Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections

An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

Avaliação da aplicação terapêutica de imunoglobulina Y em macacos cynomolgus infectados com rotavírus humano / Evaluation of therapeutic application of immunoglobulin y in cynomolgus monkeys infected with rotavirus human

O rotavírus é a causa mais frequente de gastroenterite aguda (GA) em crianças menores decinco anos de idade em todo o mundo, sendo responsável por até 200 mil mortes anualmente.Sua disseminação ocorre pelo contato pessoa-pessoa, principalmente pela via de transmissãofecal-oral. Embora haja vacinas disponíveis e em desenvolvimento para a rotavirose, medidasalternativas são necessárias como, por exemplo, nos casos de surto. Dessa forma, a utilizaçãode imunoglobulina Y (IgY) em imunoterapia passiva é justificável. A IgY é a imunoglobulinaque predomina na circulação das aves, sendo transferida por secreção ativa do sangue para agema dos ovos, a partir da qual a purificação é realizada para obtenção dos anticorposespecíficos de interesse. As vantagens apresentadas por esta metodologia incluem: fácilobtenção, baixo custo e capacidade de produção em larga escala de modo adequado a umpadrão bioético mais atual. É crescente sua aplicação em métodos de diagnóstico eimunoterapia passiva. Neste estudo, avaliamos a infectividade do rotavírus A (RVA) humanoem macacos cynomolgus (Macaca fascicularis) e a aplicação terapêutica da IgY específicaanti-rotavírus após desafio com RVA pela via oral. Os animais que receberam o tratamentoforam divididos em dois grupos: um recebeu IgY apenas pela via oral e outro pela via oral eintravenosa. Os animais foram acompanhados por cinco dias e foram avaliados sinais clínicos,carga viral sérica e fecal, hematologia e dosagem de eletrólitos séricos. Além disso, buscou-sedefinir o perfil de células do sistema imune no sangue periférico, assim como detecção decitocinas no soro dos animais, ensaios de imunofluorescência para detecção da proteína nãoestrutural do rotavírus e também das células do sistema imune em cortes congelados deintestino...

Rotavirus is the most common cause of acute gastroenteritis in children under five years oldworldwide, accounting for about 200,000 deaths per year. Its spread is due to person to personcontact, mainly through fecal-oral transmission. Although there are vaccines available forrotavirus, alternative measures are required, for example, in outbreaks. Thus, the use ofimmunoglobulin Y (IgY) in passive immunotherapy is justified. The IgY is the predominantimmunoglobulin in birds circulation, being transferred from the blood by active secretion intothe yolk of eggs from which the purification is performed to obtain the specific antibody ofinterest. The advantages presented by this methodology include: easy obtainment, low cost,and production capacity in large-scale, appropriate considering current bioethical guiderlines.IgY is increasing employed in methods of diagnosis and passive immunotherapy. This studyevaluated the infectivity of human rotavirus A (RVA) in cynomolgus monkeys (Macacafascicularis) and therapeutic function of IgY after challenge with RVA orally. The animalswere divided in two groups: one that received IgY only by oral route and the other by oral andintravenous routes. We followed up the animals for five days through clinical manifestations,serum and fecal viral load, hematology and dosage of serum electrolytes. Moreover, weinvestigated the profile of immune cells in peripheral blood, detection of cytokines in theserum, immunofluorescence assays for the detection of rotavirus non-structural protein andimmune cells in the intestine. The absence of diarrhea episodes was considered a good signfor the clinical efficacy of IgY immunotherapy, however, viral RNA was found in the stool ofsome animals. The group treated with IgY orally and intravenously was the one in which wedid not detect viral genome in faeces. As for the cell populations in peripheral blood, it wasnot observed significant difference between groups...