RESUMO
Leishmania (Viannia) guyanensis is a causal agent of American tegumentary leishmaniasis (ATL). This protozoan has been poorly investigated; however, it can cause different clinical forms of ATL, ranging from a single cutaneous lesion to severe lesions that can lead to destruction of the nasopharyngeal mucosa. L. (V.) guyanensis and the disease caused by this species can present unique aspects revealing the need to better characterize this parasite species to improve our knowledge of the immunopathological mechanisms and treatment options for ATL. The mechanisms by which some patients develop a more severe form of ATL remain unclear. It is known that the host immune profile and parasite factors may influence the clinical manifestations of the disease. Besides intrinsic parasite factors, Leishmaniavirus RNA 1 (LRV1) infecting L. guyanensis can contribute to ATL immunopathogenesis. In this review, general aspects of L. guyanensis infection in humans and mouse models are presented.
Assuntos
Interações Hospedeiro-Parasita/imunologia , Leishmania guyanensis/patogenicidade , Leishmaniose Cutânea/patologia , Leishmaniavirus/patogenicidade , Mucosa/patologia , Animais , Modelos Animais de Doenças , Humanos , Imunidade Inata , Interleucina-17/biossíntese , Interleucina-17/imunologia , Leishmania guyanensis/imunologia , Leishmania guyanensis/virologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Leishmaniavirus/fisiologia , Camundongos , Mucosa/imunologia , Mucosa/parasitologia , Nasofaringe/imunologia , Nasofaringe/parasitologia , Nasofaringe/patologia , Índice de Gravidade de DoençaRESUMO
Viruses of trypanosomatids are now being extensively studied because of their diversity and the roles they play in flagellates' biology. Among the most prominent examples are leishmaniaviruses implicated in pathogenesis of Leishmania parasites. Here, we present a historical overview of this field, starting with early reports of virus-like particles on electron microphotographs, and culminating in detailed molecular descriptions of viruses obtained using modern next generation sequencing-based techniques. Because of their diversity, different life cycle strategies and host specificity, we believe that trypanosomatids are a fertile ground for further explorations to better understand viral evolution, routes of transitions, and molecular mechanisms of adaptation to different hosts.
Assuntos
Vírus de RNA/fisiologia , Trypanosomatina/virologia , Animais , Especificidade de Hospedeiro , Leishmaniavirus/fisiologia , Microscopia Eletrônica de TransmissãoRESUMO
Viruses of trypanosomatids are now being extensively studied because of their diversity and the roles they play in flagellates' biology. Among the most prominent examples are leishmaniaviruses implicated in pathogenesis of Leishmania parasites. Here, we present a historical overview of this field, starting with early reports of virus-like particles on electron microphotographs, and culminating in detailed molecular descriptions of viruses obtained using modern next generation sequencing-based techniques. Because of their diversity, different life cycle strategies and host specificity, we believe that trypanosomatids are a fertile ground for further explorations to better understand viral evolution, routes of transitions, and molecular mechanisms of adaptation to different hosts.
Assuntos
Vírus de RNA , Trypanosomatina/virologia , Microscopia Eletrônica de Transmissão e Varredura , Leishmaniavirus/fisiologia , Especificidade de HospedeiroRESUMO
Leishmaniavirus is a double-stranded RNA virus that persistently infects some strains of the protozoan parasite Leishmania. There is considerable interest in the possibility that the presence of this virus alters parasite phenotype and may affect disease pathogenesis. If so, the virus marker could provide a valuable prognostic indicator for human leishmaniasis, particularly in those cases caused by New World parasite strains. The virus has been detected in cultured L. braziliensis, L. b. guyanensis, and L. major. To date there has been no information as to the extent of infection in samples prior to culturing in the laboratory. This study demonstrates, through the reverse transcription-polymerase chain reaction, that Leishmaniavirus exists in human biopsy samples of leishmaniasis prior to manipulation in culture.