ScienceDaily: "Cytomegaloviruses deploy a novel stealth strategy to subvert immune surveillance"

[Jani]

PLOS. (2019, April 4). Cytomegaloviruses deploy a novel stealth strategy to subvert immune surveillance. ScienceDaily. Retrieved April 6, 2019 from www.sciencedaily.com/releases/2019/04/190404143707.htm

Summary:
Owl monkey cytomegalovirus produces a decoy molecule A43 to evade detection and destruction by immune cells in their hosts, according to a new study. As the authors note, the findings provide a novel example of an immune evasion strategy developed by viruses.

Study:
Martínez-Vicente P, Farré D, Sánchez C, Alcamí A, Engel P, et al. (2019) Subversion of natural killer cell responses by a cytomegalovirus-encoded soluble CD48 decoy receptor. PLOS Pathogens 15(4): e1007658. https://doi.org/10.1371/journal.ppat.1007658

Author summary
In order to evade detection and destruction by cytotoxic lymphocytes and successfully persist within their hosts, cytomegalovirus (CMVs) have evolved a number of genes dedicated to block immune recognition. Certain CMVs and other large DNA viruses encode homologs of the cell-surface molecule CD48, a ligand of the 2B4 receptor involved in regulating the function of cytotoxic lymphocytes. Here, we have investigated for the first time the immunomodulatory potential of one of these viral molecules. We show that A43, a CD48 homolog encoded by owl monkey CMV, is a soluble molecule that exhibits exceptional binding kinetics for 2B4, and is furthermore capable of blocking the interaction with its counter-receptor CD48. Moreover, we reveal how this viral protein interferes with human NK cell-mediated cytotoxicity by inhibiting the immune synapse between human NK cells and target cells. Thus, these findings not only underscore the importance of 2B4-mediated immune responses in controlling CMV infections, but also unveil the shedding of a virally-encoded soluble variant of CD48 as a new viral counteract mechanism for subverting immune surveillance.

Martínez-Vicente P, Farré D, Sánchez C, Alcamí A, Engel P, et al. (2019) Subversion of natural killer cell responses by a cytomegalovirus-encoded soluble CD48 decoy receptor. PLOS Pathogens 15(4): e1007658. https://doi.org/10.1371/journal.ppat.1007658