UniSci - Daily University Science News
Home Search
 

clear.gif (52 bytes)


New Vaccine Targets Cancer-Causing Strains Of HPV

An estimated 20 million Americans are infected with human papilloma virus (HPV), a virus that is well known for causing genital warts -- but also accounts for over 95 percent of cervical cancer cases.

Cervical intraepithelial neoplasia (CIN) lesions, which precede most if not all cases of cervical cancer, occur in over 50,000 women in the United States each year.

Currently, CIN is detected by PAP smear and treated by surgical removal of the pre-cancerous lesions, a costly procedure that may result in reproductive complications and requires continual post-surgery monitoring for recurrence.

Epimmune Inc. announced Tuesday that Company scientists, in collaboration with Loyola University, Chicago; Leiden University Medical Center, The Netherlands, and University of Wales College of Medicine, Wales, UK, have identified new vaccine targets for cancer-causing strains of HPV.

The scientists report in today's issue of the Journal of Clinical Cancer Research the discovery of four epitopes (protein fragments) from the virus that can induce a cellular immune response in human cells in vitro and may lead to an effective vaccine for treatment and prevention of the pre-cancerous lesions that develop into cervical cancer.

Epimmune is developing a vaccine that is designed to bolster the immune system against HPV, potentially providing a new way to treat and prevent both CIN and cervical cancer.

"Previous research has indicated that a cellular immune response led by cytotoxic T cells is capable of controlling tumor growth and destroying virus-infected cells in HPV-infected patients," said Alessandro Sette, Ph.D., Vice President and Chief Scientific Officer at Epimmune. "Our research shows that it may be possible to emulate this successful immune response with a vaccine that consists of epitopes from several cancer-causing strains of HPV."

There are over 70 identified types of HPV, but a relatively few high-risk strains, including HPV-16 and HPV-18, are known to cause CIN and cervical cancer.

Using Epimmune's proprietary Epitope Identification System™, the Epimmune scientists have identified epitopes predicted to activate cytotoxic T cells (CTLs) from several proteins of most cancer-causing HPV strains.

The current study showed that four epitopes from HPV-18, three derived from E6 and one derived from E7, were highly immunogenic using human cells in vitro, meaning they induce a CTL response.

Research by others has indicated that E6 and E7 proteins are "oncoproteins" that are responsible for the transformation of HPV-infected cells into CIN and cancer cells. Epimmune believes that a vaccine based on epitopes derived from these proteins may provide strong therapeutic benefit by teaching the immune system to recognize and attack HPV-infected cells at all stages of pre-cancerous and cancerous development.

"An effective vaccine to treat CIN and cervical cancer must target multiple cancer-causing strains of HPV," said Robert Chesnut, Executive Vice President, R&D at Epimmune. "Epimmune's approach directly addresses this challenge by combining epitopes from multiple virus strains into a single vaccine to combat all of the HPV strains frequently associated with causing cancer."

"Recently completed clinical trials of an HPV epitope-based vaccine have shown the potential benefit of this approach to treat CIN," said W. Martin Kast, Ph.D., Professor of Microbiology, Immunology and Pharmacology at Loyola University Chicago Stritch School of Medicine and Director of the Cancer Immunology Program at the Cardinal Bernardin Cancer Center of Loyola University Medical Center. "The conformation of additional HPV epitopes, such as those identified in the current study, is important in creating an effective vaccine."

Dr. Kast is the senior author of the HPV epitope identification study entitled "Human T-cell responses to HLA-A restricted high binding affinity peptides of HPV-18 proteins E6 and E7", which appears today in the Journal of Clinical Cancer Research (Volume 7, Issue 3, Supplement, March 2001).

[Contact: Laura Hansen]

28-Mar-2001

 

 

 

 

clear.gif (52 bytes)

Add the UniSci Daily Java News Ticker to Your Site or Desktop.
Click for a demo and more information.

 

HOME | ARCHIVES | ABOUT | PIOs | BYLINES | WHY SCIENCE | WHY UNISCI | PROSTATE | POLIO

Please direct website technical problems or questions to webmaster@unisci.com.

Copyright © 1995-2001 UniSci. All rights reserved.