Researchers at the Moffitt Cancer Center have found that delayed tumor growth and enhanced survival of mice bearing melanoma were possible by blocking the reconstitution of myeloid-derived suppressor cells and Tregs (suppressors of anti-tumor activity) after total body irradiation had eliminated them. Blocking myeloid-derived suppressor cells and regulatory T-cell reconstitution improved adoptive T-cell therapy, an immunotherapy designed to suppress tumor activity.
The study appears in the December issue of The Journal of Immunology.
"Melanoma is a leading cause of cancer mortality," said Shari Pilon-Thomas, Ph.D., assistant member of the Immunology Program at Moffitt. "With few nonsurgical options for treating melanoma, immunotherapy, which focuses on the induction of immunity against cancer cells, is a promising approach. However, a major hurdle in developing effective immunotherapies is tumor-induced suppression that can limit the effectiveness of tumor-specific T-cells used in immunotherapy."
Chemotherapy or radiation can induce lymphopenia, the condition of having an abnormally low level of white blood cells. This condition is optimal for adoptive T-cell therapeutic strategies. However, after the induction of lymphopenia, suppressor populations that favor tumor progression begin reconstitution, including regulatory T cells (Tregs) and myeloid derived suppressor cells (MDSC). According to the researchers, tumor-induced suppression can stem from quickly reconstituted Tregs and MDSC.
This knowledge led to their research question, whether blocking the reconstitution of suppressor populations - such as Tregs and myeloid derived suppressor cells - could lead to better immunotherapy in mice bearing melanoma. Mice were treated with docetaxel, a chemotherapeutic drug that targets MDSC, followed by adoptive T cell therapy. In brief, the study demonstrated that when myeloid-derived suppressor cells and Treg reconstitution are blocked, immunotherapy with adoptive T cell transfer is more effective.
"It was important to understand the role of these suppressor populations after the induction of lymphopenia so that we can design more effective immunotherapeutic treatments for melanoma aimed at achieving complete tumor regression," concluded Dr. Pilon-Thomas.
H. Lee Moffitt Cancer Center & Research Institute: http://www.moffitt.usf.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
People who suffer from mental health issues also suffer from its stigma. Portraying mental illness as a good thing helps no one
The inventor of a breakthrough DNA test for Down syndrome says the technology can be used to screen people for cancer.The Hong Kong scientist who invented a simple blood test to show pregnant women if their babies have Down syndrome is now testing a similar technology for cancer.
Dr Jeremy Farrar of Wellcome Trust says international community is belatedly taking actions necessary to stem tide of disease
Miniature stomachs gastric organoids will help in study of ulcers and could be used in future to repair patients stomachs
The story of the vaccines development is just one part of a rich and intertwined history of scientific discovery and controversy
A highly sensitive blood test for Ebola exists, so why isn't it being used to test all returning health workers from West Africa? Because the virus isn't in the blood in the first stages of infection.
Drinking beverages enriched with compounds found in cocoa beans improved older adults' performances on a memory test – but there's a catch
A 700-year-old caribou dropping from northern Canada holds surprisingly well-preserved viruses. There's no evidence the viruses are dangerous, but they are scientifically interesting.
The New England Journal of Medicine published an editorial against quarantining people who have worked with Ebola patients in Africa. Renee Montagne speaks with Dr. Lindsey Baden, one of the authors.
Surgeons in Australia say they have performed the first heart transplant using a "dead heart".