Hemolymph of triatomines presents fungistatic activity against Cryptococcus neoformans and improves macrophage function through MCP-I/TNF-α increase

Triatomines are blood-feeding arthropods belonging to the subfamily Triatominae (Hemiptera; Reduviidae), capable of producing immunomodulatory and water-soluble molecules in their hemolymph, such as antimicrobial peptides (AMPs). In this work, we evaluated the antifungal and immunomodulatory activity of the hemolymph of Meccus pallidipennis (MPH) and Rhodnius prolixus (RPH) against Cryptococcus neoformans. Methods: We assessed the activity of the hemolymph of both insects on fungal growth by a minimum inhibitory concentration (MIC) assay. Further, RAW 264.7 macrophages were cultivated with hemolymph and challenged with C. neoformans. Then, their phagocytic and killing activities were assessed. The cytokines MCP-1, IFN-γ, TNF-α, IL-10, IL-12, and IL-6 were measured in culture supernatants 4- and 48-hours post-infection. Results: Both hemolymph samples directly affected the growth rate of the fungus in a dose-dependent manner. Either MPH or RPH was capable of inhibiting fungal growth by at least 70%, using the lowest dilution (1:20). Treatment of RAW 264.7 macrophages with hemolymph of both insects was capable of increasing the production of MCP-I and TNF-α. In addition, when these cells were stimulated with hemolymph in the presence of C. neoformans, a 2- and a 4-fold increase in phagocytic rate was observed with MPH and RPH, respectively, when compared to untreated cells. For the macrophage killing activity, MPH decreased in approximately 30% the number of viable yeasts inside the cells compared to untreated control; however, treatment with RPH could not reduce the total number of viable yeasts. MPH was also capable of increasing MHC-II expression on macrophages. Regarding the cytokine production, MCP-I and TNF-α, were increased in the supernatant of macrophages treated with both hemolymphs, 4 and 48 hours after stimulation. Conclusion: These results suggested that hemolymph of triatomines may represent a source of molecules capable of presenting antifungal and immunomodulatory activity in macrophages during fungal infection.(AU)

Nuevos registros de triatominos domiciliarios y extradomiciliarios en Colombia / Colombian domiciliary and extradomiciliary triatomines

Se presenta informacion nueva sobre triatominos domiciliarios y extradomiciliarios en Colombia, que complementa los datos ya conocidos. De las 17 especies de triatominos registrados, el R. prolixus es el vector biologico mas importante de T. Cruzi y T Rangeli para el hombre por ser especie domiciliaria, muy susceptible a los tripanosomas, y poseer corto periodo defecatorio post-prandial. El T. Dimidiata y en menor grado T Maculata y T. venoso pueden tambien jugar un papel en la transmision intradomiciliaria. Las especies restantes son silvestres y responsables de las tripanosomiasis de animales. Se informa el primer registro de Panstrongylus Lignarius en Colombia. Las regiones Catatumbo Oriental -subregiones Pie de Monte, Macarena y Meta Cercano- y Valle del Rio Magdalena son las areas endemicas de T. Cruzi debido a la presencia de colonias domiciliarias de R. Prolixus. Se informa el hallazgo de R. Prolixus silvestre. La captura de adultos alados de esta especie en casas sin infeccion chagasica, sugiere falta de transmision domiciliaria