Mbawuike I N, Lange A R, Couch R B
Department of Microbiology and Immunology, Baylor College of Medicine, Houston, Texas 77030.
Viral Immunol. 1993 Spring;6(1):55-64. doi: 10.1089/vim.1993.6.55.
Influenza A virus-specific MHC class I-restricted cytotoxic T lymphocyte (CTL) activities among young and elderly adults were compared. Peripheral blood lymphocytes from 10 young adults, (mean age 27 +/- 2.4 years) and elderly persons (mean age 71 +/- 1.6 years) were stimulated with influenza A/Taiwan/1/86 (H1N1) virus for 7 days and assayed for lytic activity against A/Taiwan, A/Shanghai (H3N2), and B/USSR virus-infected autologous target cells. Young adults exhibited significantly higher influenza A cross-reactive CTL activity against A/H1N1 and A/H3N2 target cells when compared to aged persons. This was true at all effector-to-target cell ratios tested. Negligible lysis of B/USSR-infected target cells or nonautologous A/Taiwan-infected cells was observed. The number of leukocytes recovered per milliliter of blood was also significantly higher in young adults than in old donors; however, the percentage of CD45+ (common leukocyte antigen), CD3+ (T cells), CD4+ (T helper), and CD8+ (T cytotoxic/suppressor) as well as the CD4+/CD8+ ratios was similar in both groups. Depletion of cells with monoclonal antibodies indicated that the effector cells were CD8+ T cells. Serum-neutralizing antibody (Nt Ab) titers were similar among young and elderly persons and there was no correlation between Nt Ab and CTL activity. These results demonstrate a reduced influenza virus-specific MHC class I-restricted CTL activity among elderly persons. The deficiency in this cell-mediated immune function may contribute to the morbidity and mortality from influenza virus infections in this population.
比较了年轻人和老年人中甲型流感病毒特异性的主要组织相容性复合体I类限制性细胞毒性T淋巴细胞（CTL）活性。来自10名年轻成年人（平均年龄27±2.4岁）和老年人（平均年龄71±1.6岁）的外周血淋巴细胞用甲型流感病毒/台湾/1/86（H1N1）刺激7天，并检测其对甲型流感病毒/台湾、甲型流感病毒/上海（H3N2）和乙型流感病毒/苏联感染的自体靶细胞的裂解活性。与老年人相比，年轻人对甲型流感病毒H1N1和H3N2靶细胞表现出显著更高的甲型流感病毒交叉反应性CTL活性。在所有测试的效应细胞与靶细胞比例下均如此。观察到对乙型流感病毒/苏联感染的靶细胞或非自体甲型流感病毒/台湾感染的细胞的裂解作用可忽略不计。年轻成年人每毫升血液中回收的白细胞数量也显著高于老年献血者；然而，两组中CD45 +（普通白细胞抗原）、CD3 +（T细胞）、CD4 +（T辅助细胞）和CD8 +（T细胞毒性/抑制细胞）的百分比以及CD4 + /CD8 +比值相似。用单克隆抗体去除细胞表明效应细胞是CD8 + T细胞。年轻人和老年人的血清中和抗体（Nt Ab）滴度相似，且Nt Ab与CTL活性之间无相关性。这些结果表明老年人中甲型流感病毒特异性的主要组织相容性复合体I类限制性CTL活性降低。这种细胞介导的免疫功能缺陷可能导致该人群中流感病毒感染的发病率和死亡率增加。
