Camel nanobodies: Promising molecular tools against leishmaniasis

Abstract

AimTo characterize several anti‐Leishmania tropica nanobodies and to investigate their effect on Leishmania infection.MethodsSeveral immunological tests were implied to characterize five different (as confirmed by sequencing) anti‐L tropica nanobodies (NbLt05, NbLt06, NbLt14, NbLt24 and NbLt36) against parasite lysates or intact cells from different stages, promastigotes and amastigotes. Direct inhibitory effect of these nanobodies on parasite infection cycle on macrophages was tested in cell culture.ResultsAll the five nanobodies (with distinguished characteristics) were more specific to L tropica than to L major, but could equally recognize the lysate and the outer surface of the intact cells from the two main stages of the parasite. Nanobodies recognized several leishmania antigens (majorly between 75 and 63 kDa), and their proteinaceous nature was confirmed. Because of its role in leishmania life cycle, gp63 was considered a potential antigen candidate for nanobodies, and bioinformatics predicted such interaction. All nanobodies have a negative effect on the infectivity of L tropica, as they decreased the number of infected macrophages and the amastigotes inside those macrophages.ConclusionSuch anti‐leishmania nanobodies, with outstanding characteristics and important target, can be of great use in the development of promising treatment strategies against leishmaniasis.