Deletion of both the C3a and C5a receptors fails to protect against experimental autoimmune encephalomyelitis

• Published in: Neuroscience letters 2009-12, Vol.467 (3), p.234-236
• Main Authors: Ramos, Theresa N., Wohler, Jillian E., Barnum, Scott R.
• Format: Article
• Language: English
• Subjects: Anaphylatoxin receptors; Anaphylatoxins; Animals; Biological and medical sciences; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - metabolism; Cell Movement - immunology; Cerebrospinal fluid. Meninges. Spinal cord; Complement; Complement C3a - genetics; Complement C3a - metabolism; Cytokines - metabolism; Cytokines - secretion; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental - genetics; Encephalomyelitis, Autoimmune, Experimental - immunology; Encephalomyelitis, Autoimmune, Experimental - physiopathology; Experimental autoimmune encephalomyelitis; Female; Fundamental and applied biological sciences. Psychology; Gene Deletion; Genetic Predisposition to Disease - genetics; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Multiple Sclerosis - genetics; Multiple Sclerosis - immunology; Multiple Sclerosis - physiopathology; Nervous system (semeiology, syndromes); Neuroimmunology; Neurology; Receptor, Anaphylatoxin C5a - genetics; Receptors, Complement - genetics; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2009.10.045

Multiple sclerosis (MS) is an autoimmune disease in which inflammation, leukocyte infiltration, and ultimately, demyelination occur as a result of innate and adaptive immune-mediated mechanisms. The pathophysiological role of the complement system, a major component of innate immunity, in the development and progression of experimental autoimmune encephalomyelitis (EAE), the animal model for MS has been extensively examined. Previous studies from our lab have shown that the complement receptor for the anaphylatoxin C3a, but not for C5a plays an important role in EAE. Based on the important contributions of the complement anaphylatoxin receptors to other inflammatory conditions in the CNS, we reasoned that deletion of both receptors may reveal underlying interactions between them that are important to EAE pathology. We performed EAE in C3aR/C5aR double knockout mice (C3aR/C5aR −/−) and observed delayed onset of disease but no attenuation of disease severity compared to wild type mice. Interestingly there was trend toward greater infiltration of CD4 +, but not CD8 + T cells, in C3aR/C5aR −/− mice with EAE, suggesting altered trafficking of these cells. Antigen-specific T cells isolated from C3aR/C5aR −/− mice during acute EAE produced elevated levels of TNF-α, but markedly reduced levels of IFN-γ and IL-12 compared to wild type mice. It remains unclear how the changes in these disease parameters contribute to the loss of the protective effect seen in C3aR −/− mice, however our data indicate a level of cross-modulation between the C3aR and C5aR during EAE.