Leishmaniasis is a potentially fatal disease caused by a protozoal parasite transmitted through sand fly bites. There is currently no vaccine, but affected individuals are resistant to further infection, suggesting vaccination is possible. Mou et al. found that vaccination with the parasitic antigen—phosphoenolpyruvate carboxykinase (PEPCK)—protected mice against leishmaniasis. The authors identified PEPCK by examining peptides that could elicit memory T cell responses from infected and recovered but not uninfected animals. PEPCK was conserved in all pathogenic Leishmania and induced immune responses in both infected mice and human cells. Protection in mice was effective across species and was durable, supporting testing of a PEPCK-based vaccine in humans.
Z. Mou, J. Li, T. Boussoffara, H. Kishi, H. Hamana, P. Ezzati, C. Hu, W. Yi, D. Liu, F. Khadem, I. Okwor, P. Jia, K. Shitaoka, S. Wang, M. Ndao, C. Petersen, J. Chen, S. Rafati, H. Louzir, A. Muraguchi, J. A. Wilkins, J. E. Uzonna, Identification of broadly conserved cross-species protective Leishmania antigen and its responding CD4+ T cells. Sci. Transl. Med. 7, 310ra167 (2015). [Abstract]