The impact of Leishmania infection on the migratory behaviour of host macrophages

• Autor(a) principal: Castro, Mafalda Sofia Mendonça de
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/41054
• topic: Leishmania; Macrophages; Migration; PI3K/AKT/RTK pathway; Migration inhibitors

Leishmaniasis, a prevalent neglected tropical disease, impacts millions of people worldwide and is transmitted through the bite of a sandfly infected with Leishmania parasites. While treatments for Leishmaniasis exist, they are not Leishmania-specific, are often associated with significant side effects, and remain inaccessible in many endemic regions. The disease presents a range of clinical forms, spanning from cutaneous lesions to severe visceral infections. Leishmania species are linked to distinct disease tropisms, but the precise mechanisms responsible for these variations remains unknown. Research suggests that macrophages play a pivotal role in the disease's dissemination. To study Leishmania's impact on macrophage migration, it is crucial to have good infection rates stablished. We explored both parasite enrichment and detection methods. Neither the PNA nor Ficoll-based techniques significantly improved infection rates in our in vitro model. Instead, pre-labelling promastigotes with CFSE proved a reliable infection detection method. To study the macrophages migration patterns, different cell migration assays were employed. Wound healing assays revealed inconsistencies attributed to limitations within the assay model. Alternatively, a stimuli-free random cell migration assays enabled precise tracking of individual macrophages. Nevertheless, this method also showed no consistent patterns in the macrophage’s migration dependent of Leishmania infection. Moreover, Dasatinib and Wortmannin, known inhibitors of migration in other cell types, were also tested for their effect on macrophages, an aspect that had not been previously explored beyond our research group. However, they exhibited no significant effects in our assays. Differences in cell type and assay design may account for these inconsistencies. Analysis of cell morphology suggested that macrophage polarization could influence migration patterns and further investigation is required to understand the underlying mechanisms. In conclusion, this research underscores the complexities of Leishmania-macrophage interactions and emphasizes the need for further studies to elucidate the intricate host-parasite dynamics in the context of Leishmaniasis and macrophage biology.