The glycosylation status of IFN-inducing viral glycoproteins is a potential determinant of induction efficacy [22] [31] . HSV-1 gD has three potential N-glycosylation sites but lacks O-linked glycosylation. DgH virions, that retain expression of gD, were treated with the endoglycosidase, PNGase F, which removes Nlinked sugars. A long incubation was required as the denaturing buffer was excluded from the reaction to avoid conformational changes that might abrogate virion binding. As previously shown, wild-type virions treated in a similar manner retained infectivity ( Figure S1 ) [22] .