Examination of oral cancer tissue for the presence of the proteins ICP 4, ICP 5, ICP 6, ICP 8, and gB of herpes simplex virus type 1.

Although patients with oral cancer have increased levels of antibody to herpes simplex virus type 1, the origin of the antigenic stimulation remains unknown. We have therefore looked for proteins of herpes simplex in oral squamous cell carcinomas by staining frozen sections with monoclonal antibodies to the proteins ICP 4, ICP 5, ICP 6, ICP 8, and gB. No staining was seen of the tumor cells of any of 11 oral cancer cases or of the epithelium of 29 other oral lesions, which included cases of leukoplakia, lichen planus, and aphthous ulcers. Frequent staining of mast cells was seen in the connective tissue associated with oral cancer when ascitic fluid was used as the source of monoclonal antibody, but such staining was not seen when the precipitated IgG fraction was used.