Development of a leishmaniasis vaccine: the importance of MPL

Abstract

The parasite Leishmania has been used for pioneering work to define Tcell subsets and cytokine patterns mediating susceptibility or resistance to infectious pathogens. This understanding has been essential for the development of a new generation of candidate vaccines for major diseases, such as leishmaniases themselves, tuberculosis and others. It is clear that effective vaccines can be developed through a combination of both antigen and adjuvant selection. Until recently, no adjuvants acceptable for use in human Tcell vaccines were available. However, one such adjuvant, monophosphoryl lipid A, has been shown to be safe and effective. Just as the understanding of Tcell responses has been necessary for the development of a new generation of vaccines, an understanding of signaling by antigen-presenting cells has been essential for adjuvant selection. A combination of antigens and an adjuvant that is effective at promoting durable T-helper 1 responses and is safe for human use comprise a promising vaccine candidate, Leish-111f. This vaccine has potential application in both the prevention and treatment of leishmaniasis.