Fries-Craft Krysten, Meyer Meaghan M, Sato Yuko, El-Gazzar Mohamed, Bobeck Elizabeth A
Department of Animal Science, Iowa State University, Ames, IA, United States.
Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, United States.
Front Vet Sci. 2021 Mar 26;8:653129. doi: 10.3389/fvets.2021.653129. eCollection 2021.
In 2018 and 2019, was isolated from multiple post-molt commercial laying hens with unusually high mortality. A challenge study was conducted to elucidate the role of in this disease outbreak and the work herein represents the assessment of immunological responses in laying hens experimentally infected with isolates from these cases. A total of 200 laying hens at 22 or 96 weeks of age (100/ age group) were assigned to 1 of 4 experimental inoculation groups (negative control, oral gavage, subcutaneous injection, or intravenous injection) after a 72 h acclimation period. Blood samples were taken prior to inoculation (baseline), 6 h post-inoculation (pi), 24 hpi, 3 dpi, and 7 dpi. Additional spleen samples to further assess systemic immunity were taken at baseline, 3 and 8 dpi. Metabolic phenotypes of peripheral blood mononuclear cells (PBMC) were isolated and assessed by Seahorse metabolic assay. Immune cell profiles in the spleen and PBMC were assessed by multicolor flow cytometry. At baseline, 96-week-old laying hens had 26.7% fewer PBMC-derived T cells compared to 22-week-old birds. Older hens had 28.9% increased helper T cell (T) populations and 60.5% reduced γδ T cells ( = 0.03 and < 0.0001) which may contribute to variable clinical responses between age groups; however, no age-related differences in metabolic potential were observed. Metabolic outcomes showed that birds remained stressed from transport and re-housing past a 72 h acclimation period and through 24 h- 3 days post-inoculation. Inoculation with generally reduced oxidative and glycolytic potentials compared to the control, with the greatest reductions observed in birds inoculated by intravenous injection ( < 0.05). Overall CD3 T cell populations showed significant reductions in the intravenous group compared to other inoculation routes from 24 hpi to 7 dpi (23.6-39.0%; ≤ 0.0001). These results suggest that age-related baseline differences in T cell populations and changes to T cell subpopulations and other immune cells due to inoculation route may have an additive effect on - induced reductions in metabolic potential; however, further research linking metabolic potential and immune cell profiles is needed.
2018年和2019年，从多只产蛋后期商业蛋鸡中分离出[病原体名称未给出]，这些蛋鸡死亡率异常高。开展了一项攻毒研究以阐明[病原体名称未给出]在此次疾病暴发中的作用，本文的工作代表了对实验感染这些病例分离出的[病原体名称未给出]的蛋鸡免疫反应的评估。在72小时的适应期后，将总共200只22周龄或96周龄的蛋鸡（每个年龄组100只）分配到4个实验接种组之一（阴性对照、口服灌胃、皮下注射或静脉注射）。在接种前（基线）、接种后6小时（pi）、24小时pi、3天pi和7天pi采集血样。在基线、3天pi和8天pi采集额外的脾脏样本以进一步评估全身免疫。通过海马代谢分析分离并评估外周血单个核细胞（PBMC）的代谢表型。通过多色流式细胞术评估脾脏和PBMC中的免疫细胞谱。在基线时，与22周龄的蛋鸡相比，96周龄的蛋鸡PBMC来源的T细胞减少了26.7%。老龄蛋鸡辅助性T细胞（Th）群体增加了28.9%，γδT细胞减少了60.5%（P = 0.03和P < 0.0001），这可能导致不同年龄组之间临床反应的差异；然而，未观察到与年龄相关的代谢潜能差异。代谢结果表明，蛋鸡在72小时的适应期过后以及接种后24小时至3天内，仍因运输和重新安置而处于应激状态。与对照组相比，接种[病原体名称未给出]通常会降低氧化和糖酵解潜能，静脉注射接种的蛋鸡中观察到的降低最为明显（P < 0.05）。从接种后24小时到7天，与其他接种途径相比，静脉注射组的总体CD3 + T细胞群体显著减少（23.6 - 39.0%；P ≤ 0.0001）。这些结果表明，T细胞群体中与年龄相关的基线差异以及接种途径导致的T细胞亚群和其他免疫细胞的变化可能对[病原体名称未给出]诱导的代谢潜能降低产生累加效应；然而，需要进一步研究将代谢潜能与免疫细胞谱联系起来。
