It seems like every week brings a new development in potential immunotherapy treatments for mesothelioma. Some of the breakthroughs come directly from mesothelioma research. Other studies, while they may not directly look at mesothelioma tumors, may end up helping mesothelioma patients.
Immunotherapy research is mesothelioma research, even when mesothelioma patients aren’t directly involved. Immunotherapy drugs attack certain forms of cancer cells, no matter what the cancer type. Because of this, advances in immunotherapy often help cancer patients with several different cancer types.
A new study by researchers at the Swiss Institute for Experimental Cancer Research offers a novel method for harnessing our immune system to fight cancer cells. This study has the potential to lead to advances in mesothelioma research as well.
Immunotherapy Breakthrough Could Impact Mesothelioma Research
Circulating through your body at this very moment is an army of ruthless killers. They have names like white blood cell and killer T cell. This army is constantly vigilant, on the lookout for anything from foreign invaders to damaged cells. Their mission is to isolate and kill off anything that threatens you and they are good at what they do. Your immune system is so fierce that it would attack a fetus in a mother’s womb if your body didn’t suppress it during pregnancy.
Cancer cells are abnormal. Their DNA is damaged; they are mutants who don’t follow the same cycle of reproduction and programmed cell death as normal cells. Why doesn’t your immune system go after these obvious targets and dispose of them?
The answer is that, many times, your natural immunity may catch pre-cancerous cells before they can form into a tumor. But some cancer cells have evolved ways to make themselves invisible to your immune cells. This allows them to grow out of control and make you sick.
Immunotherapy examines the tricks that cancer cells use to avoid your immune system and grow into tumors. Immunotherapy drugs are designed to undermine these tricks and alert your immune cells to the presence of malignant cells.
There has been a great deal of mesothelioma research on immunotherapy drugs that block certain pathways (checkpoint blockers) and some mesothelioma patients have had reductions in their tumors after taking these drugs.
Most current immunotherapy treatments are limited to patients with solid tumors. While mesothelioma most commonly forms as a tumor, some patients have the ‘wet’ type of the disease, in which the cancer forms in little nodes without a solid tumor. In addition, treatments that go after solid tumors may miss free-floating cancer cells that can travel through your body and metastasize into dangerous secondary tumors.
The Swiss study is revolutionary because it used a method to communicate with the immune system that could help patients without solid tumors and might inhibit metastasis. Before we delve into the research, it may be helpful to understand your immune system a bit better.
Mesothelioma Research Terms Explained
After your mesothelioma diagnosis, you might feel like you’re taking a medical course yourself. The terms that scientists and doctors throw around can be confusing to anyone who isn’t an MD.
We are all born with some immunity (the innate immune system), but our bodies have to acquire more immunity over time to survive (the adaptive immune system).
Antigens are molecules that convince your plasma (blood) cells to make antibodies. Each antibody is designed to target a specific pathogen (a virus, bacteria – or a cancer cell).
Our adaptive immune system uses antigens and antibodies to develop new immunities as we are exposed to various germs. That’s why, once you have the mumps, you can’t get it again – your body has learned how to fight it off.
Dendritic cells are like antigen messengers: they take antigens and hand them off to T cells. T cells are a type of white blood cell. Killer T cells (also called cytotoxic T cells or CD8+ T-cells) specialize in killing cancer cells, among other things.
A vesicle is a layer of fluid inside a membrane that acts as a canal to transport tiny stuff between your cells. And exosome is a type of vesicle that is common in your blood.
Chimeric refers to artificial cells that are created in the lab and then placed in your body to perform specific functions. Several recent immunotherapy studies have used chimeric molecules.
‘Cross-Dressing’ and ‘Killers’: Harnessing Immune Cells to Fight Cancer
Earlier studies have demonstrated the possibility of dendritic cell vaccines in fighting cancer. Doctors would remove dendritic cells from your body then load them up with cancer antigens and send them back inside to deliver the antigens to T cells. Unfortunately, this approach has used antigens created in the lab. What immunotherapy teaches us is that each cancerous tumor has its own individual characteristics, so these cultured antigens will only work some of the time.
The Swiss study, which was published in Nature Methods, created a type of chimeric receptor to help dendritic cells pick up cancer antigens through exosomes in the patient’s body and deliver them to killer T cells. The process involved is to remove dendritic cells from a patient, inserting the chimeric receptor, and returning them to the patient’s own body. This way, the T cells learn to attack the cancer cells specifically in that person’s tumor.
The dendritic cells pick up antigens from the tumors and wear them on their surface. This is an unusual and simpler way to give antigens to T cells, which the scientists refer to as “cross-dressing.”
The researchers found that their technique allowed more tumor antigens to transfer onto dendritic cells, where they could then be delivered to killer T cells. Once the T cells receive these antigens, they are able to recognize cancer cells as hostile and develop antibodies to kill them.
Mesothelioma research has moved at a fast pace in recent years, in recognition of the urgent need to find better treatments for this deadly cancer. This study is just a first step in a promising direction. The Swiss research team will continue to pursue this line of inquiry and mesothelioma research may pick up on this exciting new development as well.
We will keep our eye on this work, and report new developments as they occur. If you have a story or new information on mesothelioma research, please share your findings with us. We are always searching for new breakthroughs and appreciate any help you or your family members can provide.