A colorized scanning electron micrograph of a human natural killer cell. NIAID
Natural killer cells come by their moniker honestly. They are a type of immune cell with particularly potent powers. Unlike other types of immune cells, NK cells have the ability to recognize and kill stressed cells without first detecting antibodies or the major histocompatibility complex that signal an infection. They do not have to be activated. They can begin killing target cells within hours. They can engage with multiple targets simultaneously. They secrete large amounts of antiviral cytokines and chemokines – proteins that help boost immune response.
That makes NK cells an especially attractive therapeutic weapon against numerous viral menaces: HIV, influenza, cytomegalovirus (CMV) and SARS-Cov-2 among them. In a new review, published January 4, 2023 in the journal Science Translational Medicine, lead author Davey M. Smith, MD, head of Infectious Diseases and Global Public Health at UC San Diego School of Medicine and an infectious disease specialist at UC San Diego Health, and colleagues discuss current (and incomplete) knowledge of NK cell roles and speculate how they might be leveraged against multiple viral scourges.
“NK cell therapy may represent a new class of antiviral treatment, which is perhaps most promising for incurable viral infections, such as HIV and CMV, and persistent viral infections in immunocompromised persons, such as SARS-CoV-2 and influenza virus,” the authors write.
“Advantages of NK cell–based therapy include new options for persons with multidrug-resistant infections or persons who cannot tolerate other available therapies. It is also unlikely that viral drug resistance, as seen with HIV and influenza virus in response to antiviral drugs, will develop with NK cell–based therapies.”
Others are looking at how “super” natural killer cells might be used to treat some forms of cancer. For example, Dan Kaufman, MD, PhD, professor of medicine in the Division of Regenerative Medicine, director of cell therapy at UC San Diego School of Medicine and a faculty member of both the Sanford Consortium for Regenerative Medicine and the Sanford Stem Cell Clinical Center at UC San Diego Health, and colleagues have created NK cells with boosted anti-tumor activity by using modified stem cells. The researchers are now seeking to develop a clinical therapy.
— Scott LaFee