Serviço de Imunologia, Complexo Hospitalar Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia, Brazil.
J Immunol Res. 2019 Feb 28;2019:6574828. doi: 10.1155/2019/6574828. eCollection 2019.
The cytotoxic activities of CD8 T cells have been considered the main defense mechanism against the human T lymphotropic virus type 1 (HTLV-1). As with CD8 T cells, NK cells can perform cytotoxic degranulation with production of cytotoxic mediators, such as perforins and granzymes. NK cells are also responsible for antibody-dependent cellular cytotoxicity (ADCC) against infected cells, but few studies have evaluated the role of NK cells in HTLV-1 infection. The aim of this study was to characterize the subsets and measure the frequency of NK cells in HTLV-1 carriers (HC) and in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and correlate these findings with the proviral load and development of HAM/TSP. The diagnosis of HTLV-1 infection was performed with a detection antibody against viral antigens by ELISA and confirmed by Western blot. Phenotypic characterization of NK cells was performed by flow cytometry. The frequencies of CD56, CD56CD3, CD56CD16, and CD56 cells were decreased in HAM/TSP patients. The frequency of CD56CD3 cells was inversely correlated with proviral load in HC but not in HAM/TSP patients. HAM/TSP patients showed decreased frequency of CD56 and CD56 cells expressing CD16, the main receptor for ADCC. These data indicate that NK cells may play a key role in the control of HTLV-1 infection by preventing the progression of HC to HAM/TSP.
CD8 T 细胞的细胞毒性活性被认为是抵抗人类 T 淋巴细胞病毒 1 型（HTLV-1）的主要防御机制。与 CD8 T 细胞一样，NK 细胞可以通过产生细胞毒性介质（如穿孔素和颗粒酶）进行细胞毒性脱粒。NK 细胞还负责针对感染细胞的抗体依赖性细胞毒性（ADCC），但很少有研究评估 NK 细胞在 HTLV-1 感染中的作用。本研究旨在描述 NK 细胞亚群并测量 HTLV-1 携带者（HC）和 HTLV-1 相关脊髓病/热带痉挛性截瘫（HAM/TSP）患者 NK 细胞的频率，并将这些发现与前病毒载量和 HAM/TSP 的发展相关联。HTLV-1 感染的诊断通过 ELISA 检测针对病毒抗原的抗体进行，并通过 Western blot 进行确认。通过流式细胞术对 NK 细胞进行表型特征分析。在 HAM/TSP 患者中，CD56、CD56CD3、CD56CD16 和 CD56 细胞的频率降低。在 HC 中，CD56CD3 细胞的频率与前病毒载量呈负相关，但在 HAM/TSP 患者中则没有。HAM/TSP 患者中表达 CD16 的 CD56 和 CD56 细胞的频率降低，CD16 是 ADCC 的主要受体。这些数据表明，NK 细胞可能通过防止 HC 进展为 HAM/TSP 在控制 HTLV-1 感染中发挥关键作用。
