Zhao Liang, Wang Huifang, Zhang Yu, Shi Yanze, Zhou Chunbao, Yu Minrui, Wang Yanhu, Zhang Liping, Xu Zheng, Zhang Ziying, Gao Lingyu, Zhang Jiyuan, Yang Baopeng, Huang Huihuang, Wang Fu-Sheng
Medical School of Chinese PLA, Beijing, China; Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China.
Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China; Senior Department of Infectious Diseases and Hepatology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Mol Immunol. 2024 Sep;173:40-52. doi: 10.1016/j.molimm.2024.07.003. Epub 2024 Jul 24.
HIV-1 chronically infects host CD4 T lymphocytes and further affects a variety of immune cells, including CD8 T cells. In our previous study, by analyzing unbiased high-dimensional single-cell RNA-seq data (scRNA-seq), we found that the frequency of GZMKCD8 T cells expressing granzyme K (GZMK) was increased in people living with HIV-1 (PLWHs). However, the phenotypic and functional characteristics of these cells in chronic HIV-1 infection and their correlation with disease are not well understood. In this study, we conducted a comprehensive analysis of scRNA-seq and matched T-cell receptor repertoire (TCR) sequencing data to delve into the characterizations of GZMKCD8 T cells, which was further validated by flow cytometry. We observed heterogeneity within the GZMKCD8 T cells, which could be further subdivided into a GZMKGZMB subset and a GZMKGZMB subset, with the latter being significantly enriched in PLWHs. The GZMKGZMB cells are a unique subset within CD8 T cells, characterized by high proliferation, activation, inflammatory response, clone transition, etc., and are one of the differentiation endpoints by pseudotemporal analysis of CD8+αβ T cells. Despite being predominantly composed of effector memory T cells (Tem), similar to the GZMKGZMB subset, the GZMKGZMB subset exhibits differentiation at a later stage than the GZMKGZMB subset. We also observed that the frequency/count of GZMKGZMBCD8 T cells was negatively correlated with CD4/CD8 ratio, and positively correlated with HIV DNA, IP-10, and MIG levels in PLWHs. In vitro experiments demonstrate that GZMK can potentiate the stimulatory effects of lipopolysaccharide (LPS) on THP-1 macrophages via the TLR-4 pathway, significantly enhancing the secretion of IP-10, MIG, and MCP-1, as well as increasing the proportion of TNF-α cells. In conclusion, in PLWHs, GZMKGZMBCD8 T cells are a highly reactive and inflammatory-inducing subset that may be associated with systemic inflammation.
人类免疫缺陷病毒1型（HIV-1）长期感染宿主CD4 T淋巴细胞，并进一步影响包括CD8 T细胞在内的多种免疫细胞。在我们之前的研究中，通过分析无偏差的高维单细胞RNA测序数据（scRNA-seq），我们发现表达颗粒酶K（GZMK）的GZMK⁺CD8 T细胞在HIV-1感染者（PLWH）中的频率增加。然而，这些细胞在慢性HIV-1感染中的表型和功能特征及其与疾病的相关性尚不清楚。在本研究中，我们对scRNA-seq和匹配的T细胞受体库（TCR）测序数据进行了全面分析，以深入研究GZMK⁺CD8 T细胞的特征，并通过流式细胞术进一步验证。我们观察到GZMK⁺CD8 T细胞内存在异质性，可进一步细分为GZMK⁺GZMB⁻亚群和GZMK⁺GZMB⁺亚群，后者在PLWH中显著富集。GZMK⁺GZMB⁺细胞是CD8 T细胞内的一个独特亚群，其特征在于高增殖、激活、炎症反应、克隆转变等，并且是通过对CD8⁺αβ T细胞进行伪时间分析得出的分化终点之一。尽管主要由效应记忆T细胞（Tem）组成，与GZMK⁺GZMB⁻亚群相似，但GZMK⁺GZMB⁻亚群的分化阶段比GZMK⁺GZMB⁺亚群晚。我们还观察到，PLWH中GZMK⁺GZMB⁺CD8 T细胞的频率/数量与CD4/CD8比值呈负相关，与HIV DNA、IP-10和MIG水平呈正相关。体外实验表明，GZMK可通过TLR-4途径增强脂多糖（LPS）对THP-1巨噬细胞的刺激作用，显著增强IP-10、MIG和MCP-1的分泌，并增加TNF-α细胞的比例。总之，在PLWH中，GZMK⁺GZMB⁺CD8 T细胞是一个高反应性且诱导炎症的亚群，可能与全身炎症有关。
