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Aims The aim of the study was to evaluate the immune response triggered by the first contact of human monocytes with two T cruzi strains from distinct discrete typing units (DTUs) IV and V, and whether co‐infection with these strains leads to changes in monocyte immune profiles, which could in turn influence the subsequent infection outcome. Methods and results We evaluated the influence of in vitro single‐ and co‐infection with AM64 and 3253 strains on immunological characteristics of human monocytes. Single infection of monocytes with AM64 or 3253 induced opposing anti‐inflammatory and inflammatory responses, respectively. Co‐infection was observed in over 50% of monocytes after 15 hours of culture, but this percentage dropped ten‐fold after 72 hours. Co‐infection led to high monocyte activation and an increased percentage of both IL‐10 and TNF. The decreased percentage of co‐infected cells observed after 72 hours was associated with a decreased frequency of TNF‐expressing cells. Conclusion Our results show that the exacerbated response observed in co‐infection with immune‐polarizing strains is associated with a decreased frequency of co‐infected cells, suggesting that the activated response favours parasite control. These findings may have implications for designing new Chagas disease preventive strategies.

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Continuous climate changes associated with the disorderly occupation of urban areas have exposed Latin American populations to the emergence and reemergence of arboviruses transmitted by Aedes aegypti. The magnitude of the financial and political problems these epidemics may bring to the future of developing countries is still ignored. Due to the lack of effective antiviral drugs and vaccines against arboviruses, the primary measure for preventing or reducing the transmission of diseases depends entirely on the control of vectors or the interruption of human-vector contact. In Brazil the first attempt to control A. aegypti took place in 1902 by eliminating artificial sites of eproduction. Other strategies, such as the use of oviposition traps and chemical control with dichlorodiphenyltrichlorethane and pyrethroids, were successful, but only for a limited time. More recently, biotechnical approaches, such as the release of transgenics or sterile mosquitoes and the, development of transmission blocking vaccines, are being applied to try to control the A. aegypti population and/or arbovirus transmission. Endemic countries spend about twice as much to treat patients as they do on the prevention of mosquito-transmitted diseases. The result of this strategy is an explosive outbreak of arboviruses cases. This review summarizes the social impacts caused by A. aegypti-transmitted diseases, mainly from a biotechnological perspective in vector control aimed at protecting Latin American populations against arboviruses.

Cutaneous leishmaniasis (CL) treatment is based on therapy with Glucantime , yet, there are few laboratory methods to monitor its success. In this study, ex vivo and in vitro evaluations of peripheral blood monocytes were performed in a longitudinal study to characterize the impact of Glucantime on overall phenotypic/functional features of these cells from CL patients to identify predictive biomarkers for post-therapeutic monitoring by flow cytometry. The ex vivo evaluation from CL patients demonstrated a modulatory profile before treatment, with a decrease in TLR-2, FcγRII, HLA-DR, CD86, IFN-γR, TNF, IL-12, NO, and an increase in FcγRIII and IL-10R. Conversely, treatment changes some of these biomarker expressions by decreasing FcγRIII and IL-10R and increasing IFN-γR, IL-12 and NO. Moreover, an in vitro analysis of these patients showed a reduced phagocytic capacity of Leishmania braziliensis and higher levels of IL-10 and TGF-β modulating functional profile. Regardless of the compromised L. braziliensis phagocytic capacity, treatment re-established the production of IL-12, IL-10, TGF-β and NO at the basal level. Notably, monocytes from patients with early cicatrization showed enhanced FcγRI and FcγRII expressions and reduced IL-10, which was further corroborated by a baseline fold change analysis. Finally, the logistic regression model emphasized the performance of FcγRI, FcγRII and IL-10 as robust predictive biomarkers for post-therapeutic cicatrization during cutaneous leishmaniasis.