Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV, USA.
Department of Animal and Poultry Science, Virginia Tech, Blacksburg, VA, USA.
Parasite Immunol. 2020 Nov;42(11):e12773. doi: 10.1111/pim.12773. Epub 2020 Jul 29.
The objective of this study was to identify and characterize cell populations within ovine peripheral blood mononuclear cells (PBMCs) associated with Haemonchus contortus (Hc) larval morbidity and impairment in vitro.
Monocytes and lymphocytes were separated from PBMC from parasite-resistant St. Croix (STC) sheep and parasite-susceptible Suffolk (SUF) sheep. Cells were cultured with Hc third stage larvae (L3) for 9 h. Larval morbidity was assessed using ATP concentration. Activation status was determined through gene expression analysis and enzyme inhibition. Enzymes arginase-1 (Arg1) and inducible nitric oxide synthase (iNOS) were inhibited using BEC (S-(2-boronoethyl)-I-cysteine) and 1400W (N-(3-(aminomethyl)benzyl)acetamidine), respectively. Larval ATP was lower when cultured with STC-derived monocytes (0.015 μmol/L ATP) compared to SUF-derived monocytes (0.067 μmol/L ATP) (P < .001), or lymphocytes from either breed (STC: 0.085 μmol/L, SUF: 0.112 μmol/L ATP) (P < .001). SUF-derived monocytes displayed higher expression of M1 genes, whereas STC-derived monocytes displayed M2 genes continuously. Inhibition of Arg1 decreased monocyte function in both breeds, whereas iNOS inhibition restored SUF-derived monocyte function.
Together, these data indicate STC-derived monocytes favour M2 phenotype when exposed to L3, where SUF-derived monocyte function resembled M1 phenotype and described potential for improving Suffolk sheep through modulating inflammatory responses.
本研究旨在鉴定和描述与捻转血矛线虫（Hc）幼虫发病和体外损伤相关的绵羊外周血单个核细胞（PBMC）中的细胞群。
从抗捻转血矛线虫的圣克鲁斯（STC）绵羊和易感苏福克（SUF）绵羊的 PBMC 中分离单核细胞和淋巴细胞。将细胞与捻转血矛线虫的 3 期幼虫（L3）培养 9 小时。使用 ATP 浓度评估幼虫发病率。通过基因表达分析和酶抑制来确定激活状态。使用 BEC（S-（2-硼乙基）-L-半胱氨酸）和 1400W（N-（3-（氨基甲基）苄基）乙脒）分别抑制酶精氨酸酶-1（Arg1）和诱导型一氧化氮合酶（iNOS）。与 SUF 来源的单核细胞（0.067μmol/L ATP）相比，STC 来源的单核细胞（0.015μmol/L ATP）在与幼虫共培养时的幼虫 ATP 水平更低（P<0.001），或者与任何一种绵羊来源的淋巴细胞（STC：0.085μmol/L，SUF：0.112μmol/L ATP）相比（P<0.001）。SUF 来源的单核细胞显示出更高的 M1 基因表达，而 STC 来源的单核细胞则持续显示出 M2 基因。Arg1 抑制降低了两种绵羊来源的单核细胞的功能，而 iNOS 抑制则恢复了 SUF 来源的单核细胞的功能。
综上所述，这些数据表明，当暴露于 L3 时，STC 来源的单核细胞有利于 M2 表型，而 SUF 来源的单核细胞功能类似于 M1 表型，并描述了通过调节炎症反应来改善苏福克绵羊的潜力。
