New study reveals how cannabis suppresses immune functions
Cannabis compounds found to trigger unique immune cells which promote cancer growth
2010-11-25
(Press-News.org) An international team of immunologists studying the effects of cannabis have discovered how smoking marijuana can trigger a suppression of the body's immune functions. The research, published in the European Journal of Immunology, reveals why cannabis users are more susceptible to certain types of cancers and infections.
The team, led by Dr Prakash Nagarkatti from the University of South Carolina, focused their research on cannabinoids, a group of compounds found inside the cannabis plant, including THC (delta-9 tetahydrocannabinol) which is already used for medical purposes such as pain relief.
"Cannabis is one of the most widely used drugs of abuse worldwide and it is already believed to suppress immune functions making the user more susceptible to infections and some types of cancer," said Dr Nagarkatti. "We believe the key to this suppression is a unique type of immune cell, which has only recently been identified by immunologists, called myeloid-derived suppressor cells, MDSCs."
While most immune cells fight against infections and cancers to protect the host, MDSCs actively suppress the immune system. The presence of these cells is known to increase in cancer patients and it is believed that MDSCs may suppress the immune system against cancer therapy, actually promoting cancer growth.
Dr Nagarkatti's team demonstrated that cannabinoids can trigger a massive number of MDSCs through activation of cannabinoid receptors. This research reveals, for the first time, that marijuana cannabinoids may suppress the immune system by activating these unique cells.
"These results raise interesting questions on whether increased susceptibility to certain types of cancers or infections caused from smoking marijuana results from induction of MDSCs," said Nagarkatti. "MDSCs seem to be unique and important cells that may be triggered by inappropriate production of certain growth factors by cancer cells or other chemical agents such as cannabinoids, which lead to a suppression of the immune system's response."
In a related study, also published in the European journal of Immunology, Dr Christian Vosshenrich from the Institut Pasteur in Paris, reveals that when cancer cells grow they produce a molecule called interleukin-1 β (IL-1β), which also triggers MDSCs. This study identifies how MDSCs produced during cancer growth also weaken the ability of immune cells to kill cancer cells.
"Marijuana cannabinoids present us with a double edged sword," concluded Dr Nagarkatti. "On one hand, due to their immunosuppressive nature, they can cause increased susceptibility to cancer and infections. However, further research of these compounds could provide opportunities to treat a large number of clinical disorders where suppressing the immune response is actually beneficial."
INFORMATION: END
ELSE PRESS RELEASES FROM THIS DATE:
2010-11-25
As the eurozone continues to wobble, new analysis of countries' economic interconnectedness finds that some of the countries with the greatest potential to cause a global crash have surprisingly small gross domestic production.
Using data from Bureau Van Dijk - the company information and business intelligence provider - to assess the reach and size of different countries' economies, and applying the Susceptible-Infected-Recovered (SIR) model, physicists from universities in Greece, Switzerland and Israel have identified the twelve countries with greatest power to spread ...
2010-11-25
Fifty-seven laboratories from 29 countries volunteered to put their measuring competence to the test. Each laboratory received a sample without knowing the levels of heavy metals present, and was asked to measure and report the values back to the JRC.
The good results should enhance consumers' confidence, as maximum levels of lead, cadmium and total mercury in seafood are regulated by EU law and it has been proven that most participants are able to correctly measure them. In addition, this comparison has highlighted other issues, such as the apparent dependency of the ...
2010-11-25
About 30% of breast cancer patients have tumours that show rapid growth and invasion through the body. A common denominator in all of these cases is the presence of a large number of Her2 proteins in tumour cellular membranes. Consequently, these aggressive tumours are referred to as HER2+. Scientists working in the Metastasis Laboratory (MetLab) at IRB Barcelona headed by ICREA researcher Roger Gomis, have described the molecular mechanism that induces HER2+ tumours to ignore the signals that protect cells from excessive growth. The study is published this week in the ...
2010-11-25
In the wake of devastating cholera outbreaks in refugee camps in earthquake-wracked Haiti, a group of leading experts from Harvard Medical School, George Washington University, and the International Vaccine Institute (IVI) have urged the United States to create an emergency stockpile of cholera vaccines for future humanitarian use.
"The costs to the U.S. of creating and maintaining a stockpile of several million doses of cholera vaccine would be low," said the experts in an article published online first on November 24 in The New England Journal of Medicine (NEJM). "But ...
2010-11-25
A new process for creating a personalized vaccine may become a crucial tool in helping patients with colorectal cancer develop an immune response against their own tumors. This dendritic cell (DC) vaccine, developed at Dartmouth and described in a research paper published this week in the journal Clinical Cancer Research, was used after surgical resection of metastatic tumors to try to prevent the growth of additional metastases.
"The results of the study suggest a new way to approach cancer treatment," said Richard Barth Jr., MD, Chief of General Surgery at Dartmouth-Hitchcock ...
2010-11-25
The search is on for insects, mites, microbes or nematodes that could be used in a biologically based approach to controlling silverleaf nightshade, an invasive weed from the Americas that has spread to southern Europe, Africa, India, Australia and elsewhere.
According to U.S. Department of Agriculture (USDA) entomologist Walker Jones, the perennial weed, Solanum elaeagnifolium, is being targeted for its ability to outcompete native plants, reduce crop yields and diminish pasture productivity. Its orange, toxin-producing berries can also poison livestock.
Severe infestations ...
2010-11-25
London, UK, 24 November 2010 – Research from the Laboratory of Psychiatry and Experimental Alzheimers Research (http://www2.i-med.ac.at/psychlab/) at the Medical University Innsbruck (Austria) demonstrated that chronic high fat cholesterol diet in rats exhibited pathologies similar to Alzheimer's disease. The results were published in Molecular Cellular Neuroscience (45(4):408-417, 2010) with lead author Dr. Christian Humpel. The study was co-authored by PhD students, Celine Ullrich and Michael Pirchl, from the same Laboratory.
Alzheimer's disease is a severe neurodegenerative ...
2010-11-25
Mildew infections not only cause unsightly vegetable patches, they can also result in extensive crop failure. Interestingly, the processes involved in infections with this garden pest are similar to those involved in fertilisation. Scientists from the Max Planck Institute for Plant Breeding Research in Cologne and the University of Zurich have identified two proteins in the model plant species Arabidopsis thaliana that are necessary for both fertilisation and infection with powdery mildew. This explains why mildew-resistant plants, in which these genes are mutated, are ...
2010-11-25
Leading experts from the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and the International Osteoporosis Foundation (IOF) have published a timely position paper on the association between subtrochanteric femoral (upper thigh bone) fractures and long-term treatment with bisphosphonates.
Bisphosphonates are the most common drug therapy for osteoporotic fracture prevention, prescribed to millions of people around the world. Concern among doctors and patients has arisen following recent media reports that cite a possible association ...
2010-11-25
CAMBRIDGE, Mass. -- In a new study to be published in the Nov. 25 issue of Nature, MIT cancer biologists show that restoring the protein p53's function in mice with lung cancer has no effect early in tumor development, but restoring the function later on could prevent more advanced tumors from spreading throughout the body.
Cancer researchers have known since the 1980s that p53 plays a critical role in protecting cells from becoming cancerous. P53 is defective in about half of all human cancers; when it functions correctly, it appears to suppress tumor formation by preventing ...
LAST 30 PRESS RELEASES:
[Press-News.org] New study reveals how cannabis suppresses immune functions
Cannabis compounds found to trigger unique immune cells which promote cancer growth
