This work aims at identifying an effective protocol to raise anti-Leishmania chagasi amastigote antibodies in different animal species. Protocols of immunization by subcutaneous injections of L. chagasi promastigote and amastigote lysates or by either intravenous or subcutaneous inoculation of live metacyclic promastigotes were assessed in mice, rabbits, and dogs. The immunization with live pro...

The parasitic protozoan Leishmania alternates between an invertebrate and a mammalian host. Upon their entry to mammalian macrophages, Leishmania promastigotes differentiate into amastigote forms within the harsh environment of the phagolysosomal compartment. Here, we provide evidence for the importance of translational control during the Leishmania differentiation process. We find that exposur...

The role of glycosphingolipids (GSLs) present in amastigote forms of Leishmania (Leishmania) amazonensis during infection of macrophages was analyzed, with particular emphasis on GSLs presenting the terminal Galpss1-3Galpa disaccharide. Macrophage invasion by L. (L.) amazonensis amastigotes was reduced by 37% when the disaccharide Galpss1-3Galp (1 mM) was added to the culture medium. The putati...

Protozoa and bacteria infect various types of phagocytic cells including macrophages, monocytes, dendritic cells and eosinophils. However, it is not clear which of these cells process and present microbial antigens in vivo and in which cellular compartments parasite peptides are loaded onto Major Histocompatibility Complex molecules. To address these issues, we have infected susceptible BALB/c ...

it is well accepted that in experimental model of leishmania major infection, balb/c mice mount a th2 response and produce igg1 predominantly whereas c57bl/6mice enhance th1 response with the biased production of igg2a antibodies. therefore, screening for parasite antigens on the basis of reactivity with sera from infected susceptible or resistant mice might be used for the identification of th...

A new method is described which has made possible the long-term axenic cultivation of Leishmania mexicana amastigote-like forms in Schneider's Drosophila medium supplemented with 20% (v/v) foetal calf serum. Unlike previous methods, it utilizes direct culture of parasites obtained from the lesions of infected animals rather than adaptation of promastigotes in vitro. Ultrastructural (possession ...

OBJECTIVES To evaluate the in vitro leishmanicidal activity of nine flavonoid derivatives from Delphinium staphisagria against L. infantum and L. braziliensis. DESIGN AND METHODS The in vitro activity of compounds 1-9 was assayed on extracellular promastigote and axenic amastigote forms and on intracellular amastigote forms of the parasites. Infectivity and cytotoxicity tests were carried on ...

BACKGROUND Leishmaniasis is an antropozoonosis caused by Leishmania parasites that affects around 12 million people in 98 different countries. The disease has different clinical forms, which depend mainly on the parasite genetics and on the immunologic status of the host. The promastigote form of the parasite is transmitted by an infected female phlebotomine sand fly, is internalized by phagocy...

Laboratory mice display features of bona fide hosts for parasites such as Leishmania major and Leishmania donovani. Characterizing the amastigote population size fluctuations and the mouse transcript abundance accounting for these fluctuations demands the capacity to record in real time and integrate quantitative multiparametric datasets from the host tissues where these processes occur. To thi...

Leishmaniasis is a tropical disease threatening 350 million people from endemic regions. The available drugs for treatment are inadequate, with limitations such as serious side effects, parasite resistance or high cost. Driven by this need for new drugs, we developed a high-content, high-throughput image-based screening assay targeting the intracellular amastigote stage of different species of ...