14 DAY TRIAL // Investigators from the Massachusetts Institute of Technology (MIT) recently made an important discovery, when they are able to determine the mechanisms involved in producing larger amounts of long-term memory T cells in the immune system.
These particular cells play a critical role in underlying our bodies' immunity to infectious agents that once harmed us. After the infection is stopped, and the invading microorganisms destroyed, the memory T cells remember the confrontation.
They patrol the bloodstream, looking for tell-tale signs that the same intruders have returned. If that is the case, then the entire immune system is turned on, and the pathogens are made away with.
Problems occur when you factor in time. After a while, many memory T cells simply forget the chemical signature of the invading organisms, and therefore we lose our immunity to infections.
But the immune cells are separated in two classes – long-term and short-term. What the MIT group did was find a way of producing more long-term memory T cells, thus increasing the time span that passes between when we are infected for the first time and when we lose our immunity.
Using the new discovery, vaccine designers and drug manufacturers could create designs that would elicit long-term immunity rather than just the short version.
The investigation was conducted by MIT professor of biology Jianzhu Chen and emeritus professor of biology Herman Eisen. Chen also holds an appointment as a member of the David H. Koch Institute for Integrative Cancer Research.
The two are also senior authors of a new paper detailing the findings, which was published in this week's issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS).
According to Chen, the new findings will most likely not be used in designing the next generation of influenza vaccines. However, drugs currently under development against HIV, tuberculosis and dengue fever could make good use of the finding.
Generally, the team says, short-term T cells endure in the body for only weeks to months after the initial infections. These cells are already exhausted after battling the virus, and having to reproduce many times to fend the pathogens off.
But the battle also produces long-term T cells, which can endure for up to 70 years, as demonstrated in studies of old people who were administered the polio vaccine when they were young.
In the new research, the team demonstrated that T-cell location, the amount of antigen exposure, and length of exposure are the three main factors dictating the amount of long-term memory T cells that are produced in the body.