Cross‐protective efficacy from a immunogen firstly identified in Leishmania infantum against tegumentary leishmaniasis

Abstract

Experimental vaccine candidates have been evaluated to prevent leishmaniasis, but no commercial vaccine has been proved to be effective against more than one parasite species. LiHyT is a Leishmania-specific protein that was firstly identified as protective against Leishmania infantum. In this study, LiHyT was evaluated as a vaccine to against two Leishmania species causing tegumentary leishmaniasis (TL): Leishmania major and Leishmania braziliensis. BALB/c mice were immunized with rLiHyT plus saponin and lately challenged with promastigotes of the two parasite species. The immune response generated was evaluated before and 10 weeks after infection, as well as the parasite burden at this time after infection. The vaccination induced a Th1 response, which was characterized by the production of IFN-γ, IL-12 and GM-CSF, as well as by high levels of IgG2a antibodies, after in vitro stimulation using both the protein and parasite extracts. After challenge, vaccinated mice showed significant reductions in their infected footpads, as well as in the parasite burden in the tissue and organs evaluated, when compared to the control groups. The anti-Leishmania Th1 response was maintained after infection, being the IFN-γ production based mainly on CD4(+) T cells. We described one conserved Leishmania-specific protein that could compose a pan-Leishmania vaccine.

Arginase activity of Leishmania isolated from patients with cutaneous leishmaniasis

“…The disease is categorized as cutaneous (CL), mucocutaneous (MCL) and visceral leishmaniasis (VL), which is caused by over 20 species of the Leishmania (L) parasites . Cutaneous leishmaniasis (CL) with an estimated incidence of 1.5‐2 million cases annually is the most prevalent form of leishmaniasis . Although it is an endemic disease in 98 countries, approximately 75% of human CL cases are reported in only 10 countries including Afghanistan, Algeria, Brazil, Colombia, Costa Rica, Ethiopia, Iran, Sudan, Peru and Syria …”

Production of a kinesin-related recombinant protein (Lbk39) from Leishmania braziliensis by Leishmania tarentolae promastigotes and its application in the serodiagnosis of leishmaniasis

“…It is also known that antibodies are produced through neutrophil stimulation at the very beginning of the infection. Although various studies suggest that such antibodies play no role in host protection, they can be useful in diagnosis for determining the presence of the parasite [1,26].…”