Abdo Eiman, Ismail Mohammad A, Al Hadidi Sabal, Al-Mrahleh Mairvat, Saleh Tareq, Zihlif Malik, Ababneh Nidaa A
Department of Pharmacology, School of Medicine, University of Jordan, Amman, Jordan.
Cell Therapy Center, The University of Jordan, Amman, Jordan.
PLoS One. 2025 Jan 30;20(1):e0311615. doi: 10.1371/journal.pone.0311615. eCollection 2025.
Hypoxia in tumor cells is linked to increased drug resistance and more aggressive behavior. In pancreatic cancer, the tumor microenvironment is notably hypoxic and exhibits strong immunosuppressive properties. Given that immunotherapy is now approved for pancreatic cancer treatment, further understanding of how pancreatic tumor cell hypoxia influences T-cell cytotoxicityis essential.
This study examined how hypoxia affects the interaction between pancreatic tumor cells (PANC-1) and cytotoxic CD8+ T-cells.
Pancreatic tumor cells (PANC-1) were exposed to 20 cycles of chronic hypoxic conditions, each for 72 hours, followed by a re-oxygenation period for 24 hours. On cycles 10 and 20, PANC-1 conditioned media (CM) was harvested, and the hypoxic PANC-1 cells were co-cultured with either the activated cytotoxic CD8+ T-cells or with CD8+ T-cells CM. CD8+ T-cells CM was collected after five days of cell activation using anti-CD3/CD28 antibodies and interleukin-2 (IL-2). CD8+ T-cells were activated for 72 hours and then cultured with the hypoxic PANC-1 CM.
Hypoxic PANC-1 cells showed significant resistance to the lytic effect of either CD8+ T-cells co-culture or CD8+ T-cells CM treatment compared to normoxic PANC-1 cells. A significant decrease in TNF-α and IFN-γ levels was also detected. Additionally, a significant increase in IL-6, p53 and TNF-α gene expression levels was observed in PANC-1 cells treated with CD8+ T-cells CM. Moreover, IL-6 gene expression level showed a significant difference between hypoxic and normoxic PANC-1 cells. CD8+ T-cell proliferation and cytokines production were significantly higher in cells co-cultured with PANC-1 CM. However, no significant differences were observed after treatment with either hypoxic or normoxic PANC-1 CM.
Hypoxia decreases PANC-1 cells' sensitivity to cytotoxic CD8+ T-cells. Reduced tumor cell susceptibility to CD8+ T-cells was associated with increased IL-6 expression and reduced TNF-α and IFN-γ levels. Thus, cytokine dysregulation might contribute to the hypoxia-mediated resistance of pancreatic tumor cells to CD8+ T-cells.
肿瘤细胞中的缺氧与耐药性增加和更具侵袭性的行为有关。在胰腺癌中，肿瘤微环境明显缺氧，并表现出强大的免疫抑制特性。鉴于免疫疗法现已获批用于胰腺癌治疗，进一步了解胰腺肿瘤细胞缺氧如何影响T细胞细胞毒性至关重要。
本研究探讨缺氧如何影响胰腺肿瘤细胞（PANC-1）与细胞毒性CD8+T细胞之间的相互作用。
将胰腺肿瘤细胞（PANC-1）暴露于20个周期的慢性缺氧条件下，每个周期72小时，随后进行24小时的复氧期。在第10和20个周期时，收集PANC-1条件培养基（CM），并将缺氧的PANC-1细胞与活化的细胞毒性CD8+T细胞或CD8+T细胞CM共培养。使用抗CD3/CD28抗体和白细胞介素-2（IL-2）激活细胞5天后收集CD8+T细胞CM。将CD8+T细胞激活72小时，然后与缺氧的PANC-1 CM共培养。
与常氧PANC-1细胞相比，缺氧的PANC-1细胞对CD8+T细胞共培养或CD8+T细胞CM处理的裂解作用表现出显著抗性。还检测到TNF-α和IFN-γ水平显著降低。此外，在用CD8+T细胞CM处理的PANC-1细胞中，观察到IL-6、p53和TNF-α基因表达水平显著增加。此外，IL-6基因表达水平在缺氧和常氧PANC-1细胞之间存在显著差异。与PANC-1 CM共培养的细胞中，CD8+T细胞增殖和细胞因子产生显著更高。然而，用缺氧或常氧PANC-1 CM处理后未观察到显著差异。
缺氧降低了PANC-1细胞对细胞毒性CD8+T细胞的敏感性。肿瘤细胞对CD8+T细胞的敏感性降低与IL-6表达增加以及TNF-α和IFN-γ水平降低有关。因此，细胞因子失调可能导致胰腺肿瘤细胞对CD8+T细胞的缺氧介导抗性。
