RESUMEN
Chagas disease is a potentially fatal infection in 21 endemic Latin America countries for which the effectiveness of reference antiparasitic chemotherapy is limited. Thus, we developed three biopharmaceuticals and evaluated the effectiveness of different immunization strategies (recombinant protein NTPDase-1 [rNTPDase-1], DNA plasmid encoding Trypanosoma cruzi NTPDase-1 [TcNTPDase-1] and DNA-NTPDase-1 prime/rNTPDase-1 boost [Prime-boost]) based on the surface ecto-nucleoside triphosphate diphosphohydrolase (ecto-NTPDase) enzyme of T. cruzi in animals challenged with a virulent strain (Y) of this parasite. BALB/c mice were immunized three times at 30 days intervals, challenged with T. cruzi 15 days after the last immunization, and euthanized 30 days after T. cruzi challenge. Our results showed limited polarization of specific anti-ecto-NTPDase immunoglobulins in mice receiving both immunization protocols. Conversely, the Prime-boost strategy stimulated the Th1 protective phenotype, upregulating TNF-α and downregulating IL-10 production while increasing the activation/distribution of CD3+/CD8+, CD4+/CD44hi and CD8+/CD44hi/CD62L cells in immunized and infected mice. Furthermore, IL-6 and IL10 levels were reduced, while the distribution of CD4+/CD44hi and CD3+/CD8+ cells was increased from rNTPDase-1 and DNA-NTPDase1-based immunization strategies. Animals receiving DNA-NTPDase1 and Prime-boost protocols before T. cruzi challenged exhibited an enhanced immunological response associated with IL-17 upregulation and remarkable downregulation of heart parasitism (T. cruzi DNA) and mortality. These findings indicated that NTPDase-1 with Prime-boost strategy induced a protective and sustained Th17 response, enhancing host resistance against T. cruzi. Thus, ecto-NTPDase is a potentially relevant and applicable in the development of biopharmaceuticals with greater immunoprophylactic potential for Chagas disease.
Asunto(s)
Productos Biológicos , Enfermedad de Chagas , Trypanosoma cruzi , Animales , Antiparasitarios , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/prevención & control , Interleucina-10 , Interleucina-17 , Interleucina-6 , Ratones , Ratones Endogámicos BALB C , Nucleósidos , Polifosfatos , Proteínas Recombinantes/farmacología , Factor de Necrosis Tumoral alfaRESUMEN
Research involving the use of nematophagous fungi in the biological control of parasites of interest to veterinarians has occurred over recent years, with promising results. This article reports the infection of Parascaris equorum eggs by the fungus Pochonia chlamydosporia (isolates VC1 and VC4). Six groups were formed for each isolate, with six different culture media: 2% water-agar (2% WA); agar-chitin (AC); YPSSA (yeast extract, K2HPO4, MgSO4 ·7H2O, soluble starch); AELA extract (starch + water + agar); 2% corn-meal-agar (2% CMA); and 2% potato dextrose-agar (2% PDA). A total of 1000 eggs of P. equorum were transferred to each plate containing isolates grown for a period of 7 days (treatment group). Also, 1000 eggs were added to each plate without fungus (controlgroup). The plates were kept in an environmental chamber at 25 °C in the dark for 21 days. After, we analyzed the effects on ovicidal activity: effect 1 (accession shell); effect 2 (penetration hyphae); and effect 3 (destruction of the eggs). No differences were observed in the destruction of eggs between the two isolates. The decreasing effectiveness of the different culture media was: PDA (38.9%); CMA (38.3%); WA (36.7%); YPSSA (36.45%); and AC (32.5%). The highest percentage egg destruction was observed when the strains were grown in culture medium AELA (44.9%); this was the best medium.
Asunto(s)
Ascaridoidea/microbiología , Interacciones Huésped-Patógeno , Hypocreales/crecimiento & desarrollo , Cigoto/microbiología , Animales , Antibiosis , Medios de Cultivo/química , Oscuridad , Hypocreales/fisiología , Análisis de Supervivencia , Temperatura , TiempoRESUMEN
The nematode Angiostrongylus cantonensis causes eosinophilic meningoencephalitis in humans and thus alternative methods of control should be studied. The objective of this work was to evaluate the predatory capacity of eight fungal isolates of the species Duddingtonia flagrans (AC001, CG768 and CG722), Monacrosporium thaumasium (NF34), M. sinense (SF53) and Arthrobotrys robusta (I31), A. cladodes (CG719) and A. conoides (I40) on first-stage larvae (L1) of A. cantonensis under laboratory conditions. The treated groups contained 1000 conidia of the fungal isolates and 1000 A. cantonensis L1 in Petri dishes containing 2% water-agar medium (2% WA). The control group (without fungi) contained only 1000 A. cantonensis L1 in 2% WA. Evidence of predation was observed at the end of 7 days. Percentage reductions in L1 were: AC001, 82.8%; CG768, 71.0%; CG722, 72.8%; NF34, 86.7%; SF53, 89.7%; I40, 48.3%; CG719, 84.7%; and I31, 80.4%. No significant difference was observed (p>0.01) between the actions of the isolates used; however, a difference was noted (p<0.01) in relation to the control group. The results of the present work, confirm previous reports of the effectiveness of the fungi D. flagrans, M. thaumasium, M. sinense and A. robusta in controlling larvae of potentially zoonotic nematodes, this being the first report on A. cantonensis L1.
Asunto(s)
Angiostrongylus cantonensis/microbiología , Hongos/fisiología , Animales , Interacciones Huésped-Patógeno , Larva/microbiologíaRESUMEN
The predatory nematophagous fungi have been used as an alternative control of gastrointestinal nematodes of domestic animals in natural and laboratory conditions. However, it is unclear if the association of some of these species could bring some kind of advantage, from a biological standpoint. In this context, this study consisted of two tests in vitro: in assay A, the assessment of the viability of the association of pellets in sodium alginate matrix containing the fungus Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) and its predatory activity on infective larvae (L3) of cyathostomin after passing through the gastrointestinal tract of horses and assay B, assessment of the cyathostomin L3 reduction percentage in coprocultures. Twelve crossbred horses, females, with a mean weight of 356 kg and previously dewormed were divided in three groups with four animals each: group 1, each animal received 50 g of pellets containing mycelial mass of the fungus D. flagrans and 50 g of pellets of the fungus M. thaumasium, associated and in a single oral dose; group 2, 100 g of pellets containing D. flagrans and 100 g of pellets containing M. thaumasium, associated and in a single oral dose; group 3, control. Faecal samples were collected from animals in the treated and control groups at time intervals of 12, 24, 36, 48, 60 and 72 h after the administration of treatments and placed in Petri dishes containing 2% water-agar (assay A) and cups for coprocultures (assay B). Subsequently, 1000 cyathostomin L3 were added to each Petri dish (assay A) and 1000 cyathostomin eggs were added to each coproculture (assay B) of fungi-treated and control groups. At the end of 15 days, there was observed that the two associations of pellets containing the fungi tested showed predatory activity after passing through the gastrointestinal tract of horses (assay A). In assay B, all the intervals studied showed reduction rate in the number of L3 recovered from coprocultures exceeding 80%. However, no difference (p>0.01) was seen in recovery of not predated L3 between the fungi-treated groups in the time intervals studied. The results obtained showed that the associations of pellets (50 or 100 g of each fungal isolate) were viable after passage through the gastrointestinal tract in horses and could be used in natural conditions.