Advances in immunotherapy research to combat cancer has provided unprecedented treatment success due to the discoveries of two different Nobel Laureates, Dr. James P. Allison (U.S.) and Dr. Tasuku Honjo (Japan). Working independently, they each discovered immune system proteins that are important in self-tolerance and that can be harnessed to kill cancer cells. Checkpoint molecules prevent the immune system from killing the body’s own healthy cells. When checkpoint molecules are encountered by T cells, the cells bearing these molecules are spared attack. However, some cancer cells wear checkpoint molecules, acting as imposters of normal cells to evade attack by T cells.
2018 has flown by, and 2019 is just around the corner! As the New Year approaches, it’s good to look back at just how much has been accomplished in the field of medicine, and wonder what the future holds. As is our tradition at this time of year, we are pleased to present HemaCare’s 10 most popular blogs of the year, and the advances in healthcare that they represent. Enjoy the countdown!
Recent research reveals T cells and Natural Killer (NK) cells may respond to cancer cells differently and could ultimately provide more cancer treatment options.
A leading immunotherapeutic approach to treating cancer involves the use of checkpoint inhibitors. Immune checkpoints are proteins expressed on T cells and are essential for the self-tolerance needed to prevent autoimmunity. When T-cell checkpoint molecules bind to its ligand on cells, the targeted cell is not harmed. These checkpoints are often exploited by tumor cells by possessing checkpoint molecules such as PD-L1 and impeding the immune system’s ability to initiate and carry out an immune attack on the tumor.
Researchers are hoping to develop a cancer vaccine to improve a patient’s immune system so they can destroy the cancer cells.
The objective of therapeutic cancer vaccines is to support and enhance a patient’s immune system to recognize and destroy cancer cells while sparing surrounding normal cells. The first therapeutic immune cell–based cancer vaccine approved by the U.S. Food and Drug Administration is Sipuleucel-T. Administration of this vaccine in patients with hormone-refractory prostate cancer lead to an increase in overall survival. Boosting T-cell responses against antigens that cause a number of diseases has been approached by autologous transfer of dendritic cells. A pilot study was conducted using dendritic cells pulsed with tumor lysate from patients with ovarian cancer. Vaccination of the patients stimulated T-cell responses to the tumor antigen led to an increase in patient survival.
A recent study looked at how checkpoint inhibitors may impact the success of immunotherapy for cancer treatment.
Immune homeostasis is crucial for human and animal survival. The immune system is equipped with cells and factors that maintain a critical balance of signals that prevent immune dysfunction. Pathways that ensure this balance are immune checkpoints, and these are essential for the self-tolerance that prevents autoimmunity. Immune checkpoint proteins modulate T-cell responses to self-proteins and antigens, including tumor antigens. The proteins are expressed on the surface of cancer and cytotoxic T cells, and cancer cells use these to evade attack by T cells.