Immune response of sheep naturally infected with Haemonchus spp. on pastures with two different nutritional conditions

Abstract

Parasitic nematodes in the gastrointestinal tract of small ruminants are considered one of the main causes of economical and productive losses. Haemonchus contortus is characterized as the major parasite affecting sheep worldwide. This study was designed to evaluate immunological responses in sheep naturally infected with Haemonchus spp. in two different feed grounds: native and cultivated pasture. Fecal and blood samples were collected weekly from fifteen Corriedale sheep, ages 8 to 12 months, to determine the counting of eggs per gram of feces (EPG), and the concentration of haematocrit, eosinophils, and cytokines during an 84-day experiment. Bromatological analysis of the two pasture treatments (types) showed levels of crude protein and non-fibrous carbohydrates of 9.7% and 12.3% in the native pasture and 14.3% and 23.7% for the cultivated pasture, respectively. No significant difference in haematocrit concentration was found during the experiment between different pastures (p < 0.05). However, significant differences were found in EPG, eosinophils, interleukins, and immunoglobulins levels after 21 days in the cultivated (nutritionally-enhanced) pasture. These data suggest that immune response was characterized in sheep by significantly higher peripheral eosinophilia and an increase in serum concentrations of IgE, IgA, IgG, TNF-β, IFN-γ, and IL-6. Likewise, the improvement in forage condition resulted in a reduction of EPG and an increase of elements that improve a sheep's immune system response against Haemonchus spp. infection. Key words: Cytokines. Gastrointestinal nematode. Immunity. Protein diet. ResumoParasitas nematódeos do trato gastrointestinal de pequenos ruminantes são considerados uma das principais causas de perdas econômicas e produtivas. Haemonchus contortus é caracterizado como o parasita mais importante afetando ovinos em todo o mundo. Este estudo foi delineado para avaliar a resposta imunológica de ovinos naturalmente infectados com Haemonchus spp. em dois grupos alimentares diferentes: pastagem nativa e cultivada. Amostras de fezes e de sangue foram coletadas semanalmente de quinze ovinos Corriedale, com de 8 a 12 meses de idade, para determinar a contagem de ovos por grama de fezes (OPG), e a concentração do hematócrito, eosinófilos e citocinas durante 84 dias de experimento. Análises bromatológicas dos dois tratamentos de pastagens (tipos) demonstraram níveis de proteína bruta e carboidratos não-fibrosos de 9.7% e 12.3% na pastagem nativa e 14.3% e 23.7% para pastagem cultivada, respectivamente. Não foi encontrada diferença significativa na concentração do hematócrito durante o experimento entre as diferentes pastagens (p < 0,05). Entretanto, foram encontradas diferenças significativas no OPG, eosinófilos, interleucinas e níveis de imunoglobulinas depois de 21 na pastagem cultivada (melhorada nutricionalmente). Estes dados sugerem que a resposta imune em ovinos foi caracterizada por significativa elevação da eosinofilia periférica e aumento das concentrações séricas de IgE, IgA, I...

RIG-I Has a Role in Immunity Against Haemonchus contortus, a Gastrointestinal Parasite in Ovis aries: A Novel Report

“…It is reported that Haemonchus contortus excretory and secretory proteins (HcESPs) can bind to goat peripheral blood mononuclear cells. HcESPs affected the biological functions of the cell, such as cell proliferation, cytokine production, cell migration, and nitric oxide production of goat PBMCs ( 33 ). A gradual decrease in interleukin-4 and interferon-γ was observed in PBMCs; in contrast, there was an increase in the concentration of IL-10 and IL-17 ( 34 ).…”

Role of IL-6 and IL10 immune response genes against nematodeHaemonchus contortusin ovis aries- a novel report

“…circumcincta infection was found in the abomasal tissue of susceptible Blackface sheep and resistant Angus heifers that had been exposed to the Cooperiaoncophora and GINs Ostertagiaostertagi, research demonstrated greater production of proinflammatory cytokines such as Il-6 (Li et al, 2007 and Gossner et al, 2012). In sheep that were naturally infected with Haemonchus species under two different nutritional conditions, the immunological response was characterised by significantly enhanced peripheral eosinophilia and an increase in blood concentrations of IgE, IgA, IgG, TNF β, and IL-6 (Toscan et al, 2017). IL-6, an immune response gene, can be used in a variety of ways to treat illness.…”