Structuring the components of vaccines, rather than blending them into a mixture, may transform the way cancers are treated and infections are prevented, studies in mice suggest.
Vaccines often have two components, a replica of an "invader" the immune system must learn to recognize known as an antigen - this can be a part of a cancer cell, or a piece of a virus or bacterium - and something to strengthen the immune system's response, known as an adjuvant.
Conventionally, antigens and adjuvants are blended together, and it's impossible to predict how much of each component will reach each immune cell.
"The blended mish-mosh works to some extent," but effectiveness can be improved by organizing vaccine components in specific ways, said Chad Mirkin, director of the International Institute for Nanotechnology at Northwestern University and co-founder of biotech startup Flashpoint Therapeutics.
The spherical nanostructure platform his team invented allows for delivery of precise doses of antigen and adjuvant to every immune cell, so they are all equally primed to attack the invader. Researchers can change the structural locations of the components until they find the most effective organization – an approach Mirkin calls "rational vaccinology."
In experiments in mice funded by Northwestern and by the National Cancer Institute and described on Monday in Nature Biomedical Engineering, his team compared two cancer vaccines with the same ingredients but with different structures.
One of the vaccines yielded much slower tumor growth and much longer survival than the other.
Mirkin's team has observed improved effectiveness with structured vaccines in mice with triple-negative breast cancer, papillomavirus-induced cervical cancer, melanoma, colon cancer, prostate cancer, and certain other tumors, he said.
They have seen similar effects in experimental vaccines against infectious organisms, he said.
"We can't tell you that this approach will always lead to curative vaccines, but we can tell you it will lead to better vaccines," Mirkin said.
More research is needed before the vaccines can be tested in humans.
Read more about cancer vaccines on Reuters.com
