markedly suppressed in the OPN-siRNA-treated group, whereas the proliferative responses of T lymphocytes from regional lymph nodes against immunogenic peptides was not significantly reduced. On the other hand, the protection was not significant if the mice received the OPN-siRNA treatment on day 7 and day 8 after immunization when the clinical symptoms appeared overt (reversal regimen). Our results suggest that OPN blockade with OPN-siRNA can be an alternative choice for the usage of anti-OPN antibody and controlling uveoretinitis in the preventive regimen.
Iwata
Daiju
D
Division of Immunobiology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-0815, Japan.
Kitamura
Mizuki
M
Kitaichi
Nobuyoshi
N
Saito
Yoshinari
Y
Kon
Shigeyuki
S
Namba
Kenichi
K
Morimoto
Junko
J
Ebihara
Akiko
A
Kitamei
Hirokuni
H
Yoshida
Kazuhiko
K
Ishida
Susumu
S
Ohno
Shigeaki
S
Uede
Toshimitsu
T
Onoé
Kazunori
K
Iwabuchi
Kazuya
K
D000818:Animals; D001327:Autoimmune Diseases / Q000097:blood / Q000276:immunology / Q000517:prevention & control*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053495:Osteopontin / Q000037:antagonists & inhibitors* / Q000097:blood; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000494:pharmacology*; D012173:Retinitis / Q000097:blood / Q000276:immunology / Q000517:prevention & control*; D013601:T-Lymphocytes / Q000276:immunology; D014605:Uveitis / Q000097:blood / Q000276:immunology / Q000517:prevention & control*
D016207:Cytokines; D034741:RNA, Small Interfering; C506896:Spp1 protein, mouse; D053495:Osteopontin