Researchers have figured out how to use a University of Buffalo (UB)-patented mucosal adjuvant, LT-IIb, to dramatically strengthen TB vaccines delivered through the mucous membranes. The discovery, which clarified that the IL-17 pathway is the best route for TB vaccines, was part of a study focused on “bacterial proteins in the type II family of bacterial heat-labile enterotoxins” (HLT), according to Terry D. Connell, PhD, UB professor of microbiology and immunology. Connell explained that LT-IIb and similar type II adjuvants can boost the body’s ability either to make antibodies or to strengthen a cellular response, depending on which type II adjuvant is selected. The research team’s next step is to understand how LT-IIb works to create IL-17 immune response. The team can then “engineer” HLT to maximize the adjuvants’ capacity to stimulate immune response. Mucosal adjuvant-based TB vaccines can be dried in powdered form and stored without refrigeration until needed. The vaccine powder then can be sterilized with boiling water, and used as a nasal spray. In contrast, most injectable vaccines must be refrigerated constantly to remain effective and safe, which is not always possible in developing countries. As drug-resistant strains of Mycobacterium tuberculosis appear, researchers are eager to find better ways to immunize people from TB, which kills more than 1.7 million people each year. Earlier TB vaccines targeted the IFN-y and T helper 1 pathways, which are still essential pathways for curing TB infections. The full report, “Interleukin-17-dependent CXCL13 Mediates Mucosal Vaccine-induced Immunity Against Tuberculosis,” was published online in the journal Mucosal Immunology (2013; doi: 10.1038/mi.2012.135).

www.aegis.org