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)

Evaluación de un Bioinsecticida Formulado con Metarhizium anisopliae y Beauveria bassiana (balsamo) Vuillemin para el control biológico de Meccus pallidipennis vector de la enfermedad de Chagas / Evaluation of a Bioinsecticide Formulated with Metarhizium anisopliae and Beauveria bassiana (balsam) Vuillemin for the biological control of Meccus pallidipennis vector of Chagas disease

La Tripanosomiasis americana, también conocida como enfermedad de Chagas, es un padecimiento potencialmente mortal cuyo agente etiológico es el parásito protozoo Trypanosoma cruzi (Chagas 1909 Kinestoplastida: Trypanosomatidae). A pesar de contar con una amplia evidencia clínica se desconocen las cifras de prevalencia en el país ya que para el sistema de salud público mexicano en este momento dicha enfermedad no constituye una prioridad. La existencia de al menos 33 especies de vectores y con elevados índices de infección natural redunda en la aparición de casos positivos que llegan a incluir niños, lo que demuestra una vía activa de transmisión y da fortalezas a criterios de endemicidad. La transmisión del parásito que produce la enfermedad se da a través de varias vías pero en el 33% de los casos se ha reconocido que es por vía vectorial, de allí que el éxito de las campañas de control de los insectos permitirá la disminución drástica del número de infectados. Los métodos de control químico han sido inefectivos debido a problemas operacionales en las campañas y a la falta de integración entre estos, así como a la resistencia de los insectos a los productos.