Multiple Receptor Interactions Trigger Release of Membrane and Intracellular Calcium Stores Critical for HSV Entry

Natalia Cheshenko,* Wen Liu,* Lisa M. Satlin,* and Betsy C. Herold* ${dagger}$

Departments of ^*Pediatrics and Microbiology, Mount Sinai School of Medicine, New York, NY 10029

Monitoring Editor: Adam Linstedt

HSV harnesses cellular calciumsignaling pathways to facilitate viral entry. Confocal microscopyand small interfering RNA (siRNA) were used to identify thesource of the calcium and dissect the requisite viral-cell interactions.Binding of HSV to human epithelial cells induced no calciumresponse, but shifting the cells to temperatures permissivefor penetration triggered increases in plasma membrane calciumfollowed by a global release of intracellular calcium. Transfectionwith siRNA targeting the proteoglycan, syndecan-2, blocked viralbinding and abrogated any calcium response. Transfection withsiRNA targeting nectin-1, a glycoprotein D receptor, also preventedboth membrane and intracellular calcium responses. In contrast,the membrane response was preserved following transfection withsiRNA targeting integrin ${alpha}$ v, a novel glycoprotein H receptor.The membrane response, however, was not sufficient for viralentry which required interactions with integrin ${alpha}$ V and releaseof inositol-triphosphate receptor-dependent intracellular calciumstores. Thus, calcium plays a critical, complex role in HSVentry.

Address correspondence to: Betsy C. Herold (betsy.herold{at}mssm.edu)