Li Ling, Zhao Manzhi, van Meurs Marjan, Brouwers-Haspels Inge, den Dekker Renske J H, Wilmsen Merel E P, Grashof Dwin G B, van de Werken Harmen J G, Rao Shringar, Rokx Casper, Mueller Yvonne M, Katsikis Peter D
Department of Immunology, Erasmus University Medical Center, Rotterdam, Netherlands.
Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands.
Front Immunol. 2025 Jan 14;15:1509874. doi: 10.3389/fimmu.2024.1509874. eCollection 2024.
Bryostatin-1, a potent agonist of the protein kinase C, has been studied for HIV and cancer therapies. In HIV research, it has shown anti-HIV effects during acute infection and reactivation of latent HIV in chronic infection. As effective CD8+ T cell responses are essential for eliminating reactivated virus and achieving a cure, it is important to investigate how bryostatin-1 affects HIV-specific CD8+ T cells. HIV-specific CD8+ T cells often become exhausted, showing reduced proliferative potential and impaired cytokine production, a dysfunction also observed in cancer. Therefore, we further investigated how bryostatin-1 directly impacts exhausted CD8+ T cells.
PBMCs from people with HIV (PWH) were treated with bryostatin-1 and tracked with proliferation dye for cell expansion. One day 6, HIV-specific CD8+ T cells were detected by tetramers staining and examined by flow cytometry. By utilizing an established murine T cell exhaustion system, changes in inhibitory receptors, transcription factors, cytokine production and killing capacity of bryostatin-1 treated exhausted CD8+ T cells were determined by flow cytometry. RNA-seq analysis was performed to study transcriptional changes in these cells.
We found that bryostatin-1 improved the expansion and decreased PD-1 expression of HIV-specific CD8+ T cells. Bryostatin-1 enhanced the functionality and proliferation while decreasing inhibitory receptor expression of generated exhausted CD8+ T cells. Bryostatin-1 upregulated TCF-1 and decreased TOX expression. These changes were confirmed through RNA-seq analysis. RNA-seq revealed that mitogen-activated protein kinases (MAPK) 11 was significantly downregulated in exhausted CD8+ T cells, however, it greatly upregulated after bryostatin-1 treatment. Inhibition of MAPK11 in bryostatin-1-treated cells blocked the increased proliferation and IFN-γ production induced by bryostatin-1, but did not affect other bryostatin-1 induced effects, such as the reduction of inhibitory receptors.
Our data demonstrate that bryostatin-1 induces a MAPK 11-dependent improvement in the proliferative and functional capacity of exhausted T cells. This study provides a rationale for bryostatin-1's potential to help eradicate the HIV reservoir during treatment, and it may also contribute to cancer immunotherapy by functionally improving exhausted CD8+ T cells.
苔藓抑素-1是一种蛋白激酶C的强效激动剂，已被用于艾滋病和癌症治疗的研究。在艾滋病研究中，它在急性感染期间显示出抗艾滋病毒的作用，并能使慢性感染中潜伏的艾滋病毒重新激活。由于有效的CD8+ T细胞反应对于消除重新激活的病毒并实现治愈至关重要，因此研究苔藓抑素-1如何影响艾滋病毒特异性CD8+ T细胞很重要。艾滋病毒特异性CD8+ T细胞常常会耗竭，表现出增殖潜力降低和细胞因子产生受损，这种功能障碍在癌症中也有观察到。因此，我们进一步研究了苔藓抑素-1如何直接影响耗竭的CD8+ T细胞。
用苔藓抑素-1处理来自艾滋病毒感染者（PWH）的外周血单核细胞（PBMC），并用增殖染料追踪细胞扩增情况。在第6天，通过四聚体染色检测艾滋病毒特异性CD8+ T细胞，并用流式细胞术进行检测。利用已建立的小鼠T细胞耗竭系统，通过流式细胞术确定苔藓抑素-1处理的耗竭CD8+ T细胞在抑制性受体、转录因子、细胞因子产生和杀伤能力方面的变化。进行RNA测序分析以研究这些细胞中的转录变化。
我们发现苔藓抑素-1改善了艾滋病毒特异性CD8+ T细胞的扩增并降低了PD-1的表达。苔藓抑素-1增强了产生的耗竭CD8+ T细胞的功能和增殖能力，同时降低了抑制性受体的表达。苔藓抑素-1上调了TCF-1并降低了TOX的表达。这些变化通过RNA测序分析得到了证实。RNA测序显示，丝裂原活化蛋白激酶（MAPK）11在耗竭的CD8+ T细胞中显著下调，但在苔藓抑素-1处理后大幅上调。在苔藓抑素-1处理的细胞中抑制MAPK11可阻断苔藓抑素-1诱导的增殖增加和IFN-γ产生，但不影响苔藓抑素-1诱导的其他效应，如抑制性受体的减少。
我们的数据表明，苔藓抑素-1可诱导耗竭T细胞的增殖和功能能力以MAPK 11依赖的方式得到改善。这项研究为苔藓抑素-1在治疗期间帮助根除艾滋病毒储存库的潜力提供了理论依据，并且它可能还通过在功能上改善耗竭的CD8+ T细胞对癌症免疫治疗做出贡献。
