Source: www.medscape.com Author: staff Immunization with a vaccine that targets the E6 and E7 oncoproteins of human papillomavirus-16 (HPV-16) prevents mice with HPV-16-positive head and neck squamous cell cancers (HNSCCs) from expressing these two oncoproteins by mounting a potent immune response. The vaccine may become part of a treatment regimen, along with surgery, chemotherapy or radiotherapy, in patients with HPV-16-positive HNSCCs, investigators report in the December issue of the Archives of Otolaryngology, Head and Neck Surgery. Dr. John H. Lee and colleagues at the Veterans Administration Medical Center in Iowa City generated an adenoviral recombinant vaccine expressing HPV-16 E6/E7 oncoproteins (adenovirus 5 (Ad5) E6/E7). Mice inoculated with the vaccine "completely cleared E6/E7-expressing tumor cells implanted 2 weeks after immunization." (Dr. Lee is now at the Sanford School of Medicine, University of South Dakota, Sioux Falls.) "A time course of interferon-gamma response showed that E6/E7-specific interferon-gamma production is significantly increased in the first 2 weeks after administration of the vaccine and is substantially maintained for up to 70 days," the investigators report. "At all dosages of vaccine, mice inoculated with Ad5 E6/E7 completely cleared E6/E7-expressing tumor cells implanted 2 weeks after either intratracheal or submucosal inoculation, with significant E6/E7-specific interferon-gamma production," the team reports. "Inoculated mice cleared E6/E7-expressing tumor 70 days after implantation." "In accord with this, our data show that immunization with HPV-16 E6/E7 is an effective method for protecting a host from E6/E7-expressing HNSCCs via generation of a potent immune response," Dr. Lee and colleagues write. "Therapeutic vaccines may [...]