Human cytomegalovirus chemokine receptor gene US28 is transcribed in latently infected THP-1 monocytes

The human cytomegalovirus (HCMV) US28 gene product, pUS28, is a G protein-c oupled receptor that interacts with both CC and CX3C chemokines. To date, t he role of pUS28 in immune evasion and cell migration has been studied only in cell types that can establish productive HCMV infection. We show that H CMV can latently infect THP-1 monocytes and that during latency US28 is tra nscribed. We also show that the transcription is sustained during different iation of the THP-1 monocytes. Since cells expressing pUS28 were previously shown to adhere to immobilized CX,C chemokines (C. A. Haskell, M. D. Clear y, and I. F. Charo, J. Biol. Chem. 275:34183-34189, 2000), we hypothesize t hat latently infected circulating monocytes express pUS28, thereby enabling adhesion of these cells to CX,C-exposing endothelium. Consequently, the US 28-encoded chemokine receptor may play an important role in dissemination o f latent HCMV.