BACKGROUND: CD200:CD200R interactions deliver immunoregulatory signals. A family of CD200Rs (CD200R1-5) has been described, and engagement of CD200R1 by its ligand CD200 suppresses LPS-induced macrophage cytokine production, decreases alloimmune responses in vivo and in vitro, and suppresses collagen-induced arthritis. METHODS: We generated C57BL/6 mice lacking the genomic exons encoding the extracellular domains of the CD200R1 molecule using transformation of ES cells and explored cell subtypes and immune responses in these mice. RESULTS: Myeloid cells/splenocytes from CD200R1(-/-) mice were not stained in FACS by anti-CD200R1 mAb. Stimulation of splenic tumor necrosis factor-alpha production by lipopolysaccharide was enhanced relative to control (+/+) mice and was not suppressed by addition of exogenous CD200Fc. Modulation of alloreactivity in mixed leukocyte cultures by CD200Fc depended upon CD200R1+ stimulatory cells, although maximal immunoregulation by CD200Fc occurred only when CD200R1+ T responder cells also were used. CD200Fc failed to suppress graft rejection in CD200R1(-/-) mice. CONCLUSION: CD200:CD200R1 plays an immunoregulatory role in vivo.
BACKGROUND:CD200:CD200R interactions deliver immunoregulatory signals. A family of CD200Rs (CD200R1-5) has been described, and engagement of CD200R1 by its ligand CD200 suppresses LPS-induced macrophage cytokine production, decreases alloimmune responses in vivo and in vitro, and suppresses collagen-induced arthritis. METHODS: We generated C57BL/6 mice lacking the genomic exons encoding the extracellular domains of the CD200R1 molecule using transformation of ES cells and explored cell subtypes and immune responses in these mice. RESULTS: Myeloid cells/splenocytes from CD200R1(-/-) mice were not stained in FACS by anti-CD200R1 mAb. Stimulation of splenic tumor necrosis factor-alpha production by lipopolysaccharide was enhanced relative to control (+/+) mice and was not suppressed by addition of exogenous CD200Fc. Modulation of alloreactivity in mixed leukocyte cultures by CD200Fc depended upon CD200R1+ stimulatory cells, although maximal immunoregulation by CD200Fc occurred only when CD200R1+ T responder cells also were used. CD200Fc failed to suppress graft rejection in CD200R1(-/-) mice. CONCLUSION:CD200:CD200R1 plays an immunoregulatory role in vivo.
Authors: Mildred Foster-Cuevas; Tina Westerholt; Mohamed Ahmed; Marion H Brown; A Neil Barclay; Sebastian Voigt Journal: J Virol Date: 2011-04-06 Impact factor: 5.103