Pattern recognition scavenger receptor SRA/CD204 down-regulates Toll-like receptor 4 signaling-dependent CD8 T-cell activation.
Class A scavenger receptor (SRA), also known as CD204, has been shown to participate in the pathogenesis of atherosclerosis and the pattern recognition of pathogen infection. However, its role in adaptive immune responses has not been well defined. In this study, we report that the lack of SRA/CD204 promotes Toll-like receptor (TLR)4 agonist-augmented tumor-protective immunity, which is associated with enhanced activation of CD8(+) effector T cell and improved inhibition of tumor growth. Dendritic cells (DCs) deficient in SRA/CD204 display more effective immunostimulatory activities upon TLR4 engagement than those from wild-type counterparts. Silencing of SRA/CD204 by RNA interference improves the ability of DCs to prime antigen-specific CD8(+) T cells, suggesting that antigen-presenting cells, for example, DCs, play a major role in SRA/CD204-mediated immune modulation. Our findings reveal a previously unrecognized role for SRA/CD204, a non-TLR pattern recognition receptor, as a physiologic negative regulator of TLR4-mediated immune consequences, which has important clinical implications for development of TLR-targeted immunotherapeutic intervention.
Yi
Huanfa
H
Department of Cellular Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Yu
Xiaofei
X
Gao
Ping
P
Wang
Yanping
Y
Baek
Sun-Hee
SH
Chen
Xing
X
Kim
Hyung L
HL
Subjeck
John R
JR
Wang
Xiang-Yang
XY
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002460:Cell Line; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000276:immunology; D015536:Down-Regulation / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009369:Neoplasms / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D034622:RNA Interference; D051117:Scavenger Receptors, Class A / Q000172:deficiency / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000276:immunology*
C495140:Msr1 protein, mouse; D051117:Scavenger Receptors, Class A; D051197:Toll-Like Receptor 4; D010047:Ovalbumin