American researchers have developed a revolutionary experimental immunotherapy, based on engineered bacteria (Escherichia coli) that activate the immune response against cancer. Here’s how it works.
Thanks to genetically modified bacteria scientists have been able to attract the immune cells against some tumors and hit them, getting significant therapeutic benefits in animal models. Simply put, they have come up with a revolutionary immunotherapy experimental that could help us fight the cancer with even greater effectiveness. One of the weapons available to neoplasmsmoreover, lies precisely in the ability to evade the immune system, blocking the signals that allow its activation. But these “good,” non-pathogenic bacteria manage to infiltrate cancer cells and turn on a signal to activate immune cells, a bit like turning on a flare in an emergency.
Developing and testing GMO bacteria to activate the immune system against cancer was a research team led by scientists from the Department of Microbiology and Immunology at Columbia University in New York, who collaborated closely with colleagues from the ‘Herbert Irving Comprehensive Cancer Center and the Department of Biomedical Engineering. The scientists, coordinated by Professor Nicholas Arpaia, professor at the Vagelos College of Physicians and Surgeons of the US university, obtained the “immunotherapy bacteria” after modifying some probiotic strains Of Escherichia Colia microorganism that lives naturally in ours intestinal flora (is that occasionally it can become pathogenic).
In this study, Professor Arpaia and colleagues engineered the E. coli to go through a process of lisi (destruction) synchronized and release the desired substances, of the chemochine (proteins) that attract certain immune cells. The interesting thing about these bacteria is that they thrive inside tumors and once introduced are not detected in healthy organs. “This has been hypothesized to be due to the low pH, necrotic and immune-excluded environment…which is unique to the nucleus of a tumor and supports bacterial growth while preventing the clearing of bacteria by immune cells” , said Professor Arpaia in a press release.
Tested on mouse models (topi), these suicidal bacteria – which undergo lysis once they reach a certain concentration in the tumor – work both if inserted directly into tumor mass and if inoculated intravenously. “What we see is that the bacteria only colonize the tumor environment and only reach a certain quorum level before inducing lysis within the tumor, so we cannot detect bacteria in other healthy organs,” said Professor Arpaia.
But what substances do they release exactly? In different experiments, scientists made bacteria release two specific chemokines: the human chemokine CXCL16 (hCXCL16 K42A), which activates le cellule T able to destroy cancer cells; and chemokine CCL20 which activates the dendritic cellspeculiar branched immune cells that stimulate the immune response of B and T lymphocytes. Through the release of these substances, the bacteria stimulated the immune reaction which evaded the tumor’s natural defenses, allowing defenders to strike at the “enemy” and offer significant therapeutic benefits. The research is only in its infancy, but in the future, this strategy based on engineered good bacteria could dramatically improve theimmunotherapy against oncological diseases. The details of the research “Chemokines expressed by engineered bacteria recruit and orchestrate antitumor immunity” have been published in the scientific journal ScienceAdvances.