Researchers in Japan have developed a new vaccine that they argue could remove senescent cells, also known as zombie cells, which are usually associated with aging and several diseases. Mice administrated with the vaccine showed decreased levels of the zombie cells, creating antibodies that attach to the cells and removing them. 

Professor Toru Minamino of Juntendo University and a team of researchers identified a protein in senescent cells in humans and mice, then created a peptide vaccine that targets it. When applied, the body creates antibodies that attach themselves to the cells, which are then removed by white blood cells that adhere to these antibodies, Minamino told The Japan Times.

The researchers first administered the new vaccine to mice with arterial stiffness, reporting positive results. Plenty of accumulate zombie cells were removed and areas affected by the disease were reduced. Then they applied the vaccine in older mice, in which the progression of age proved to be slower compared to mice who hadn’t been vaccinated. 

“Senolytic vaccination also improved normal and pathological phenotypes associated with aging, and extended the male lifespan of progeroid mice,” the researchers wrote in their paper in the journal Nature Aging, reporting on the results. “Our results suggest that vaccination targeting seno-antigens could be a potential strategy for new senolytic therapies.”

Understanding zombie cells

A wide array of stress factors can harm our body cells. Ideally, these are removed through our immune system through a process called apoptosis. But as we get older the body isn’t as effective at removing dysfunctional cells. This can contribute to an already weakened immune system and less efficient biological processes, triggering disease. 

Over the years, researchers have been exploring whether better management of senescence cells can revitalize aging tissues and increase active years of life. These cells are quite unique as they eventually stop multiplying but don’t die when they should. Instead, they continue releasing chemicals that can cause inflammation – like a moldy fruit affecting the rest. 

The older we are, the more zombie cells we have in our body. And since our immune system is less efficient, these cells accumulate and affect healthy ones. This can affect our ability to cope with illness or stress, recuperate from injuries and even learn new things, like another language – as zombie cells also degrade our brain’s cognitive functions. 

Senescent cells have been linked with a set of age-related conditions, such as cancer, stroke, Alzheimer’s disease, diabetes, cardiovascular disease and even eyesight problems. Researchers have been looking at these cells since early 1960s, with investigations currently being done on a potential connection with cytokine storm induced by Covid-19. 

Back in May, researchers at the University of California, San Francisco (UCSF) reported having discovered how immune cells naturally clear the body of zombie cells. Their finding, based on laboratory experiments in mice, could open the door to new approaches and strategies to treat age-related diseased with immunotherapy, they argued. 

The study behind the new vaccine was published in the journal Nature Aging.