Researchers from UT Southwestern Medical Center, Dallas, have developed a first-of-its-kind nanoparticle vaccine immunotherapy that targets several different cancer types. The nanovaccine consists of tumor antigens inside a synthetic polymer nanoparticle.
"What is unique about our design is the simplicity of the single-polymer composition that can precisely deliver tumor antigens to immune cells while stimulating innate immunity. These actions result in safe and robust production of tumor-specific T cells that kill cancer cells," said Jinming Gao, PhD, Professor of Pharmacology and Otolaryngology in UT Southwestern's Harold C. Simmons Comprehensive Cancer Center.
A study outlining this research reported the nanovaccine had anti-tumor efficacy in multiple tumor types in mice (Nature Nanotechnology 2017; doi:10.1038/nnano.2017.52). The research was a collaboration between the laboratories of study senior authors Gao and Zhijian "James" Chen, PhD, Professor of Molecular Biology and Director of the Center for Inflammation Research.
Typical vaccines require immune cells to pick up tumor antigens in a "depot system" and then travel to the lymphoid organs for T-cell activation, Gao said. Instead, nanoparticle vaccines can travel directly to the body's lymph nodes to activate tumor-specific immune responses.
"For nanoparticle vaccines to work, they must deliver antigens to proper cellular compartments within specialized immune cells called antigen-presenting cells and stimulate innate immunity," explained Chen. "Our nanovaccine did all of those things."
In this case, the experimental UTSW nanovaccine works by activating an adaptor protein called STING, which stimulates the body's immune defense system to ward off cancer.
The scientists examined a variety of tumor models in mice: melanoma, colorectal cancer, and HPV-related cancers of the cervix, head, neck, and anogenital regions. In most cases, the nanovaccine slowed tumor growth and extended the animals' lives. The team is now working with physicians at UT Southwestern to explore clinical testing of the STING-activating nanovaccines for a variety of cancer indications. Combining nanovaccines with radiation or other immunotherapy strategies can augment anti-tumor effectiveness.