FINDINGS
A new study published in Science Immunology points to a promising therapeutic approach for future cancer treatments based on natural killer cells (NK), which are immune cells that bind to tumor cells and destroy them.
City of Hope scientists created a knockout mouse model for a protein called XBP1s to explore the molecule’s effect on NK cells and its role in fighting cancer. Earlier studies showed that XBPIs strengthened the survival of NK cells, but precisely how was unclear.
The team identified a previously unknown mechanism in which interleukin-15 (IL-15) — a protein naturally made by cells in response to pathogens — interacts with XBP1 to launch a series of events that boost NK cells’ survival and their ability to cause tumor change.
First, XBP1s increases NK cells’ response to a survival gene called Pim2. Next, XBP1s interacts with a transcription factor called T-bet to promote the production of a protective cytokine that enhances NK cells’ function and anti-tumor immunity. Conversely, low levels of XBP1s impair NK cell functions and anti-tumor immunity.
BACKGROUND
City of Hope’s team previously identified XBP1s as an essential transcription factor downstream of IL-15 and AKT signaling, a pathway that promotes human NK cell survival and functions. However, the target genes downstream of XBP1s in NK cells — as well as how XBP1s regulates NK cell survival and function — remained unknown.
IMPACT
In immunotherapy, NK cells have emerged as safe and promising therapies for patients with certain cancers. Scientists have found it challenging, though, to enhance NK cells’ cytotoxicity to tumors and long duration in patients undergoing treatment.
In this study, the authors demonstrated that XBP1s plays a critical role in controlling IL-15-mediated NK cell survival in vitro and in vivo.
AUTHORS
Lead authors Jianhua Yu, Ph.D. and Michael Caligiuri, M.D., are available for interviews. At City of Hope, Yu is founding director of the Natural Killer Cell Biology Research Program within the Cellular Immunotherapy Center, a professor of hematology and hematopoietic cell transplantation and a member of the Hematologic Malignancies Research Institute. Caligiuri is the president of City of Hope National Medical Center and the Deana and Steve Campbell Physician-in-Chief Distinguished Chair.
FUNDING
The research was supported by grants from the National Cancer Institute and The Leukemia & Lymphoma Society.
MEDIA CONTACT
Letisia Marquez, [email protected], 626-476-7593
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About City of Hope
City of Hope’s mission is to deliver the cures of tomorrow to the people who need them today. Founded in 1913, City of Hope has grown into one of the largest cancer research and treatment organizations in the U.S. and one of the leading research centers for diabetes and other life-threatening illnesses. City of Hope research has been the basis for numerous breakthrough cancer medicines, as well as human synthetic insulin and monoclonal antibodies. With an independent, National Cancer Institute-designated comprehensive cancer center at its core, City of Hope brings a uniquely integrated model to patients spanning cancer care, research and development, academics and training, and innovation initiatives. City of Hope’s growing national system includes its Los Angeles campus, a network of clinical care locations across Southern California, a new cancer center in Orange County, California, and treatment facilities in Atlanta, Chicago and Phoenix. City of Hope’s affiliated group of organizations includes Translational Genomics Research Institute and AccessHope. For more information about City of Hope, follow us on Facebook, Twitter, YouTube, Instagram and LinkedIn.
Journal
Science Immunology
Article Publication Date
10-Mar-2023
