Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Inmunoquímica I, Mexico City, Mexico.
Laboratory of Immunobiology and Genetics, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico.
J Immunol Res. 2021 Apr 27;2021:5517856. doi: 10.1155/2021/5517856. eCollection 2021.
The mechanisms underlying the immunopathology of tuberculous meningitis (TBM), the most severe clinical form of extrapulmonary tuberculosis (TB), are not understood. It is currently believed that the spread of (Mtb) from the lung is an early event that occurs before the establishment of adaptive immunity. Hence, several innate immune mechanisms may participate in the containment of Mtb infection and prevent extrapulmonary disease manifestations. Natural killer (NK) cells participate in defensive processes that distinguish latent TB infection (LTBI) from active pulmonary TB (PTB). However, their role in TBM is unknown. Here, we performed a cross-sectional analysis of circulating NK cellCID="C008" value="s" phenotype in a prospective cohort of TBM patients ( = 10) using flow cytometry. Also, we addressed the responses of memory-like NK cell subpopulations to the contact with Mtb antigens . Finally, we determined plasma levels of soluble NKG2D receptor ligands in our cohort of TBM patients by enzyme-linked immunosorbent assay (ELISA). Our comparative groups consisted of individuals with LTBI ( = 11) and PTB ( = 27) patients. We found that NK cells from TBM patients showed lower absolute frequencies, higher CD69 expression, and poor expansion of the CD45RO memory-like subpopulation upon Mtb exposure compared to LTBI individuals. In addition, a reduction in the frequency of CD56CD16 NK cells characterized TBM patients but not LTBI or PTB subjects. Our study expands on earlier reports about the role of NK cells in TBM showing a reduced frequency of cytokine-producing cells compared to LTBI and PTB.
结核性脑膜炎(TBM)是最严重的肺外结核病(TB)临床形式,其发病机制尚不清楚。目前认为,结核分枝杆菌(Mtb)从肺部扩散是发生在适应性免疫建立之前的早期事件。因此,几种先天免疫机制可能参与了 Mtb 感染的控制,并防止了肺外疾病的表现。自然杀伤(NK)细胞参与了区分潜伏性结核病感染(LTBI)和活动性肺结核(PTB)的防御过程。然而,它们在 TBM 中的作用尚不清楚。在这里,我们通过流式细胞术对 TBM 患者(n=10)的前瞻性队列进行了循环 NK 细胞表型的横断面分析。此外,我们还研究了记忆样 NK 细胞亚群对 Mtb 抗原接触的反应。最后,我们通过酶联免疫吸附试验(ELISA)测定了我们的 TBM 患者队列中的可溶性 NKG2D 受体配体的血浆水平。我们的对照组包括 LTBI 个体(n=11)和 PTB 患者(n=27)。我们发现,与 LTBI 个体相比,TBM 患者的 NK 细胞绝对频率较低,CD69 表达较高,CD45RO 记忆样亚群的扩增能力较差,在接触 Mtb 后表现出这种情况。此外,CD56CD16 NK 细胞频率的降低是 TBM 患者的特征,但不是 LTBI 或 PTB 患者的特征。我们的研究扩展了早期关于 NK 细胞在 TBM 中作用的报告,与 LTBI 和 PTB 相比,TBM 患者产生细胞因子的细胞频率降低。