Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers use ’trickery’ to create immune response against melanoma

02.11.2005


Dendritic cell-based therapy uses tumor cells and ’danger’ signals to stimulate 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.

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.

Clare Collins | EurekAlert!
Further information:
http://www.upmc.edu

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>