Publicação
Unraveling the immunomodulatory potential of exosomes of cutaneous Leishmania spp. using an in vitro cellular model of skin
| Resumo: | Leishmaniasis is a neglected tropical disease caused by the protozoa Leishmania that affects millions of people yearly across the globe. Prevalence in underdeveloped countries means most people afflicted by it cannot afford proper treatment. Leishmania has evolved numerous mechanisms to avoid immune response by the host, manipulating it for its advantage. Treatment options are scarce, toxic and expensive, and vaccines for humans do not exist. Therefore, there is an urgency for novel ways to control and restrain this parasite. Exosomes are extracellular vesicles (EVs) that are generated by all cells and carry various molecules for cell communication. The present work addresses the effect of L.amazonensis and L.guyanensis EVs have on the infectivity of the parasite in the host skin, and their role as a potential prophylactic therapy. To do this, EVs were isolated from Leishmania promastigote axenic cultures and characterized. Co-cultures of human keratinocytes HaCat and human monocytic THP-1 cell lines were used to establish an in vitro simplified human skin model. The immunological response exhibited by the co-culture after stimulation with isolated parasitic EVs was analyzed by flow cytometry for several key immune markers, microscopy, spectrophotometry, and RT-qPCR of pattern recognition receptors (PRRs) and cytokines. Findings demonstrate that the model is capable of immunologic response to EVs and suggests that EVs induce a pro-inflammatory response in cells, severely impacting cell morphology and proliferation capabilities. Cytokine and PRR gene expression suggest EVs potentially to trigger a similar cellular response as contact with live parasites. Preliminary results from preexposure of THP-1 cells to EVs indicate than EVs can increase parasite infectivity, suggesting that EVS constitute an essential component of Leishmania biology. Leishmania EVs can mimic parasite presence, being recognized by innate sensors and activating the skin immune cells. Thus, Leishmania EVs can be exploited as therapeutical adjuvants for humans and animals. |
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| Autores principais: | Nakhratyan, Georgy |
| Assunto: | Cutaneous Leishmaniasis extracellular vesicles immunomodulation skin models |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | Leishmaniasis is a neglected tropical disease caused by the protozoa Leishmania that affects millions of people yearly across the globe. Prevalence in underdeveloped countries means most people afflicted by it cannot afford proper treatment. Leishmania has evolved numerous mechanisms to avoid immune response by the host, manipulating it for its advantage. Treatment options are scarce, toxic and expensive, and vaccines for humans do not exist. Therefore, there is an urgency for novel ways to control and restrain this parasite. Exosomes are extracellular vesicles (EVs) that are generated by all cells and carry various molecules for cell communication. The present work addresses the effect of L.amazonensis and L.guyanensis EVs have on the infectivity of the parasite in the host skin, and their role as a potential prophylactic therapy. To do this, EVs were isolated from Leishmania promastigote axenic cultures and characterized. Co-cultures of human keratinocytes HaCat and human monocytic THP-1 cell lines were used to establish an in vitro simplified human skin model. The immunological response exhibited by the co-culture after stimulation with isolated parasitic EVs was analyzed by flow cytometry for several key immune markers, microscopy, spectrophotometry, and RT-qPCR of pattern recognition receptors (PRRs) and cytokines. Findings demonstrate that the model is capable of immunologic response to EVs and suggests that EVs induce a pro-inflammatory response in cells, severely impacting cell morphology and proliferation capabilities. Cytokine and PRR gene expression suggest EVs potentially to trigger a similar cellular response as contact with live parasites. Preliminary results from preexposure of THP-1 cells to EVs indicate than EVs can increase parasite infectivity, suggesting that EVS constitute an essential component of Leishmania biology. Leishmania EVs can mimic parasite presence, being recognized by innate sensors and activating the skin immune cells. Thus, Leishmania EVs can be exploited as therapeutical adjuvants for humans and animals. |
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