Author(s): Cruz, Maria Geuziane Soares da
Date: 2021
Origin: Oasisbr
Subject(s): Citoader??ncia; C??lulas endoteliais; Coinfec????o por mal??ria; Hepatocarcinoma humano; Monoinfecc??o por dengue; CI??NCIAS BIOL??GICAS; Dengue; Mal??ria; Receptores endoteliais; C??lulas do hepatoma humano; Citoades??o; Co-infec????o
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FAPEAM - Funda????o de Amparo ?? Pesquisa do Estado do Amazonas
Malaria and dengue are prevalent diseases in tropical and subtropical regions and are great importance in public health. In malaria, there is a phenomenon associated with pathogenicity called cytoadherence, in which parasite sequestration occurs to other organs of the body. Some endothelial cell receptors are involved in this process such as ICAM-1, PECAM-1, VCAM-1 and P-selectin. In endemic areas to the malarial parasite and dengue virus, simultaneous infections may occur. However, little is known about malaria and dengue coinfection in Brazil. None study has yet shown what occurs in cytoadhesion during dengue-malaria coinfection. Therefore, our objective was to observe whether the adhesion of Plasmodium vivax-infected erythrocytes (PviEs) increases in human hepatocarcinoma (HEP-G2) cells concomitantly infected with dengue. Dengue 4 viral stock (DENV4) was done on C6/36 cells and PviEs were enriched by Percoll gradient to be used in the HEP-G2 cell cytoadhesion assay. Our results showed that HEP-G2 cells express the adhesion molecule ICAM-1, but not PECAM-1 and VCAM-1, while A549 cells do not express the molecules. We also showed that DENV4 replicates in HEP-G2 cells and increased ICAM-1 expression in virus-infected cells after 4 days of infection. In addition, we observed that PviEs cytoadhesion increased after DENV4 infection. Trypsin treatment, degrading parasite proteins, decreased PviEs adhesion, while the presence of anti-Pv human serum was not protective against cytoadhesion. Use of the BX795 inhibitor reduced PviEs levels, unlike chloroquine. Finally, PviEs adhesion decreased 5.5-fold in HEP-G2 cells treated with the a-ICAM-1 antibody when compared to the without blocker control. These results demonstrate that PviEs cytoadhesion increases with a concomitant DENV infection and suggest further investigations into receptors and immune pathways involved in this phenomenon during dengue-malaria coinfection. This study also alerts us to greater attention to patients diagnosed with dengue or malaria monoinfection in endemic areas.
A mal??ria e a dengue s??o doen??as prevalentes nas regi??es tropicais e subtropicais e de grande import??ncia em sa??de p??blica. Na mal??ria, existe um fen??meno associado ao aumento da patogenicidade chamado citoader??ncia, no qual ocorre o sequestro do parasita para outros ??rg??os do corpo. Alguns receptores de c??lulas endoteliais est??o envolvidos nesse processo como ICAM-1, PECAM-1, VCAM-1 e P-selectina. Em ??reas end??micas para o parasita mal??rico e o v??rus da dengue podem ocorrer infec????es simult??neas. Contudo, pouco se sabe sobre coinfec????o por mal??ria e dengue no Brasil. Nenhum estudo mostrou at?? o presente momento o que ocorre na citoades??o durante a coinfecc??o dengue-mal??ria. Por isso, nosso objetivo foi observar se a ades??o de eritr??citos infectados por Plasmodium vivax (PviEs) aumenta em c??lulas do hepatocarcinoma humano (HEP-G2) infectadas concomitantemente por dengue. O estoque viral de dengue 4 (DENV4) foi feito em c??lulas C6/36 e os PviEs foram enriquecidos por gradiente Percoll para serem usados no ensaio de citoades??o com c??lulas HEP-G2. Nossos resultados mostraram que as c??lulas HEP-G2 expressam a mol??cula de ades??o ICAM-1, mas n??o PECAM-1 e VCAM-1, enquanto as c??lulas A549 n??o expressam nenhuma destas. Mostramos tamb??m que DENV4 se replica em c??lulas HEP-G2 e houve um aumento da express??o de ICAM-1 nas c??lulas infectadas pelo v??rus, ap??s 4 dias de infec????o. Junto a isso, observamos que a citoades??o de PviEs aumentou ap??s infec????o por DENV4. O tratamento com tripsina, degradante das prote??nas do parasita, diminuiu a ades??o de PviEs, enquanto a presen??a de soro humano anti-Pv n??o preveniu a citoades??o. O uso do inibidor BX795 reduziu os n??veis de PviEs, ao contr??rio da cloroquina. Por fim, a ades??o de PviEs diminuiu 5,5 vezes em c??lulas HEP-G2 tratadas com o anticorpo a-ICAM-1, quando comparadas ao controle sem bloqueador. Esses resultados demonstram que a citoades??o de PviEs aumenta com uma infec????o concomitante por DENV e sugerem maiores investiga????es sobre receptores e vias imunes envolvidos nesse fen??meno durante a coinfec????o dengue-mal??ria. Este estudo tamb??m nos alerta para uma maior aten????o aos pacientes diagnosticados com monoinfecc??o por dengue ou mal??ria em ??reas end??micas.
