Microbiologists discover new pathway for mucosal TB vaccine

Microbiologists at the University of Buffalo recently discovered a novel pathway for tuberculosis vaccines as part of a collaboration with researchers from multiple universities.

Shabaana A. Khader, the lead author on the study, Terry D. Connell, the study's co-author, and their team used LT-IIb, a novel, mucosal adjuvant, to identify the pathway in animal studies. The team showed that LT-IIb increases the potency of vaccines administered to mucous membranes.

"This research demonstrates that the most effective vaccination against TB should target the IL-17 pathway," Connell, a professor of microbiology at the University of Buffalo's School of Medicine and Biomedical Sciences, said. "This observation is in stark contrast to the importance of the IFN-Y and T helper 1 pathways in combating TB infection in the body, which have been the traditional targets for TB vaccines."

Connell said that while the traditional pathways used for combating TB infection are needed to overcome the disease, the study demonstrates that the IL-17 pathway is more important for eliciting immune protection.

Connell's lab is a leader in the study of LT-IIb and similar adjuvants from the type II family of bacterial heat-labile enterotoxins.

"The adjuvants, which UB patented in 2008 have some unique characteristics," Connell said. "Depending on the type of adjuvant, one can either enhance the body's ability to make antibodies or enhance the body's cytotoxic response. The great benefit of our type II HLT adjuvants is that these molecules can activate both pathways. We can direct the type of immune response to the vaccine that is desired, whether an antibody response or a cellular response, simply by choosing one or the other type II adjuvant."

Connell said that one benefit of mucosal vaccines is that they could be administered by some other route than injection. This would avoid the costly cold chain that is needed to preserve most injectable vaccines.

Connell said the next step for the collaborative research project would be the identification of the cellular and molecular mechanisms used by LT-IIb to induce IL-17 immune responses.

The study was published in Mucosal Immunology, a journal published by the Nature group.