BACKGROUND: Strong evidence supports a role for CD40 ligand (CD40L) as marker and mediator of inflammatory diseases such as atherosclerosis. Despite extensive characterization of CD40, the classic receptor of CD40L, its role in immune defense against inflammatory diseases remains uncertain. The present study aimed to characterize the contribution of CD40 signaling to atherogenesis. METHODS AND RESULTS: Surprisingly, mice deficient in both CD40 and the low-density lipoprotein receptor did not develop smaller lesions in the aortic arch, root, and thoracoabdominal aorta compared with mice deficient only in the low-density lipoprotein receptor that consumed an atherogenic diet for 8 and 16 weeks. By flow cytometry, radioactive binding assays, and immunoprecipitation, we demonstrate that CD40L interacts with the integrin Mac-1, which results in Mac-1-dependent adhesion and migration of inflammatory cells as well as myeloperoxidase release in vitro. Furthermore, mice deficient in CD40L show significantly reduced thioglycolate-elicited invasion of inflammatory cells into the peritoneal cavity compared with mice deficient in CD40 and wild-type controls. Inhibition of Mac-1 in low-density lipoprotein receptor-deficient mice attenuates lesion development and reduces lesional macrophage accumulation. CONCLUSIONS: These observations identify the interaction of CD40L and Mac-1 as an alternative pathway for CD40L-mediated inflammation. This novel mechanism expands understanding of inflammatory signaling during atherogenesis.
BACKGROUND: Strong evidence supports a role for CD40 ligand (CD40L) as marker and mediator of inflammatory diseases such as atherosclerosis. Despite extensive characterization of CD40, the classic receptor of CD40L, its role in immune defense against inflammatory diseases remains uncertain. The present study aimed to characterize the contribution of CD40 signaling to atherogenesis. METHODS AND RESULTS: Surprisingly, mice deficient in both CD40 and the low-density lipoprotein receptor did not develop smaller lesions in the aortic arch, root, and thoracoabdominal aorta compared with mice deficient only in the low-density lipoprotein receptor that consumed an atherogenic diet for 8 and 16 weeks. By flow cytometry, radioactive binding assays, and immunoprecipitation, we demonstrate that CD40L interacts with the integrin Mac-1, which results in Mac-1-dependent adhesion and migration of inflammatory cells as well as myeloperoxidase release in vitro. Furthermore, mice deficient in CD40L show significantly reduced thioglycolate-elicited invasion of inflammatory cells into the peritoneal cavity compared with mice deficient in CD40 and wild-type controls. Inhibition of Mac-1 in low-density lipoprotein receptor-deficient mice attenuates lesion development and reduces lesional macrophage accumulation. CONCLUSIONS: These observations identify the interaction of CD40L and Mac-1 as an alternative pathway for CD40L-mediated inflammation. This novel mechanism expands understanding of inflammatory signaling during atherogenesis.
Authors: Stephen T Bartlett; James F Markmann; Paul Johnson; Olle Korsgren; Bernhard J Hering; David Scharp; Thomas W H Kay; Jonathan Bromberg; Jon S Odorico; Gordon C Weir; Nancy Bridges; Raja Kandaswamy; Peter Stock; Peter Friend; Mitsukazu Gotoh; David K C Cooper; Chung-Gyu Park; Phillip OʼConnell; Cherie Stabler; Shinichi Matsumoto; Barbara Ludwig; Pratik Choudhary; Boris Kovatchev; Michael R Rickels; Megan Sykes; Kathryn Wood; Kristy Kraemer; Albert Hwa; Edward Stanley; Camillo Ricordi; Mark Zimmerman; Julia Greenstein; Eduard Montanya; Timo Otonkoski Journal: Transplantation Date: 2016-02 Impact factor: 4.939
Authors: Jau-Yi Li; Hesham Tawfeek; Brahmchetna Bedi; Xiaoying Yang; Jonathan Adams; Kristy Y Gao; Majd Zayzafoon; M Neale Weitzmann; Roberto Pacifici Journal: Proc Natl Acad Sci U S A Date: 2010-12-27 Impact factor: 11.205
Authors: Guohong Li; John M Sanders; Melissa H Bevard; Zhiqi Sun; James W Chumley; Elena V Galkina; Klaus Ley; Ian J Sarembock Journal: Am J Pathol Date: 2008-03-18 Impact factor: 4.307