PO.IM02.02 · 免疫学
婴儿致命性发育性肿瘤中T细胞功能障碍与免疫冷微环境的驱动因素及机制
Driver and mechanism of t-cell dysfunction and immune cold microenvironment in deadly developmental tumor in infants
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
神经母细胞瘤（NB）是一种常见的儿童颅外恶性肿瘤，其特征为免疫学上的"冷"肿瘤微环境（TME），但其免疫逃逸的潜在机制仍知之甚少。在此，我们发现Retinal Degeneration 3（RD3）在NB进展过程中塑造宿主免疫和T细胞命运方面具有新的免疫调节作用。利用免疫健全的小鼠模型，包括神经嵴细胞（NCC）特异性RD3敲除（RD3⁻/⁻）、ALK磷酸化模拟突变（ALKF1174L敲入）或RD3⁻/⁻ ALKF1174L（侵袭性NB表型），我们证明RD3缺失并不损害胸腺T细胞发育，但深刻改变了外周T细胞的成熟和活化。RD3缺陷小鼠表现出CD3⁺ T细胞胸腺定向增强、TCR重排增加以及CD8⁺细胞毒性T淋巴细胞（CTL）成熟升高，而CD4⁺辅助性T细胞发育则明显受到抑制。在荷NB的RD3⁻/⁻小鼠中，我们观察到效应T细胞群体的肿瘤驱动性重编程，CD8⁺ CTL增加而CD4⁺活化减少，表明存在偏斜的免疫反应。脾脏微环境显示TCR编程细胞强劲归巢，但CD4⁺ T细胞活化受到阻断。野生型对照维持平衡的T细胞活化和效应细胞组成，凸显了RD3缺陷所诱导的免疫迂回。多重免疫荧光突出显示CD4⁺和CD8⁺效应T细胞耗竭、活化标志物（CD44、GITR）减少以及耗竭标志物CD244.2升高。固有免疫区室同样受损，CD206⁺、CD86⁺和STING⁺群体减少，反映抗原呈递受损。值得注意的是，RD3⁻/⁻肿瘤通过CD73/CD39/A2AR轴表现出增强的腺苷能抑制，建立了免疫活化的代谢屏障。这些前所未有的发现揭示RD3缺失是NB中免疫崩溃的核心协调者，促进T细胞耗竭、抑制抗原呈递并培育代谢受抑的TME。本研究为肿瘤内在免疫逃逸提供了机制性见解，并为恢复NB免疫功能的治疗策略奠定了基础。
资助：Department of Defense CA-210339；OCAST-HR19-04；NIH-P20GM103639；并得到P30CA225520和P30GM154635的支持。
查看英文原文 English abstract
Neuroblastoma (NB), a prevalent extracranial pediatric malignancy, is characterized by an immunologically “cold” tumor microenvironment (TME), yet the mechanisms underlying its immune evasion remain poorly understood. Here, we identify a novel immunoregulatory role for Retinal Degeneration 3 (RD3) in shaping host immunity and T-cell fate during NB progression. Using immune-competent mouse models, neural crest cell (NCC)-specific RD3 knockout (RD3 ⁻/⁻ ), ALK phosphor-mimetic mutated ( ALKF1174L knock-in), or RD3 ⁻/⁻ ALKF1174L (aggressive NB phenotype), we demonstrate that RD3-loss does not impair thymic T-cell development, but profoundly alters peripheral T-cell maturation and activation. RD3-deficient mice exhibit enhanced thymic commitment of CD3⁺ T-cells, increased TCR rearrangement, and elevated CD8⁺ cytotoxic T lymphocyte (CTL) maturation, while CD4⁺ helper T-cell development is markedly suppressed. In NB-bearing RD3 ⁻/⁻ mice, we observed tumor-driven reprogramming of effector T-cell populations, with increased CD8⁺ CTLs and diminished CD4⁺ activation, indicating a skewed immune response. Splenic microenvironment revealed robust homing of TCR-programmed cells but a blockade in CD4⁺ T-cell activation. Wild-type controls maintain balanced T-cell activation and effector composition, underscoring the immune detour induced by RD3 deficiency. Multiplex immunofluorescence highlights a depletion of CD4⁺ and CD8⁺ effector T-cells, reduced activation markers (CD44, GITR), and elevated exhaustion marker CD244.2. Innate immune compartments are similarly compromised, with diminished CD206⁺, CD86⁺, and STING⁺ populations, reflecting impaired antigen presentation. Notably, RD3 ⁻/⁻ tumors exhibit heightened adenosinergic suppression via the CD73/CD39/A2AR axis, establishing a metabolic barrier to immune activation. New to science, these findings reveal RD3-loss as a central orchestrator of immune collapse in NB, promoting T-cell exhaustion, suppressing antigen presentation, and fostering a metabolically suppressed TME. This study provides mechanistic insight into tumor-intrinsic immune evasion and lays the groundwork for therapeutic strategies to restore immune competence in NB.
Funding: Department of Defense CA-210339; OCAST-HR19-04; NIH-P20GM103639; and supported by P30CA225520 and P30GM154635.
利益披露 Disclosure
P. Subramanian, None..
S. Mohanvelu, None..
S. Aravindan, None..
S. Salim, None..
S. Narayanan, None..
N. Aravindan, None.