IgE antibodies from schistosomiasis patients to recognize epitopes in potato apyrase

Abstract INTRODUCTION: High percentages of structural identity and cross-immunoreactivity have been reported between potato apyrase and Schistosoma mansoni ATP diphosphohydrolase (SmATPDases) isoforms, showing the existence of particular epitopes shared between these proteins. METHODS: Potato apyrase was employed using ELISA, western blot, and mouse immunization methods to verify IgE reactivity. RESULTS: Most of the schistosomiasis patient's (75%) serum was seropositive for potato apyrase and this protein was recognized using western blotting, suggesting that parasite and plant proteins share IgE-binding epitopes. C57BL/6 mice immunized with potato apyrase showed increased IgE antibody production. CONCLUSIONS: Potato apyrase and SmATPDases have IgE-binding epitopes.

Hospitalizations for cardiovascular diseases and the coverage by the family health strategy / Internações por doenças cardiovasculares e a cobertura da estratégia saúde da família / Internaciones por enfermedades cardiovasculares y la cobertura de la estrategia salud de la familia

AbstractObjective: to verify the correlation between the rates of hospitalization for primary care-sensitive cardiovascular diseases and the coverage by the Family Health Strategy of residents of the State of Paraná, by regional health divisions, from 2000 to 2011.Method: ecological study developed from data of the Hospital Information System of the Brazilian Unified Health System (SUS) and the Department of Primary Care of the Ministry of Health. The rates of hospitalization for cardiovascular diseases were correlated with the annual coverage by the Family Health Strategy using Pearson's and Spearman's correlation coefficients.Result: there was a strong and negative correlation in the State of Paraná (r=-0.91; p <0.001) and in most regional health divisions, with the highest correlations observed in the Metropolitan and Toledo (r =-0.93; p<0.001) and Paranaguá (r=-0.92, p<0.001) regional health divisions.Conclusion: the results suggest that the increase in the coverage by the Family Health Strategy was an important factor for decrease in the hospitalizations for cardiovascular conditions among residents of the State of Paraná and in most regional health divisions. Other studies should be performed to analyze the factors and causes in regional health divisions where there was no correlation with increase in the Family Health Strategy.

ResumoObjetivo:verificar a correlação entre taxas de internação por doenças cardiovasculares sensíveis à atenção primária e a cobertura da Estratégia Saúde da Família de residentes no estado do Paraná, por regionais de saúde, no período de 2000 a 2011.Método:estudo ecológico, desenvolvido a partir de dados do Sistema de Informações Hospitalares do Sistema Único de Saúde e do Departamento de Atenção Básica do Ministério da Saúde. Correlacionaram-se as taxas de internação por doenças cardiovasculares com as coberturas anuais da Estratégia Saúde da Família, utilizando-se os coeficientes de correlação de Pearson e Spearman.Resultado:houve correlação negativa e forte no estado do Paraná (r=-0,91; p<0,001) e na maioria das regionais de saúde, sendo maior na Metropolitana e Toledo (r=-0,93; p<0,001) e Paranaguá (r=-0,92; p<0,001).Conclusão:os resultados sugerem que o aumento da cobertura da Estratégia Saúde da Família foi fator importante para a diminuição das internações por condições cardiovasculares em residentes no estado do Paraná e na maioria das regionais de saúde. Outros estudos devem ser realizados para analisar fatores e causas nas regiões do estado onde não houve correlação com incremento da Estratégia Saúde da Família.

ResumenObjetivo:verificar la correlación entre tasas de internación por enfermedades cardiovasculares sensibles a la atención primaria y la cobertura de la Estrategia Salud de la Familia de residentes en el estado de Paraná, por regionales de salud, en el período de 2000 a 2011.Método:estudio ecológico, desarrollado a partir de datos del Sistema de Informaciones Hospitalarias del Sistema Único de Salud y del Departamento de Atención Básica del Ministerio de la Salud. Se correlacionaron las tasas de internación por enfermedades cardiovasculares con las coberturas anuales de la Estrategia Salud de la Familia, utilizando los coeficientes de correlación de Pearson y Spearman.Resultado:hubo correlación negativa y fuerte en el estado de Paraná (r=-0,91; p<0,001) y en la mayoría de las regionales de salud, siendo mayor en la Metropolitana y Toledo (r=-0,93; p<0,001) y Paranaguá (r=-0,92; p<0,001).Conclusión:los resultados sugieren que el aumento de la cobertura de la Estrategia Salud de la Familia fue un factor importante para la disminución de las internaciones por condiciones cardiovasculares en residentes en el estado de Paraná y en la mayoría de las regionales de salud. Otros estudios deben ser realizados para analizar factores y causas en las regiones del estado en donde no hubo correlación con incremento de la Estrategia Salud de la Familia.

Immunostimulatory property of a synthetic peptide belonging to the soluble ATP diphosphohydro-lase isoform (SmATPDase 2) and immunolocalisation of this protein in the Schistosoma mansoni egg

A peptide (SmB2LJ; r175-194) that belongs to a conserved domain from Schistosoma mansoni SmATPDase 2 and is shared with potato apyrase, as predicted by in silico analysis as antigenic, was synthesised and its immunostimulatory property was analysed. When inoculated in BALB/c mice, this peptide induced high levels of SmB2LJ-specific IgG1 and IgG2a subtypes, as detected by enzyme linked immunosorbent assay. In addition, dot blots were found to be positive for immune sera against potato apyrase and SmB2LJ. These results suggest that the conserved domain r175-194 from the S. mansoni SmATPDase 2 is antigenic. Western blots were performed and the anti-SmB2LJ antibody recognised in adult worm (soluble worm antigen preparation) or soluble egg antigen antigenic preparations two bands of approximately 63 and 55 kDa, molecular masses similar to those predicted for adult worm SmATPDase 2. This finding strongly suggests the expression of this same isoform in S. mansoni eggs. To assess localisation of SmATPDase 2, confocal fluorescence microscopy was performed using cryostat sections of infected mouse liver and polyclonal antiserum against SmB2LJ. Positive reactions were identified on the external surface from the miracidium in von Lichtenberg's envelope and, in the outer side of the egg-shell, showing that this soluble isoform is secreted from the S. mansoni eggs.

Detection of IgG1 and IgG4 subtypes reactive against potato apyrase in schistosomiasis patients

In this paper, we showed for the first time that the conserved domains within Schistosoma mansoni ATP diphosphohydrolase isoforms, shared with potato apyrase, possess epitopes for the IgG1 and IgG4 subtypes, as 24 (80 percent) of the 30 schistosomiasis patients were seropositive for this vegetable protein. The analyses for each patient cured (n = 14) after treatment (AT) with praziquantel revealed variable IgG1 and IgG4 reactivity against potato apyrase. Different antigenic epitopes shared between the vegetable and parasite proteins could be involved in susceptibility or resistance to S. mansoni AT with praziquantel and these possibilities should be explored.

Antibody reactivity against potato apyrase, a protein that shares epitopes with Schistosoma mansoni ATP diphosphohydrolase isoforms, in acute and chronically infected mice, after chemotherapy and reinfection

Schistosoma mansoni ATP diphosphohydrolase isoforms and potato apyrase share conserved epitopes. By enzyme-linked immunosorbent assays, elevated levels of IgM, IgG2a and IgG1 antibody reactivity against potato apyrase were observed in S. mansoni-infected BALB/c mice during the acute phase of infection, while only IgM and IgG1 antibody reactivity levels maintained elevated during the chronic phase of infection. Antibody reactivity against potato apyrase was monitored over an 11-month period in chronically-infected mice treated with oxamniquine. Eleven months later, the level of seropositive IgM decreased significantly (~30 percent) compared to the level found in untreated, infected mice. The level of seropositive IgG1 decreased significantly four months after treatment (MAT) (61 percent) and remained at this level even after 11 months. The IgG2a reactivity against potato apyrase, although unchanged during chronic phase to 11 MAT, appeared elevated again in re-infected mice suggesting a response similar to that found during the acute phase. BALB/c mouse polyclonal anti-potato apyrase IgG reacted with soluble egg antigens probably due to the recognition of parasite ATP diphosphohydrolase. This study, for the first time, showed that the IgG2a antibody from S. mansoni-infected BALB mice cross-reacts with potato apyrase and the level of IgG2a in infected mice differentiates disease phases. The results also suggest that different conserved-epitopes contribute to the immune response in schistosomiasis.

Cross-immunoreactivity between anti-potato apyrase antibodies and mammalian ATP diphosphohydrolases: potential use of the vegetal protein in experimental schistosomiasis

We have previously showed that Schistosoma mansoni ATP-diphosphohydrolase and Solanum tuberosum potato apyrase share epitopes and the vegetable protein has immunostimulatory properties. Here, it was verified the in situ cross-immunoreactivity between mice NTPDases and anti-potato apyrase antibodies produced in rabbits, using confocal microscopy. Liver samples were taken from Swiss Webster mouse 8 weeks after infection with S. mansoni cercariae, and anti-potato apyrase and TRITC-conjugated anti-rabbit IgG antibody were tested on cryostat sections. The results showed that S. mansoni egg ATP diphosphohydrolase isoforms, developed by anti-potato apyrase, are expressed in miracidial and egg structures, and not in granulomatous cells and hepatic structures (hepatocytes, bile ducts, and blood vessels). Therefore, purified potato apyrase when inoculated in rabbit generates polyclonal sera containing anti-apyrase antibodies that are capable of recognizing specifically S. mansoni ATP diphosphohydrolase epitopes, but not proteins from mammalian tissues, suggesting that autoantibodies are not induced during potato apyrase immunization. A phylogenetic tree obtained for the NTPDase family showed that potato apyrase had lower homology with mammalian NTPDases 1-4, 7, and 8. Further analysis of potato apyrase epitopes could implement their potential use in schistosomiasis experimental models.