Interaction of HSV-1 and PRV with cell surface components during infectious entry.

For enveloped viruses, entry into a cell requires binding of virus to receptors on the cell surface followed by endocytosis of the virion or direct fusion of the virion envelope with the cell plasma membrane. Herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV) are alphaherpesviruse and important pathogens for human and swine respectively. HSV-1 has been shown to bind to cell surface heparan sulfate (HS) proteoglycans and enter cells by pH-independent direct fusion with the plasma membrane. The mechanism by which PRV enters cells has not been well studied. The research shows that like HSV-1, PRV enters native swine and non-native monkey cells by pH-independent direct fusion. Interference with PRV infection by HSV-1 gD-expressing human or mouse cells was investigated to explore functions of homologous envelope glycoproteins HSV-1 gD and PRV gp50. These homologous glycoproteins behave differently in mediating interference and other envelope glycoproteins, cell-specific, and species-specific factors are likely involved in herpesvirus interference. This research is the first to show that HSV-1 and PRV use a common cell surface receptor(s) to enter Vero cells. Moreover, it demonstrates that a non-HS and saturable cell surface component is required for HSV-1 and PRV thereby indicating multiple receptors in HSV-1 and PRV entry. HSV-1 envelope glycoproteins gD and gH but not gB, and PRV gp50 were shown to bind to the saturable cell surface receptor(s). Finally, attempts to identify HSV-1 receptor were initiated by developing a virus overlay protein binding assay (VOPBA). A 110 kd protein in highly susceptible HEp-2 cells was shown to bind to HSV-1 specifically. Preliminary results show that this protein is missing in poorly susceptible swine testis (ST) cells. The thesis research extends what is known about the process of HSV-1 entry, provides important new information about PRV entry and, sets a solid foundation for elucidating the nature of the non-HS receptor involved in the HSV-1 and PRV entry.Ph.D.Microbiology and ImmunologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/103806/1/9409751.pdfDescription of 9409751.pdf : Restricted to UM users only