Researchers at Johns Hopkins have succeeded in making flattened, football-shaped artificial particles that impersonate immune cells. These football-shaped particles seem to be better than the typical basketball-shaped particles at teaching immune cells to recognize and destroy cancer cells in mice.
"The shape of the particles really seems to matter because the stretched, ellipsoidal particles we made performed much better than spherical ones in activating the immune system and reducing the animals' tumors," according to Jordan Green, Ph.D., assistant professor of biomedical engineering at the Johns Hopkins University School of Medicine and a collaborator on this work. A summary of the team's results was published online in the journal Biomaterials on Oct. 5.
According to Green, one of the greatest challenges in the field of cancer medicine is tracking down and killing tumor cells once they have metastasized and escaped from a tumor mass. One strategy has been to create tiny artificial capsules that stealthily carry toxic drugs throughout the body so that they can reach the escaped tumor cells. "Unfortunately, traditional chemotherapy drugs do not know healthy cells from tumor cells, but immune system cells recognize this difference. We wanted to enhance the natural ability of T-cells to find and attack tumor cells," says Jonathan Schneck, M.D., Ph.D., professor of pathology, medicine and oncology.
In their experiments, Schneck and Green's interdisciplinary team exploited the well-known immune system interaction between antigen-presenting cells (APC) and T-cells. APCs "swallow" invaders and then display on their surfaces chewed-up protein pieces from the invaders along with molecular "danger signals." When circulating T-cells interact with APCs, they learn that those proteins come from an enemy, so that if the T-cells see those proteins again, they divide rapidly to create an army that attacks and kills the invaders.
|Contact: Catherine Kolf|
Johns Hopkins Medicine