This proposal is to study the process of fusion between cells and Herpes simplex virus (HSV). This is a pH-independent mechanism and is different from pH-dependent endocytosis. The cells to be used are human embryonic lung (HEL) cells, which are highly susceptible to HSV infection, and X cells ?mammalian, non-human primary epithelial cells!, which produce low yields of infectious HSV. It is postulated that two types of attachment by the virus to the cell may be necessary for successful fusion. Heparan sulfate has been shown to be important in attachment and infection of HSV; its presence in X cells will be determined. HEL cells may contain another molecule necessary for fusion which is lacking in X cells; fusions will be made at various cell ratios to see whether levels of infectivity are altered. Additionally, genomic DNA from HEL cells will be transfected into X cells along with a selectible marker, to see if the X cells then become susceptible to HSV. Antibodies which inhibit infection of human cells by HSV will also be prepared. %%% Herpes simplex virus is a human pathogen; other members of the same family are major animal pathogens. Not all cell types are equally susceptible to HSV infection. This proposal is to study the mechanism by which HSV and cells undergo fusion and allow the virus to enter and infect the cells. Two types of attachment sites may be needed for the virus to infect successfully. One component (heparan sulfate) is known to be important in cell-virus attachment; its presence on a cell type which is not very sensitive to the virus will be determined. If a second type of molecule is present on susceptible cells and not on resistant cells, it should be possible to fuse these cells in different ratios by known techniques, then see what level of HSV infection results. DNA from susceptible cells will be inserted into resistant cells, to see whether they become susceptible to infection. Antibodies which block HSV entry into cells will also be prepared. The information will add to knowledge of the general properties which allow membranes to fuse in many cellular processes.
