Developing a peptide-based vaccine for Johne’s disease

Researchers are investigating the possibility of developing a peptide-based vaccine for Mycobacterium avium subspecies paratuberculosis (MAP).

Vaccinating animals with dead MAP cells can generate misleading false-positive results when vaccinated cattle are tested for bovine tuberculosis. An alternative approach could come from vaccinating the animals with specific pieces of MAP rather than using the entire bacterium, notes John Bannantine, a microbiologist with the ARS National Animal Disease Center.

Research has previously shown that a 35 kDa membrane peptide (MMP) is one of the targets of the immune response, suggesting it might be possible to develop a peptide-based vaccine based on MMP.

Bannantine and colleagues from Washington State University and Inje University in Gimhae, South Korea, used an ex vivo bacterium viability assay to evaluate the peptide’s potential as a vaccine through its ability to mobilize certain immune system cells in blood samples drawn from infected cattle.

The results, reported in the journal Vaccine, showed that the peptide helps prime cytotoxic CD8 T cells to seek out infected cells and kill MAP bacteria present within them.

Upcoming studies will focus on ways to formulate and deliver the peptide. Once there is a successful formulation, they will conduct cattle vaccine trials.

Article: Abdellrazeq, G.S., Elnaggar, M.M., Bannantine, J.P., Schneider, D.A., Souza, C.D., Hwang, J., Mahmoud, A.H.A., Hulubei, V., Fry, L.M., Park, K.T., Davis, W.C. (2019). A peptide-based vaccine for Mycobacterium avium subspecies paratuberculosis. Vaccine, 37(21):2783-2790, doi: 10.1016/j.vaccine.2019.04.040