Transplantation of Engineered Macrophages Rescues Mice from Sepsis

In this study, researchers collected monocytes from the bone marrow of healthy mice and cultured them in conditions that transformed them into macrophages. The lab also developed vitamin-based nanoparticles that were especially good at delivering messenger RNA, molecules that translate genetic information into functional proteins.

The scientists, who specialize in messenger RNA for therapeutic purposes, constructed a messenger RNA encoding an antimicrobial peptide and a signal protein. The signal protein enabled the specific accumulation of the antimicrobial peptide in internal macrophage structures called lysosomes, the key location for bacteria-killing activities. From here, researchers delivered the nanoparticles loaded with that messenger RNA into the macrophages they had produced with donor monocytes, and let the cells take it from there to "manufacture" a new therapy.

After seeing promising results in cell tests, the researchers administered the cell therapy to mice. The mouse models of sepsis in this study were infected with multidrug-resistant Staphylococcus aureus and E. coli and their immune systems were suppressed. Each treatment consisted of about 4 million engineered macrophages. Controls for comparison included ordinary macrophages and a placebo. Compared to controls, the treatment resulted in a significant reduction in bacteria in the blood after 24 hours - and for those with lingering bacteria in the blood, a second treatment cleared them away.
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Source: Fight Aging! - January 13, 2020 Category: Research Authors: Reason Tags: Medicine, Biotech, Research Source Type: blogs