Designer Bacteria May Lead to Better Vaccines
Date: 22.1.2013
Researchers at The University of Texas at Austin have developed a menu of 61 new strains of genetically engineered bacteria that may improve the efficacy of vaccines for diseases such as flu, pertussis, cholera and HPV.
The strains of E. coli, which were described in a paper published this month in the journal PNAS, are part of a new class of biological "adjuvants" that is poised to transform vaccine design. Adjuvants are substances added to vaccines to boost the human immune response.
In 2009, the FDA approved a new vaccine for human papillomavirus (HPV). It included a new kind of adjuvant that's a modified version of an endotoxin molecule.
These molecules, which can be dangerous, appear on the cell surface of a wide range of bacteria. As a result, humans have evolved over millions of years to detect and respond to them quickly. They trigger an immediate red alert.
What Trent and his colleagues have done is expand on that basic premise. Rather than just work with an inert piece of endotoxin, they've engineered E. coli bacteria to express the endotoxin in many configurations on the cell surface.
"These 61 E. coli strains each have a different profile on their surface," said Brittany Needham, a doctoral student in Trent's lab and the first author on the paper. "In every case the surface structure of the endotoxin is safe, but it will interact with the immune system in a range of ways. Suddenly we have a huge potential menu of adjuvants to test out with different kinds of vaccines."
