Stop-Start Action in NK Cell Activation

Science's STKE  21 May 2002:
Vol. 2002, Issue 133, pp. TW183
DOI: 10.1126/stke.2002.133.TW183


The natural killer (NK) cell receptor LY49H was recently identified as being responsible for rendering certain strains of mice resistant to mouse cytomegalovirus (MCMV). Infection with the virus should alter host proteins that interact with LY49H and lead to NK cell activation. Unexpectedly, Arase et al. (see the Perspective by Vivier and Biron) found that the ligand for LY49H is a type I-anchored glycoprotein encoded by the virus itself. In mice that are resistant to MCMV, the protein m157 activated LY49H+ NK cells, but m157 bound an inhibitory LY49 NK receptor in a susceptible strain of mice. NK cell inhibition through direct interaction between a viral protein and host receptor may have evolved as a viral evasion strategy, which was followed by the evolution of an activatory protein.

H. Arase, E. S. Mocarski, A. E. Campbell, A. B. Hill, L. L. Lanier, Direct recognition of cytomegalovirus by activating and inhibitory NK cell receptors. Science 296, 1323-1326 (2002). [Abstract] [Full Text]

E. Vivier, C. A. Biron, A pathogen receptor on natural killer cells. Science 296, 1248-1249 (2002). [Summary] [Full Text]