Deng Meiju, Biao Ruojia, Jiang Meiqing, Fu Jiantao, Zhao Hongxin, Du Juan
Clinical Center for HIV/AIDS, Beijing Ditan Hospital, Capital Medical University, Beijing, 100015, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, 100015, China.
J Transl Med. 2025 May 26;23(1):584. doi: 10.1186/s12967-025-06591-3.
Human immunodeficiency virus type 1 (HIV-1) infection is associated with over-activation, which contributes to disease progression. Platelet-leukocyte aggregates play a critical role in HIV-1 infection. However, research on the characteristics of platelet-natural killer (NK) cell aggregates in HIV-infected individuals still has certain limitations.
Platelet-NK cell aggregates in the peripheral blood of participants were detected by flow cytometry and confirmed by imaging flow cytometry. Platelet activation was evaluated by CD62P expression. The expression of various activating and inhibitory receptors, markers of apoptosis, lipid droplets, interferon-gamma (IFN-γ), Granzyme B, and Perforin in platelet-NK cell aggregates were assessed. The signaling lymphocyte activating molecule (SLAM) family receptors in both platelets and NK cells and the levels of phosphorylation signals in NK cells were respectively measured through flow cytometry.
In this study, we observed an increase in platelet-NK cell aggregates that were negatively correlated with CD4 count, a prognostic marker for HIV-1 disease progression. Furthermore, platelet activation was inversely associated with both HIV-1 disease progression and the platelet-NK cell aggregates. However, antiretroviral therapy (ART) couldn't restore the levels of these aggregates or platelet activation. Compared to platelet-free NK cells, platelet-NK cell aggregates exhibited over-activation (CD69) and exhaustion phenotypes (CD39, LAG-3, PD-1), increased levels of apoptosis (Annexin V and CD95) and lipid droplets (Bodipy 493/503 and LipidTOX). Furthermore, NK cells' cytokine secretion (IFN-γ) and cytotoxic function (Granzyme B and Perforin) within the aggregates were declined. Screening results of SLAM receptors in NK cells and platelets suggested that platelets may transmit signals to NK cells via SLAMF5. Moreover, elevated levels of p-Fyn, p-PLC-γ2, p-SHP-1, and p-SHP-2 denoted disturbances in the downstream signals of the SLAM family within platelet-NK cell aggregates.
Our study indicates that platelet-NK cell aggregates exhibit characteristics of over-activation and dysfunction during HIV-1 infection. Hyperactivated platelets and the formation of platelet-NK cell aggregates contribute to the HIV-1 disease progression and the inflammation of the immune system. These findings may implicate potential targets of overactivated platelets for HIV-1 disease progression.
1型人类免疫缺陷病毒（HIV-1）感染与过度激活相关，这会促进疾病进展。血小板-白细胞聚集体在HIV-1感染中起关键作用。然而，关于HIV感染个体中血小板-自然杀伤（NK）细胞聚集体特征的研究仍存在一定局限性。
通过流式细胞术检测参与者外周血中的血小板-NK细胞聚集体，并通过成像流式细胞术进行确认。通过CD62P表达评估血小板活化。评估血小板-NK细胞聚集体中各种激活和抑制受体、凋亡标志物、脂滴、干扰素-γ（IFN-γ）、颗粒酶B和穿孔素的表达。通过流式细胞术分别检测血小板和NK细胞中的信号淋巴细胞激活分子（SLAM）家族受体以及NK细胞中的磷酸化信号水平。
在本研究中，我们观察到血小板-NK细胞聚集体增加，且与HIV-1疾病进展的预后标志物CD4计数呈负相关。此外，血小板活化与HIV-1疾病进展以及血小板-NK细胞聚集体均呈负相关。然而，抗逆转录病毒疗法（ART）无法恢复这些聚集体的水平或血小板活化。与无血小板的NK细胞相比，血小板-NK细胞聚集体表现出过度激活（CD69）和耗竭表型（CD39、LAG-3、PD-1），凋亡（膜联蛋白V和CD95）和脂滴（Bodipy 493/503和LipidTOX）水平升高。此外，聚集体内NK细胞的细胞因子分泌（IFN-γ）和细胞毒性功能（颗粒酶B和穿孔素）下降。NK细胞和血小板中SLAM受体的筛选结果表明，血小板可能通过SLAMF5向NK细胞传递信号。此外，血小板-NK细胞聚集体中p-Fyn、p-PLC-γ2、p-SHP-1和p-SHP-2水平升高表明SLAM家族下游信号存在紊乱。
我们的研究表明，在HIV-1感染期间，血小板-NK细胞聚集体表现出过度激活和功能障碍的特征。过度活化的血小板和血小板-NK细胞聚集体的形成有助于HIV-1疾病进展和免疫系统炎症。这些发现可能暗示过度活化血小板在HIV-1疾病进展中的潜在靶点。
