Entry of simian virus 40 is restricted to apical surfaces of polarized epithelial cells.

Abstract

The uptake of simian virus 40 (SV40) by polarized epithelial cells was investigated by growth of cells on permeable supports and inoculation on either the apical or the basolateral surface. Binding of radiolabeled SV40 occurred on the apical but not the basolateral surfaces of permissive polarized Vero Polarized epithelial cells are characterized by the presence of two plasma membrane domains: the apical domain, which lines the epithelial lumen, and the basolateral domain, which faces underlying tissues in vivo. These two domains are separated by a continuous belt of tight junctional complexes which maintain the unique protein and lipid compositions of each domain (30). Certain enveloped viruses have been shown to enter polarized epithelial cells preferentially from the basolateral domain (7,8). The polarity of viral entry is presumed to be the result of the polarized expression of viral receptors. The entry of a virus exclusively from the apical surface has not been previously reported. We have recently shown that simian virus 40 (SV40), a nonenveloped virus, is released preferentially from the apical surface of polarized epithelial cells (Clayson et al., submitted for publication), and we have investigated the entry of SV40 in the present study.SV40 adsorbs to the cell surface, where it is internalized either individually or in small groups in endocytic vesicles. These virion-containing vesicles are reported to be transported directly to the nucleus and to fuse with the outer nuclear membrane (11,20,23). The virus is then thought to be transported across the inner nuclear membrane (by an unknown mechanism) into the nucleoplasm, where virus uncoating and virus replication occur (2). In order to determine whether the binding of SV40 is polarized in permissive cells grown on permeable supports, an assay for the binding of radiolabeled SV40 virions to cell monolayers was developed. Electron microscopy was also used to demonstrate virus binding to cell surfaces. Productive infection of cells infected from either apical or basolateral surfaces was determined by plaque assay of the progeny virus produced, and viral capsid protein synthesis in cells infected from either apical or basolateral surfaces was analyzed by indirect immunofluorescence. * Corresponding author. MATERIALS AND METHODSCells and virus. Polarized Vero C1008, CV-1, and primary African green monkey kidney (AGMK) cells were obtained and grown as previously described (Clayson et al., submitted). Nonpolarized Vero and polarized Madin-Darby canine kidney (MDCK) cells were purchased from the American Type Culture Collection and were maintained in Dulbecco modified Eagle medium supplemented with 10% newborn calf serum. Purified canine parvovirus was a gift from Sukla Basak. SV40 stocks were prepared and titers were determined as previously described (Clayson et al., submitted). For preparation of purified 3H-labeled SV40 virus, infected monolayers were incubated in leucine-free Eagle medium supplemented with 2% fetal bovine serum and 10 ,uCi of L-[4,5-3H]...

Cell-to-Cell Contact Results in a Selective Translocation of Maternal Human Immunodeficiency Virus Type 1 Quasispecies across a Trophoblastic Barrier by both Transcytosis and Infection

“…The inability of cell-free HIV to transcytose or to infect BeWo cells cannot be ascribed to factors related to cell polarity, as identical results were obtained when cell-free virus was applied either apically or basolaterally or when we attempted to infect unpolarized BeWo cells. This contrasts with findings for other viruses that infect and replicate in epithelia in a polarized manner, such as vesicular stomatitis virus or canine parvovirus (infecting predominantly through the basolateral membrane) (3,27) and measles virus or simian virus 40, which preferentially infects via the apical membrane (5,15).…”

Virus entry into a polarized epithelial cell line (MDCK): similarities and dissimilarities between influenza C virus and bovine coronavirus

“…With polarized epithelial cells, it is generally assumed that the presence of suitable receptors determines whether a virus can enter the cell via the apical and/or the basolateral domain of the plasma membrane. Studies with SV40, for example, have shown that this virus infects polarized cells only from the apical side (Clayson & Compans, 1988). This restriction is reflected in the ability of the virus to bind to the apical, but not to the basolateral domain of the plasma membrane.…”

Infection of a polarized epithelial cell line with wild-type reovirus leads to virus persistence and altered cellular function

“…The cells are capable of transcellular transport across the cytoplasm of a variety of ligands, including viral proteins (Pesonen & Simons, 1983), immunoglobulins (Mostov & Deitcher, 1986) and epidermal growth factor (EGF) (Maratos-Flier et al, 1987). In addition, entry of certain viruses is polarized to either the apical (Clayson & Compans, 1988) or basal (Basak & Compans, 1989) surface.…”