Research on immune cells “exhausted” by chronic viral infection provides clues on how to refine cancer immunotherapy. The results were published Tuesday, Dec. 3 in Immunity.
Scientists at Emory Vaccine Center, led by Rafi Ahmed, PhD, have learned about exhausted CD8 T cells, based on studying mice with chronic viral infections. In the presence of persistent virus or cancer, CD8 T cells lose much of their ability to fight disease, and display inhibitory checkpoint proteins Read more
Emory immunologists have identified a potential target for treatments aimed at reducing mortality in sepsis, an often deadly reaction to infection.
2B4 is an inhibitory molecule found on immune cells. You may have heard of PD1, which cancer immunotherapy drugs block in order to re-energize the immune system. 2B4 appears to be similar; it appears on exhausted T cells after chronic viral infection, and its absence can contribute to autoimmunity.
In their new paper in Journal of Immunology, Mandy Ford, Craig Coopersmith and colleagues show that 2B4 levels are increased on certain types of T cells (CD4+ memory cells) in human sepsis patients and in a mouse model of sepsis called CLP (cecal ligation + puncture). Genetically knocking out 2B4 or blocking it with an antibody both reduce mortality in the CLP model. The effect of the knockout is striking: 82 percent survival vs 13 percent for controls.
How does it work? When fighting sepsis, 2B4 knockout animals don’t have reduced bacterial levels, but they do seem to have CD4+ T cels that survive better. CD4+ T cells, especially memory cells, get killed in large numbers during sepsis, and this is thought to contribute to mortality. Read more
Partly, that’s because decent avenues for treatment exist for most types of breast cancer, with improvements in survival since the 1980s. Immunotherapy’s successes have been more dramatic for types of cancer against which progress had been otherwise meager, such as lung cancers and metastatic melanoma.
Winship oncologist Jane Meisel, MD with patient
However, for “triple-negative” breast cancer (TNBC) in particular, immunotherapy could be a good match, because of the scarcity of targeted treatments and because TNBC’s genomic instability may be well-suited to immunotherapy.
Winship oncologists Jane Meisel and Keerthi Gogineni inform Lab Land that several early-phase clinical studies open to breast cancer patients, testing “checkpoint inhibitor” agents such as PD-1 inhibitors, are underway. More are pending.
Meisel’s presentation at Winship’s Sea Island retreat says that immunotherapy is “not yet ready for prime time, but a very promising experimental approach for a subset of patients for whom current therapies are not sufficient. We need to better understand which subsets of patients are most likely to benefit, and how we can use other therapies to enhance efficacy in patients who don’t initially respond.”
The big news from the recent American Society of Clinical Oncology meeting has been largelyÂ about immunotherapy drugs, also known as checkpoint inhibitors. These drugs have been shown to be effective in prolonging life in patients with some types of cancer, such as lung cancer and melanoma, but not others, such as colorectal and prostate cancer.
Lab Land asked oncologist Bradley Carthon and immunology researcher Haydn Kissick why. Both Carthonâ€™s clinical work and Kissickâ€™s lab research on prostate cancer are featured in the new issue of Winship magazine,Â but the prostate feature just touches on checkpoint inhibitors briefly.
Carthon says the reason checkpoint inhibitors havenâ€™t moved the needle with prostate cancer is â€œlikely due to the absence of infiltration of the prostatic tissue by tumor-associated lymphocytes.â€
Checkpoint inhibitors are supposed to unleash the immune system, but if the immune cells arenâ€™t in contact with the cancer cells so that the drugs can spur them into action, they wonâ€™t help much. Carthon says: â€œThe answer may be to â€˜primeâ€™ the prostate with an agent, then introduce the checkpoint inhibitors.â€ Read more
Gina Kolata has a section front story in Tuesday’s New York Times exploring the potential of a relatively new class of anticancer drugs. The drugs break through “shields” built by cancers to ward off the threat posed by the patient’s immune system. Many are based on blocking PD-1, an immune regulatory molecule whose importance in chronic infections was first defined by Emory’s Rafi Ahmed.
Let’s take a moment to examine some of the roots of this story.Â Rafi Ahmed didnâ€™t set out to study cancer. For the last two decades, he and his colleagues have been studying T cells, parts of the immune system that are critical for responding to infections. Read more
Can it really be possible to transform a person’s own cells into a weapon against various forms of disease? And what if those very cells could be retrained to attack cancer cells or to prevent autoimmune diseases?
Answers to these questions and many more are about to soon be realized, as Emory University Hospital will serve as the launch site for the very appropriately-named EPIC (Emory Personalized Immunotherapy Center).
The new Center, which is the creation of Dr. Jacques Galipeau, MD, professor of hematology and medical oncology & pediatrics of Emory University, will soon be operational after final touches have been put on construction of the lab. This cell processing facility will foster development of novel personalized cellular therapies for Emory patients facing catastrophic ailments and unmet medical needs.
According to Galipeau, the premise of EPIC and its overlying mission will focus on cellular and biological therapies that use a patientâ€™s own cells as a weapon to seek and destroy cells that actually make a person sick. In partnership with the Winship Cancer Institute of Emory University, Childrenâ€™s Healthcare of Atlanta, Aflac Cancer & Blood Disorders Center and the Emory School of Medicine, EPIC seeks to improve the health of children and adults afflicted with cancer and immune disease.
â€œFirst and foremost, we seek to bring a level of care and discovery that is first in Georgia, first in human and first in child. Blood and marrow derived cells have been used for more than a quarter century to treat life threatening hematological conditions and are now established therapies worldwide. More recently, the use of specific adult somatic cells from marrow, blood and other tissues are being studied in cellular medicine of a wide array of ailments including heart, lung, neurological and immune diseases,â€ says Galipeau. â€œThe use of blood borne immune cells can also be exploited for treatment of cancer, autoimmune disease, organ transplantation and chronic viral illnesses such as HIV.â€
Galipeau said that once operational, EPIC willÂ begin by working with Crohnâ€™s disease in pediatric and adult patients, an inflammatory bowel disease. Symptoms of Crohnâ€™s disease include severe abdominal pain, diarrhea, fever, weight loss, and the inability for a child to properly grow. Resulting bouts of inflammation may also affect the entire digestive tract, including the mouth, esophagus and stomach.Â In some cases, a radical surgery involving the removal of part of the lower intestinal tract is required.
â€œThere is no current answer for what specifically causes Crohnâ€™s disease, nor is there a cure. But we hope that through our research and efforts, we will be able to first target the inflammatory mechanisms in these patients through immunotherapy, and in turn reduce the amount of flare-ups and limitÂ the damage that occurs from this disease,â€ says Galipeau.
Galipeau says the EPIC program could represent a powerful cornerstone to the launch and the development of an entirely new, Emory-based initiative which bundles the strengths of the School of Medicine, Emory University Hospital, Children’s Healthcare of Atlanta, and many Woodruff Health Sciences Center centers of excellence,â€ says Galipeau.
â€œMy ultimate goal is to elevate the biomedical scientific and scholarly enterprise to aÂ higher level – making a difference in the lives of people. The EPIC program and multi-levels of support could be a fundamental underpinning to our success.â€