ACCESSORY HUMAN CYTOMEGALOVIRUS GLYCOPROTEIN US9 IN THE UNIQUE SHORT COMPONENT OF THE VIRAL GENOME PROMOTES CELL-TO-CELL TRANSMISSION OF VIRUS IN POLARIZED EPITHELIAL-CELLS

Human cytomegalovirus (CMV) encodes accessory glycoproteins that are d ispensable for virus growth in nonpolarized cells in culture. We repor t that CMV deletion mutants lacking the gene fur accessory glycoprotei n US9 in the unique short component of the viral genome are impaired i n plaque formation in polarized human retinal pigment epithelial (ARPE -19) cells. Comparison of CMV deletion mutants in US9 with herpes simp lex virus type 1 deletion mutants lacking glycoproteins gE and gI show ed that both of these mutants are impaired in altering junctional comp lexes and increasing paracellular permeability in polarized ARPE-19 ce lls cultured on permeable filter supports. Results of functional studi es indicate that CMV US9 and homologs of gE have analogous roles in pr omoting virus spread across lateral membranes of polarized epithelial cells.