Seasonal influenza virus infection is a significant cause of morbimortality in the elderly. However, there is poor vaccine efficacy in this population due to immunosenescence. We aimed to explore several homeostatic parameters in the elderly that could impact influenza vaccine responsiveness. Subjects (> 60 years old) who were vaccinated against influenza virus were included, and the vaccine response was measured by a haemagglutination inhibition (HAI) test. At baseline, peripheral CD4 and CD8 T-cells were phenotypically characterized. Thymic function and the levels of different inflammation-related biomarkers, including Lipopolysaccharide Binding Protein (LBP) and anti-cytomegalovirus (CMV) IgG antibodies, were also measured. Influenza vaccine non-responders showed a tendency of higher frequency of regulatory T-cells (Tregs) before vaccination than responders (1.49 [1.08–1.85] vs. 1.12 [0.94–1.63], respectively, p = 0.061), as well as higher expression of the proliferation marker Ki67 in Tregs and different CD4 and CD8 T-cell maturational subsets. The levels of inflammation-related biomarkers correlated with the frequencies of different proliferating T-cell subsets and with thymic function (e.g., thymic function with D-dimers, r = − 0.442, p = 0.001). Age-related homeostatic dysregulation involving the proliferation of CD4 and CD8 T-cell subsets, including Tregs, was related to a limited responsiveness to influenza vaccination and a higher inflammatory status in a cohort of elderly people.

中文翻译：

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稳态 T 细胞增殖对老年人流感疫苗反应性的影响

季节性流感病毒感染是老年人死亡的重要原因。然而，由于免疫衰老，该人群的疫苗效力较差。我们旨在探索老年人中可能影响流感疫苗反应性的几个稳态参数。包括接种流感病毒疫苗的受试者（> 60 岁），并通过血凝抑制 (HAI) 测试测量疫苗反应。在基线时，外周 CD4 和 CD8 T 细胞具有表型特征。还测量了胸腺功能和不同炎症相关生物标志物的水平，包括脂多糖结合蛋白 (LBP) 和抗巨细胞病毒 (CMV) IgG 抗体。流感疫苗无应答者在接种前显示出比应答者更高频率的调节性 T 细胞 (Tregs) 的趋势（分别为 1.49 [1.08-1.85] vs. 1.12 [0.94-1.63]，p = 0.061），以及更高的增殖标志物 Ki67 在 Treg 和不同的 CD4 和 CD8 T 细胞成熟亚群中的表达。炎症相关生物标志物的水平与不同增殖 T 细胞亚群的频率和胸腺功能相关（例如，D-二聚体的胸腺功能，r = - 0.442，p = 0.001）。与年龄相关的稳态失调涉及 CD4 和 CD8 T 细胞亚群（包括 Tregs）的增殖，这与一组老年人对流感疫苗的有限反应和较高的炎症状态有关。以及 Tregs 和不同 CD4 和 CD8 T 细胞成熟亚群中增殖标志物 Ki67 的更高表达。炎症相关生物标志物的水平与不同增殖 T 细胞亚群的频率和胸腺功能相关（例如，D-二聚体的胸腺功能，r = - 0.442，p = 0.001）。与年龄相关的稳态失调涉及 CD4 和 CD8 T 细胞亚群（包括 Tregs）的增殖，这与一组老年人对流感疫苗的有限反应和较高的炎症状态有关。以及 Tregs 和不同 CD4 和 CD8 T 细胞成熟亚群中增殖标志物 Ki67 的更高表达。炎症相关生物标志物的水平与不同增殖 T 细胞亚群的频率和胸腺功能相关（例如，D-二聚体的胸腺功能，r = - 0.442，p = 0.001）。与年龄相关的稳态失调涉及 CD4 和 CD8 T 细胞亚群（包括 Tregs）的增殖，这与一组老年人对流感疫苗的有限反应和较高的炎症状态有关。D-二聚体的胸腺功能，r = - 0.442，p = 0.001）。与年龄相关的稳态失调涉及 CD4 和 CD8 T 细胞亚群（包括 Tregs）的增殖，这与一组老年人对流感疫苗的有限反应和较高的炎症状态有关。D-二聚体的胸腺功能，r = - 0.442，p = 0.001）。与年龄相关的稳态失调涉及 CD4 和 CD8 T 细胞亚群（包括 Tregs）的增殖，这与一组老年人对流感疫苗的有限反应和较高的炎症状态有关。