BackgroundThe main control strategy for visceral leishmaniasis in Brazil has been based on the elimination of seropositive dogs, although this is not widely accepted. In this context, the use of a long-lasting protective vaccine against canine visceral leishmaniasis (CVL) has been highly expected. The aim of this work was to determine the timeline kinetics of the cytokine microenvironment derived from circulating leukocytes as supportive immunological biomarkers triggered by Leishmune® vaccine. Cross-sectional kinetic analysis of cellular immunity cytokines was carried out at three times (1, 6 and 12 months) after primovaccination with Leishmune®. In vitro short-term whole blood cultures were stimulated with Leishmania infantum soluble antigen (SLAg). The secreted cytokine signatures and their major sources were determined.ResultsAt six months after vaccination, Leishmune® induced an increase in IL-8, IFN-γ, IL-17a and TNF-α levels and a decrease in IL-10. Cytokine signature analysis revealed a shift in the microenvironment towards a pro-inflammatory profile mediated by IL-8 and IFN-γ. Both, CD4+ (↑TNF-α+ and ↑IFN-γ +) and CD8+ (↑IL-17a and ↓IL-4) T-cells contributed to the acquired immune responses observed after stimulation with SLAg.ConclusionsThe changes observed in the cytokine profile suggested that Leishmune® was able to induce an effective response at six months after primovaccination. After one year, it returned to baseline suggesting the need of additional boosting.
In this study, strategies for serum biomarker assessment were developed for therapeutic monitoring of HCV patients. For this purpose, serum chemokine/cytokine levels were measured by cytometric-bead-array in HCV patients, categorized according to immunotherapy response as: non-responder/NR, relapser/REL and sustained-virologic-responder/SVR. The results demonstrated an overall increase of serum chemokine/cytokine levels in HCV patients. In general, therapeutic failure was associated with presence of a predominant baseline proinflammatory pattern with enhanced CCL5/RANTES, IFN-α, IFN-γ along with decreased IL-10 levels in NR and increased IL-6 and TNF in REL. SVR displayed lower baseline proinflammatory status with decreased CXCL8/IL-8, IL-12 and IL-17 levels. The inability to uphold IFN-α levels during immunotherapy was characteristic of NR. Serum chemokine/cytokine signatures further support the deleterious effect of proinflammatory baseline status and the critical role of increased/persistent IFN-α levels to guarantee the sustained virologic response. The prominent baseline proinflammatory milieu observed in NR and REL yielded a restricted biomarker network with small number of neighborhood connections, whereas SVR displayed a network with integrated cytokine connectivity. Noteworthy was that SVR presented a shift towards a proinflammatory pattern upon immunotherapy, assuming a pattern similar to that observed in NR and REL at baseline. Moreover, the immunotherapy guided REL towards a profile similar to SVR at baseline. Analysis of baseline-fold changes during treatment pointed out IFN-α and TNF as high-performance biomarkers to monitor immunotherapy outcome. This knowledge may contribute for novel insights into the treatment and control of the continuous public health threat posed by HCV infection worldwide.
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