| First Author | Carlucci F | Year | 2016 |
| Journal | J Immunol | Volume | 196 |
| Issue | 4 | Pages | 1488-94 |
| PubMed ID | 26773156 | Mgi Jnum | J:323377 |
| Mgi Id | MGI:6880425 | Doi | 10.4049/jimmunol.1401009 |
| Citation | Carlucci F, et al. (2016) C1q Modulates the Response to TLR7 Stimulation by Pristane-Primed Macrophages: Implications for Pristane-Induced Lupus. J Immunol 196(4):1488-94 |
| abstractText | The complement component C1q is known to play a controversial role in the pathogenesis of systemic lupus erythematosus, but the underlying mechanisms remain poorly understood. Intraperitoneal injection of pristane induces a lupus-like syndrome whose pathogenesis implicates the secretion of type I IFN by CD11b(+) Ly6C(high) inflammatory monocytes in a TLR7-dependent fashion. C1q was also shown to influence the secretion of IFN-alpha. In this study, we explored whether C1q deficiency could affect pristane-induced lupus. Surprisingly, C1qa(-/-) mice developed lower titers of circulating Abs and milder arthritis compared with the controls. In keeping with the clinical scores, 2 wk after pristane injection the peritoneal recruitment of CD11b(+) Ly6C(high) inflammatory monocytes in C1qa(-/-) mice was impaired. Furthermore, C1q-deficient pristane-primed resident peritoneal macrophages secreted significantly less CCL3, CCL2, CXCL1, and IL-6 when stimulated in vitro with TLR7 ligand. Replenishing C1q in vivo during the pristane-priming phase rectified this defect. Conversely, pristane-primed macrophages from C3-deficient mice did not show impaired cytokine production. These findings demonstrate that C1q deficiency impairs the TLR7-dependent chemokine production by pristane-primed peritoneal macrophages and suggest that C1q, and not C3, is involved in the handling of pristane by phagocytic cells, which is required to trigger disease in this model. |
