Perfil de citocinas e sua relação com a parasitemia em bovinos experimentalmente infectados por Trypanosoma vivax
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Data
2017-11-06
Autores
Fidelis Junior, Otavio Luiz [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Surtos por Trypanosoma vivax têm ocorrido com frequência cada vez maior em rebanhos bovinos no Brasil, porém como a enfermidade não é considerada um problema para o Ministério da Agricultura, Pecuária e Abastecimento (MAPA), não há controle oficial nem registros precisos sobre sua ocorrência, muito embora T. vivax cause grandes prejuízos aos rebanhos onde ocorre. Estabelecer o diagnóstico dessa enfermidade é tarefa desafiadora, pois muitos aspectos clínicos, imunológicos e laboratoriais não estão completamente elucidados. No presente estudo foram avaliadas diferentes técnicas utilizadas para o diagnóstico de T. vivax, a fim de verificar a melhor maneira de usá-las durante o curso da doença. Também se verificou a variação do perfil de citocinas (IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, TNFα e IFNγ) associada à flutuação da parasitemia de T. vivax em três bovinos fêmeas Girolanda experimentalmente infectados (E1 a E3) com 2,0 x 107 tripomastigotas de T. vivax, isolado "Lins”. Para tanto foram utilizadas amostras sanguíneas obtidas sete dias antes da inoculação (D-7), no dia da inoculação (D0), no dia subsequente a inoculação (D1) e posteriormente a cada sete dias até 119 dias após infecção (DAI). Os métodos moleculares demonstraram maiores taxas de detecção (61,1%), enquanto o melhor teste parasitológico detectou apenas 44,4%. Os métodos sorológicos, RIFI e ELISA, detectaram soropositividade em 94,4% e 90,7% das amostras sabidamente positivas, respectivamente. As análises revelaram que a fase aguda da enfermidade pode prolongar-se até 42 DAI, mais do que previamente relatado. O perfil de citocinas apresentado por bovinos no decorrer da infecção apresentou padrão individual e não foi encontrada correlação entre a expressão e a concentração plasmática das citocinas avaliadas. Resposta Th1 foi verificada durante a fase aguda da enfermidade e, no início da fase crônica, foi detectado um aumento das citocinas Th2. Os resultados obtidos contribuirão no entendimento da fisiopatogenia da doença causada por T. vivax e auxiliarão para um refinamento do diagnóstico desta enfermidade.
Trypanosoma vivax outbreaks have been occurring with increasing frequency in Brazilian herds, although the Brazilian Ministry of Agriculture, Livestock and Supply (MAPA) does not consider this disease a problem, there is no official control or accurate records of its occurrence. T. vivax causes great damage to the livestock where it occurs. Establish the disease diagnosis is a challenging task, since many clinical, immunological and laboratory aspects are not completely elucidated. In the present study were evaluated several techniques for T. vivax diagnosis in order to verify the best way of using them during the course of the disease. It was also to evaluate the cytokine profile (IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, TNFα and IFNγ) associated with the parasitemia in three Girolando cows (E1 to E3) experimentally infected with 2.0 x 107 trypomastigotes of T. vivax, isolate "Lins". Blood samples obtained seven days before inoculation (D-7), on the day of inoculation (D0), the day after inoculation (D1) and then every seven days up to 119 days after infection (DAI) were used. Molecular methods showed higher detection rates (61.1%), while the best parasitological test detected only 44.4%. The serological methods, RIFI and ELISA, detected seropositivity in 94.4% and 90.7% of the samples known to be positive, respectively. The analyses revealed that the acute phase of the disease may extend up to 42 days after infection (DAI), longer than previously reported. The cytokine profile presented by cattle, during the course of the infection, presented an individual pattern and no correlation was found between the expression and the plasmatic concentration. Th1 response was verified during the acute phase of the disease and, at the beginning of the chronic phase, an increase of Th2 cytokines was detected. The results obtained will help in understanding the pathophysiology of illness caused by T. vivax and may contribute to a refinement of the disease diagnosis.
Trypanosoma vivax outbreaks have been occurring with increasing frequency in Brazilian herds, although the Brazilian Ministry of Agriculture, Livestock and Supply (MAPA) does not consider this disease a problem, there is no official control or accurate records of its occurrence. T. vivax causes great damage to the livestock where it occurs. Establish the disease diagnosis is a challenging task, since many clinical, immunological and laboratory aspects are not completely elucidated. In the present study were evaluated several techniques for T. vivax diagnosis in order to verify the best way of using them during the course of the disease. It was also to evaluate the cytokine profile (IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, TNFα and IFNγ) associated with the parasitemia in three Girolando cows (E1 to E3) experimentally infected with 2.0 x 107 trypomastigotes of T. vivax, isolate "Lins". Blood samples obtained seven days before inoculation (D-7), on the day of inoculation (D0), the day after inoculation (D1) and then every seven days up to 119 days after infection (DAI) were used. Molecular methods showed higher detection rates (61.1%), while the best parasitological test detected only 44.4%. The serological methods, RIFI and ELISA, detected seropositivity in 94.4% and 90.7% of the samples known to be positive, respectively. The analyses revealed that the acute phase of the disease may extend up to 42 days after infection (DAI), longer than previously reported. The cytokine profile presented by cattle, during the course of the infection, presented an individual pattern and no correlation was found between the expression and the plasmatic concentration. Th1 response was verified during the acute phase of the disease and, at the beginning of the chronic phase, an increase of Th2 cytokines was detected. The results obtained will help in understanding the pathophysiology of illness caused by T. vivax and may contribute to a refinement of the disease diagnosis.
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Palavras-chave
doença dos bovinos, tripanossomíase, citocinas, qPCR, RT-qPCR, ELISA, bovine diseases, trypanosomiasis, cytokine