Leishmania parasites are a group of kinetoplastid pathogens that cause a variety of clinical forms while maintaining cell communication by secreting extracellular vesicles. Emerging technologies have been adapted for the studies of Leishmania-host-cell interactions to enable broad scale analysis of parasite extracellular vesicles. Leishmania extracellular vesicles (LEVS) are naturally released spheroidal nanoparticles of polydispersed suspensions surrounded by a lipid layer of membrane. Although LEVs have increasingly gained in importance, much is still unexplained, including bioavailability and function in the complex molecular mechanisms of pathogenesis. Considering the importance of LEVs in the parasite-host interaction and in the parasite-parasite relationships emerged during evolution, the current review aims at giving an overview of Leishmania summarizing knowledge and formulating guidelines for LEVs research. In the end, we report, direct methods for specific isolation of LEVs from promastigotes and amastigotes culture supernatant suitable for a range of different downstream applications increasing the compatibility and reproducibility to establish optimal and comparable isolation conditions and full LEVs characterization, and crucial immunomodulatory events triggered by this important group of parasites.

Leishmaniases are zoonotic vector-borne diseases caused by a wide variety of Leishmania species with complex transmission cycles involving different reservoirs, potential new hosts and vectors. Similarly, to other eukaryotes, Leishmania use released extracellular vesicles (LEVs) to play important initial interactions that are crucial to modulate the subsequent systemic immune response on the establishment of infection in humans and other important hosts like dogs. Recent studies in endemic areas of Brazil concluded that canine infections were predominantly due to L. amazonensis and not restricted to L. infantum (syn. Leishmania chagasi). Under these premises, the diagnosis of canine leishmaniasis needs to be improved, including the identification of current etiological agent, the clinical differential diagnosis and the histopathologic features. In this way, the dual aim of that study is to register collected observations for the diagnosis of natural canine infections and to insert in vitro results in the field of LEVs that still research gaps to be filled to understand the mechanisms and biological aspects involving the parasite-host interactions. Therefore, the future studies of Parasitology research for both of these fields are very important for the interventions for the prevention, control, elimination and eradication worldwide.

Leishmaniases are zoonotic vector-borne diseases caused by a wide variety of Leishmania species with complex transmission cycles involving different reservoirs, potential new hosts and vectors. Similarly, to other eukaryotes, Leishmania release extracellular vesicles (LEVs) to play important initial interactions that are crucial to modulate the subsequent systemic immune response on the establishment of infection in humans and others hosts like dogs. Recent studies in endemic areas of Brazil concluded that canine infections were predominantly due to L. amazonensis and not restricted to L. infantum (syn. Leishmania chagasi). Under these premises, the diagnosis of leishmaniasis needs to be improved with the identification of current etiological agent and the histopathologic features, highlighting the differential diagnosis and the molecular components of LEVs. In this way, the dual aim of that study is to register collected observations of natural canine infections, enhancing the relevance of differential diagnosis in companion animals and inserting in vitro results in the field of LEVs that still research gaps to be filled to understand the mechanisms and biological aspects involving the parasite-host interactions. Therefore, improve these studies of Parasitology research is important for diagnostic, prognostic, treatment advances and continuing need for global prevention, control, elimination/eradication of these parasitic infections.