T Cell Subpopulations in Healthy Elderly and Lung Cancer Patients: Insights from Cuban Studies.
T Cell Subpopulations in Healthy Elderly and Lung Cancer Patients: Insights from Cuban Studies.
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DOI：
10.3389/fimmu.2017.00146
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发表时间：
2017
影响因子：
7.3
通讯作者：
Lage A
中科院分区：
文献类型：
--
作者：
Saavedra D;Garcia B;Lage A
随着年龄的增长，免疫系统的衰老和患癌症的风险也会增加。年龄本身会引起免疫系统的变化，这与幼稚淋巴细胞胸腺输出的减少、慢性抗原负荷的积累，特别是巨细胞病毒（CMV）等慢性病毒感染以及淋巴细胞的复制性衰老有关。这些变化最终可能会增加癌症风险并影响对癌症治疗的反应。然而，一些混杂因素使得绘制因果关系变得困难。对不同人群的研究有助于阐明这些复杂的关系。在这里，我们总结了目前关于 T 细胞衰老、与 CMV 感染、癌症和癌症治疗的关系的知识。我们还回顾了在古巴进行的一系列研究的结果，古巴人口的特点是预期寿命长和抗原载量高，包括热带国家典型的巨细胞病毒血清阳性率高。尽管免疫衰老影响免疫反应的几乎所有组成部分和功能，但其最显着的特征是幼稚CD8+ T淋巴细胞数量和比例的减少以及终末分化CD8+ T淋巴细胞的增加。这些特征得到了古巴研究的证实，但有趣的是，明显的性别效应也出现了。此外，由于老龄化是一种全球现象，预计患有恶性肿瘤的老年人将迅速增加；因此，对患者免疫状态的评估将支持免疫治疗的决定并预测此类治疗的疗效，从而提高患者的获益。
The senescence of the immune system and the risk of cancer increase with aging. Age itself entails changes in the immune system, which are related to a decrease in thymic output of naïve lymphocytes, an accumulation of chronic antigenic load, notably chronic viral infections such as cytomegalovirus (CMV), and replicative senescence of lymphocytes. These changes could eventually contribute to cancer risk and affect the response to cancer treatment. However, several confounding factors make it difficult to draw a picture of causal relationships. Studies in diverse human populations could contribute to clarify these complex relationships. Here, we summarize the current knowledge about the senescence of the T cells, the relationship with CMV infection, cancer, and cancer treatment. We also review the results of a series of studies performed in Cuba whose population is characterized by the unusual combination of long life expectancy and high antigenic load, including high seroprevalence of CMV, typical of tropical countries. Although immunosenescence affects almost all components and functions of the immune response, its most salient feature is a decrease in numbers and proportions of naïve CD8+ T lymphocytes and an accretion of terminally differentiated CD8+ T lymphocytes. These features were confirmed by the Cuban studies, but interestingly a clear gender effect also appeared. Moreover, as aging is a global phenomenon, a fast increase in elderly with malignancies is expected; therefore, the evaluation of patient’s immune status would support the decision of treating them with immunotherapy and predict the efficacy of such treatments, thereby improving benefits for the patients.