When the body encounters a new pathogen such as a virus or microbe it generates cells called memory B lymphocytes to create a tailor-made response to that pathogen.
By Donna Rachel Edmunds, World Israel News
Israeli scientists may have figured out a way to keep our immune systems young even as we grow old, potentially eliminating the vulnerability that elderly people have to new diseases.
It is commonly understood that elderly people have a particularly hard time in fighting off new pathogens in the population, making new strains of common illnesses such as cold and flu more dangerous for us to encounter as we grow older.
Now, scientists working at Technion, the Israel Institute of Technology, have figured out why that happens, and what can be done about it.
When the body encounters a new pathogen such as a virus or microbe it generates cells called memory B lymphocytes to create a tailor-made response to that pathogen. Their job is to recognize that same pathogen the next time it is encountered, and to deploy antibodies capable of more swiftly countering the threat.
It is this mechanism that vaccines are designed to provoke, by giving the body something that it can create a specified immune response against.
And while it has been known for some time that older people are less effective at creating memory B lymphocytes, scientists were not sure why until now. It was this question that Reem Dowery was able to answer for her doctoral thesis, working under the guidance of Prof. Doron Melamed of the Technion’s Ruth and Bruce Rappaport Faculty of Medicine and his team. Their findings were recently published in the journal Blood.
It turns out that the memory B lymphocytes responsible for immune memory give out hormonal signals to bone marrow cells responsible for new cell production, which impede the creation of new cells. In effect, the body ‘fills up’ with B lymphocytes leaving no room for new ones.
The result is that the older we get, the less we are able to produce new memory cells, causing our immune response to new illnesses to fade over time.
Having discovered the mechanism that caused the problem, the researchers wondered whether it might be possible to counter it. To answer that question, the researchers joined forces with the departments of hematology and rheumatology at the Sourasky Medical Center and the Rambam Health Care Campus, respectively.
One of the treatments for certain medical conditions, such as lupus, lymphoma and multiple sclerosis, is to remove a significant number of memory B lymphocytes from the patient’s body. The result, the research team found, was that these patients were able to produce new, highly potent B lymphocytes once more.
In effect, by clearing space by removing the older B lymphocytes, the body’s immune system had been rejuvenated, allowing it to work more effectively again.
Another potential route to rejuvenating the immune system identified by the researchers was to inhibit one of the hormones involved in suppressing new memory B lymphocytes from being produced by the bone marrow, something that Reem Dowery and Prof. Melamed showed to be possible in their proof-of-concept study.
Not only are the findings a breakthrough in scientific terms, but they mean that future generations could have their immune system kept in tip-top condition throughout their entire life, ending the vulnerability of elderly people to new diseases.