Dramatically stimulates primary monocytes, macrophages, and dendritic cells to produce the inflammatory cytokines interleukin 1-beta, IL-6, monocyte chemoattractant protein 1, and TNF-alpha. The induction of inflammatory cytokine production potentially promotes the cytokine-mediated angiogenic proliferation of KSHV-infected cells. Interacts with human CD200R1. N-glycosylated.