Nanoparticles boost the potential power of a cancer vaccine

Johns Hopkins researchers have identified tiny particles that boost therapeutic cancer vaccines, which train the immune system to attack tumors. These new lipid nanoparticles (tiny structures made of fat) not only stimulate a two-pronged immune system response that improves the body’s ability to fight cancer, but also make vaccines more effective in targeting tumors.

“This research marks a crucial turning point in our understanding of how lipid nanoparticles can be harnessed to optimize anticancer immunity,” said Hai-Quan Mao, director of the Johns Hopkins Institute for Nanobiotechnology and professor in the Department of materials science from the Whiting School of Engineering. and engineering. “Our results open new avenues to improve the effectiveness of RNA-based treatments against cancer and infectious diseases.”

The team’s results appear in Natural biomedical engineering.

Lipid nanoparticles, made famous for their use in delivering messenger RNA in COVID-19 vaccines, have gained attention as carriers in cancer immunotherapy. Previous research has focused on optimizing lipid nanoparticles to trigger a strong response from T helper 1 cells, cells that enable the immune system to identify and attack cancer cells.

Using a new screening method, Mao and Yining Zhu, a biomedical engineering Ph.D. candidate and collaborator Sean C. Murphy, professor of pathology at the University of Washington, refined the composition of lipid nanoparticles to personalize and maximize activation of the immune response. They identified lipid nanoparticles that generated responses simultaneously using two parallel pathways to present tumor antigens to Th1 and Th2 cells, another type of helper cell.

The team also combined lipid nanoparticles with “checkpoint inhibitor therapy,” a type of cancer immunotherapy drug that helps the immune system recognize and attack cancer cells. These inhibitors block “checkpoints”: molecules on immune cells that stimulate or inhibit an immune response. Cancer cells sometimes escape these checkpoints and are therefore not detected by the immune system. Mao’s LNPs enhance the ability of therapeutic products to reduce tumor size and extend patient survival time.

The researchers say their study is unique because it demonstrates that lipid nanoparticles can stimulate Th1 and Th2 responses, producing coordinated attacks on cancer by multiple types of immune cells.

“This dual-attack approach represents a new breakthrough in cancer treatment,” Zhu said.