Featured Research

from universities, journals, and other organizations

Researchers Use 'Trickery' To Create Immune Response Against Melanoma

Date:
November 1, 2005
Source:
University of Pittsburgh Medical Center
Summary:
A new type of immunotherapy in which dendritic cells are tricked into action against cancer when they are exposed to harmless pieces of viruses and bacteria is described in the November issue of Cancer Research. In the study, University of Pittsburgh researchers describe the creation of an animal model of an immunotherapy approach that, first used in cancer patients, uses a patient's own tumor cells to stimulate anti-tumor immunity.

A new type of immunotherapy in which dendritic cells are tricked into action against cancer when they are exposed to harmless pieces of viruses and bacteria is described in the November issue of Cancer Research. Dendritic cells, the pacemakers of the immune system, are known to play a vital role in the initiation of the immune response but are often eluded by cancer.

Related Articles


In the study, University of Pittsburgh researchers describe the creation of an animal model of an immunotherapy approach that, first used in cancer patients, uses a patient's own tumor cells to stimulate anti-tumor immunity. The discovery of the animal model will enable researchers to more fully understand and develop the approach.

"Cancer cells are very adept at camouflaging themselves and hiding from the immune system and this makes most cancers, including melanomas and lymphomas of the skin, extremely challenging to treat with existing immunotherapies," said Louis D. Falo, M.D., Ph.D., professor and chairman of the department of dermatology at the University of Pittsburgh School of Medicine. "While we know that dendritic cells are necessary to activate a response against cancer as the first cells to present antigens to other cells of the immune system, they are often ineffective because they fail to recognize growing cancers as dangerous. What we describe is an immunotherapy approach that activates dendritic cells by using an external stimulus that mimics danger. This alerts the cells to activate a type of immune response that is particularly important for fighting cancer."

In the study, melanoma cells and dendritic cells from mice were removed, combined together in a culture dish and exposed to pieces of viruses and bacteria. The researchers used the most aggressive mouse melanoma tumor, B16, which has multiple mechanisms to escape the immune system that are similar to those used by human cancers. They found that the dendritic cells were able to extract antigens directly from tumor cells. By exposing the antigen-bearing dendritic cells to harmless pieces of bacteria and virsuses that they preceived as dangerous, the researchers "tricked" them into recognizing the tumor as dangerous as well. The alerted cells were then injected back into the mice where they successfully activated a particular T-cell response important for fighting tumors. That response, called Th1, led to a significant reduction in tumor growth in the mice.

"Typically, tumors are able to grow in part by convincing the immune system that they are normal. Our goal was to mimic danger to wake up the dendritic cells and program them to stimulate the right type of immune response against the patients' own tumor cells," said Dr. Falo.

The researchers further discovered that the Th1 response was enough to stop tumor growth on its own, indicating the importance of Th1-type immunity for tumor therapy. Prior to their discovery, researchers believed that a Th1 response was important, but that it worked primarily by activating another type of T-cell called a cytotoxic T-cell (CTL). These results suggest that it may be important to monitor Th1-type immunity in addition to CTL immunity when evaluating patients' responses to immunotherapy.

Interestingly, Dr. Falo has already found this approach to be successful in a preliminary study in cancer patients. But further progress has been hindered by the length of time and expense involved in such a clinical trial. Unlike most therapy advances that are developed in animal models and then translated to patients, the "danger" signals used in this approach were developed using models based on human tissue. He believes that the creation of this animal model will enable further development of immune approaches to melanoma and other cancers, bringing new treatment options to patients who have failed available therapies.

Melanoma is the most serious form of skin cancer. Although it accounts for only 4 percent of all skin cancer cases, it causes most skin cancer-related deaths. Lymphomas of the skin, including cutaneous T-cell lymphomas, are diagnosed in approximately 16,000 to 20,000 people in the United States each year and are often difficult to diagnose in early stages.

###

This study was funded by a grant from the National Cancer Institute. Collaborators on the study include University of Pittsburgh researchers David A. Hokey; Adriana T. Larregina, M.D., Ph.D.; Geza Erdos, Ph.D.; and Simon C. Watkins, Ph.D.


Story Source:

The above story is based on materials provided by University of Pittsburgh Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

University of Pittsburgh Medical Center. "Researchers Use 'Trickery' To Create Immune Response Against Melanoma." ScienceDaily. ScienceDaily, 1 November 2005. <www.sciencedaily.com/releases/2005/11/051101075711.htm>.
University of Pittsburgh Medical Center. (2005, November 1). Researchers Use 'Trickery' To Create Immune Response Against Melanoma. ScienceDaily. Retrieved January 30, 2015 from www.sciencedaily.com/releases/2005/11/051101075711.htm
University of Pittsburgh Medical Center. "Researchers Use 'Trickery' To Create Immune Response Against Melanoma." ScienceDaily. www.sciencedaily.com/releases/2005/11/051101075711.htm (accessed January 30, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, January 30, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama To Outline New Plan For Personalized Medicine

Obama To Outline New Plan For Personalized Medicine

Newsy (Jan. 30, 2015) President Obama is expected to speak with drugmakers Friday about his Precision Medicine Initiative first introduced last week. Video provided by Newsy
Powered by NewsLook.com
Oxfam Calls for Massive Aid for Ebola-Hit West Africa

Oxfam Calls for Massive Aid for Ebola-Hit West Africa

AFP (Jan. 29, 2015) Oxfam International has called for a multi-million dollar post-Ebola "Marshall Plan", with financial support given by wealthy countries, to help Guinea, Sierra Leone and Liberia to recover. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Are We Winning The Fight Against Ebola?

Are We Winning The Fight Against Ebola?

Newsy (Jan. 29, 2015) The World Health Organization announced the fight against Ebola has entered its second phase as the number of cases per week has steadily dropped. Video provided by Newsy
Powered by NewsLook.com
Calif. Health Officials Campaign Against E-Cigarettes

Calif. Health Officials Campaign Against E-Cigarettes

Newsy (Jan. 29, 2015) The California Health Department says e-cigarettes are a public health risk for both smokers and those who inhale e-cig smoke secondhand. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins