The complement system plays a critical role in the development of experimental autoimmune anterior uveitis.
OBJECTIVE
The role of complement in ocular autoimmunity was explored in a experimental autoimmune anterior uveitis (EAAU) animal model.


METHODS
EAAU was induced in Lewis rats by immunization with bovine melanin-associated antigen. Complement activation in the eye was monitored by Western blot for iC3b. The importance of complement to the development of EAAU was studied by comparing the course of intraocular inflammation in normal Lewis rats (complement-sufficient) with cobra venom factor-treated rats (complement-depleted). Eyes were harvested from both complement-sufficient and complement-depleted rats for mRNA and protein analysis for IFN-gamma, IL-10, and interferon-inducible protein (IP)-10. Intracellular adhesion molecule (ICAM)-1 and leukocyte-endothelial cell adhesion molecule (LECAM)-1 were detected by immunofluorescent staining. OX-42 was used to investigate the importance of iC3b and CR3 interaction in EAAU.


RESULTS
There was a correlation between ocular complement activation and disease progression in EAAU. The incidence, duration, and severity of disease were dramatically reduced after active immunization in complement-depleted rats. Complement depletion also completely suppressed adoptive transfer EAAU. The presence of complement was critical for local production of cytokines (IFN-gamma and IL-10), chemokines (IP-10), and adhesion molecules (ICAM-1 and LECAM-1) during EAAU. Furthermore, intraocular complement activation, specifically iC3b production and engagement of complement receptor 3 (CR3), had a significant impact on disease activity in EAAU.


CONCLUSIONS
The study provided the novel finding that complement activation plays a central role in the pathogenesis of ocular autoimmunity and may serve as a potential target for therapeutic intervention.
Jha
Purushottam
P
Department of Ophthalmology, Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
Sohn
Jeong-Hyeon
JH
Xu
Qin
Q
Nishihori
Hiroki
H
Wang
Yali
Y
Nishihori
Saori
S
Manickam
Balasubramanian
B
Kaplan
Henry J
HJ
Bora
Puran S
PS
Bora
Nalini S
NS
D019264:Adoptive Transfer; D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology*; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000378:metabolism; D018925:Chemokines / Q000235:genetics; D003167:Complement Activation / Q000276:immunology*; D003179:Complement C3b / Q000378:metabolism; D003165:Complement System Proteins / Q000502:physiology*; D016207:Cytokines / Q000235:genetics; D004195:Disease Models, Animal; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014606:Uveitis, Anterior / Q000276:immunology*
D015815:Cell Adhesion Molecules; D018925:Chemokines; D016207:Cytokines; D016177:Macrophage-1 Antigen; D012333:RNA, Messenger; D003179:Complement C3b; D003165:Complement System Proteins