"Backpacks" Boost Immune Cells Are Capable Of Fighting With Cancer
A group of scientists from Harvard University, led by Samir Mitragotri, created and tested microparticles on the body of mice that allow the immune system to fight tumors more effectively, according to a press release published on the University's website.
The researchers constructed a particle that was supposed to help macrophages.
These immune cells kill infected ones, but tumors can change their phenotype and "win over" them to their side. Depending on the surrounding microparticles, macrophages choose the direction of action — they either absorb pathogens (M1 phenotype) or regulate tissue growth (M2 phenotype). Tumors have factors that can switch the macrophage to the desired phenotype, which ultimately contributes to their growth and spread of metastases.
To direct macrophages to the useful anti-inflammatory M1 phenotype, scientists created a "backpack" of microparticles that clings to the cell from above with polymers. It consists of hydrophilic polyvinyl alcohol, in which interferon-gamma is dissolved. This substance switches the phenotype and has its own antitumor properties.
The cells with the "backpack" were tested on macrophage culture, as well as on mice that were transplanted with an aggressive form of breast tumor. In the first case, the introduction of microparticles led to the desired result — macrophages acquired the M1 phenotype and retained it for at least two days. Moreover, interferon-gamma contributed to the "return" of tumor-activated macrophages to the side of fighting pathogenic particles.
Experience in mice showed that the injection of particles with a "backpack" reduced the rate of tumor growth and metastasis. The authors of the study suggest that this technique will increase the effectiveness of chemotherapy and in the future will allow more targeted use of drugs.