Innate immune receptors are differentially expressed in mice during experimental Schistosoma mansoni early infection.

BACKGROUND: The impact of Schistosoma mansoni infection over the immune response and the mechanisms involved in pathogenesis are not yet completely understood. OBJECTIVES: This study aimed to evaluate the expression of innate immune receptors in three distinct mouse lineages (BALB/c, C57BL/6 and Swiss) during experimental S. mansoni infection with LE strain. METHODS: The parasite burden, intestinal tissue oogram and presence of hepatic granulomas were evaluated at 7- and 12-weeks post infection (wpi). The mRNA expression for innate Toll-like receptors, Nod-like receptors, their adaptor molecules, and cytokines were determined at 2, 7 and 12 wpi in the hepatic tissue by real-time quantitative polymerase chain reaction (qPCR). FINDINGS: Swiss mice showed 100% of survival, had lower parasite burden and intestinal eggs, while infected BALB/c and C57BL/6 presented 80% and 90% of survival, respectively, higher parasite burden and intestinal eggs. The three mouse lineages displayed distinct patterns in the expression of innate immune receptors, their adaptor molecules and cytokines, at 2 and 7 wpi. MAIN CONCLUSIONS: Our results suggest that the pathogenesis of S. mansoni infection is related to a dynamic early activation of innate immunity receptors and cytokines important for the control of developing worms.

Insecticidal activity of fluralaner (Exzolt®) administered to Gallus gallus domesticus against triatomines (Hemiptera, Reduviidae, Triatominae).

BACKGROUND: Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata and Rhodnius prolixus are vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Chickens serve as an important blood food source for triatomines. This study aimed to assess the insecticidal activity of fluralaner (Exzolt®) administered to chickens against triatomines (R. prolixus, T. infestans, T. brasiliensis and T. pseudomaculata). METHODS: Twelve non-breed chickens (Gallus gallus domesticus) were randomized based on weight into three groups: negative control (n = 4); a single dose of 0.5 mg/kg fluralaner (Exzolt®) (n = 4); two doses of 0.5 mg/kg fluralaner (Exzolt®) (n = 4). Nymphs of 3rd, 4th and 5th instars of R. prolixus, T. infestans, T. brasiliensis and T. pseudomaculata (all n = 10) were allowed to feed on chickens before treatment, and at intervals of 1, 7, 14, 21, 28, 35 and 56 days after treatment, with insect mortality determined. RESULTS: Treatment with two doses of fluralaner showed higher insecticidal efficacy against R. prolixus, T. infestans and T. brasiliensis compared to the single-dose treatment. Similar insecticidal efficacy was observed for T. pseudomaculata for one and two doses of fluralaner. Insecticidal activity of fluralaner (Exzolt®) against triatomine bugs was noted up to 21 and 28 days after treatment with one and two doses of fluralaner, respectively. CONCLUSIONS: The results demonstrate that treatment of chickens with fluralaner (Exzolt®) induces insecticidal activity against triatomines for up to 28 days post-treatment, suggesting its potential use as a control strategy for Chagas disease in endemic areas.

Innate immune receptors are differentially expressed in mice during experimental Schistosoma mansoni early infection

BACKGROUND The impact of Schistosoma mansoni infection over the immune response and the mechanisms involved in pathogenesis are not yet completely understood. OBJECTIVES This study aimed to evaluate the expression of innate immune receptors in three distinct mouse lineages (BALB/c, C57BL/6 and Swiss) during experimental S. mansoni infection with LE strain. METHODS The parasite burden, intestinal tissue oogram and presence of hepatic granulomas were evaluated at 7- and 12-weeks post infection (wpi). The mRNA expression for innate Toll-like receptors, Nod-like receptors, their adaptor molecules, and cytokines were determined at 2, 7 and 12 wpi in the hepatic tissue by real-time quantitative polymerase chain reaction (qPCR). FINDINGS Swiss mice showed 100% of survival, had lower parasite burden and intestinal eggs, while infected BALB/c and C57BL/6 presented 80% and 90% of survival, respectively, higher parasite burden and intestinal eggs. The three mouse lineages displayed distinct patterns in the expression of innate immune receptors, their adaptor molecules and cytokines, at 2 and 7 wpi. MAIN CONCLUSIONS Our results suggest that the pathogenesis of S. mansoni infection is related to a dynamic early activation of innate immunity receptors and cytokines important for the control of developing worms.

Immunological imbalance in microcephalic children with congenital Zika virus syndrome.

Microcephalic children due congenital Zika virus syndrome (CZS) present neurological symptoms already well described. However, several other alterations can also be observed. Here, we aimed to evaluate the immune system of microcephaly CZS children. We showed that these patients have enlarged thymus, spleen and cervical lymph nodes, analysed by ultrasound and compared to the reference values for healthy children. In the periphery, they have an increase in eosinophil count and morphological alterations as hypersegmented neutrophils and atypical lymphocytes, even in the absence of urinary tract infections, parasitological infections or other current symptomatic infections. Microcephalic children due CZS also have high levels of IFN-γ, IL-2, IL-4, IL-5 and type I IFNs, compared to healthy controls. In addition, this population showed a deficient cellular immune memory as demonstrated by the low reactivity to the tuberculin skin test even though they had been vaccinated with BCG less than 2 years before the challenge with the PPD. Together, our data demonstrate for the first time that CZS can cause alterations in primary and secondary lymphoid organs and also alters the morphology and functionality of the immune system cells, which broadens the spectrum of CZS symptoms. This knowledge may assist the development of specific therapeutic and more efficient vaccination schemes for this population of patients.