Viruses have evolved various methods for evading the immune system. van Berkel et al . describe a secreted protein, M3, of the murine γ herpes virus (γHVS) that acts as a high affinity, selective chemokine scavenger. Chemokines, which consist of four families (CC, CXC, C, and CX 3 C), are secreted proteins that serve as immune system modulators and chemoattractants. Both bacterially produced M3 and M3 secreted into the medium by infected cells bound several CC- and CXC-type chemokines, as well as lymphotactin (C) and fractalkine (CX 3 C) chemokines, with nanomolar affinity. Furthermore, M3 blocked calcium fluxes stimulated by human chemokines in transfected cells, macrophages, and neutrophils. Thus, M3 might be used therapeutically to block cytokine signaling. van Berkel, V., Barrett, J., Tiffany, H.L., Fremont, D.H., Murphy, P.M., McFadden, G., Speck, S.H., and Virgin, H.W., IV. (2000) Identification of a gammaherpesvirus selective chemokine binding protein that inhibits chemokine action. J. Virol. 74 : 6741-6747. [Abstract] [Full Text]