Department of General Surgery, the Fourth Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
J Surg Res. 2013 Aug;183(2):900-6. doi: 10.1016/j.jss.2013.02.001. Epub 2013 Feb 24.
The tumor-draining lymph node (TDLN) is the critical and initial site of the immune decision made between activation and tolerance to tumor antigens. Tumor-reactive lymphadenopathy in TDLN has been observed for decades, but the profiles of immune regulation in these nodes remain unclear.
Both regulatory T cells (Tregs) and effector T cells were examined using 6 × 10(5) Hepa1-6 hepatocellular carcinoma cells implanted in footpads of syngeneic C57BL/6J mice, which formed TDLN. FOXP3(+) Tregs and CD8(+) T cells in TDLN were detected by immunohistochemical staining. The frequency of CD4(+)FOXP3(+) T cells and FOXP3 mRNA expression were determined by flow cytometry and real-time quantitative polymerase chain reaction. The interferon γ secretion ability of CD8(+) T cells in TDLN was measured by enzyme-linked immunospot technique.
There was significant expansion of Tregs and CD8(+) T cells in the tumor-draining popliteal lymph node compared with nondraining popliteal lymph node and spleen in the same mouse. Tregs were diffusely distributed in the CD8(+) T cell compartment. The CD8(+) T cells primed in TDLN showed a strong ability of interferon γ secretion via in vitro stimulation.
These findings support the notion that Tregs suppress CD8(+) T cells by secreting cytokines such as transforming growth factor β and interleukin 10, but do not make CD8(+) T cells lose function in the TDLN. Deletion of Tregs at the secondary lymphoid organs could be crucial for the establishment of a tumor-specific immunotherapy.
肿瘤引流淋巴结（TDLN）是在肿瘤抗原激活和耐受之间做出免疫决策的关键和初始部位。数十年来，人们一直观察到 TDLN 中的肿瘤反应性淋巴结病，但这些淋巴结中免疫调节的特征仍不清楚。
使用 6×10(5)个 Hepa1-6 肝癌细胞植入同种 C57BL/6J 小鼠的足底，形成 TDLN，检查调节性 T 细胞（Tregs）和效应 T 细胞。通过免疫组织化学染色检测 TDLN 中的 FOXP3(+)Tregs 和 CD8(+)T 细胞。通过流式细胞术和实时定量聚合酶链反应确定 CD4(+)FOXP3(+)T 细胞和 FOXP3 mRNA 表达的频率。通过酶联免疫斑点技术测量 TDLN 中 CD8(+)T 细胞的干扰素 γ 分泌能力。
与同一小鼠的非引流性腘淋巴结和脾脏相比，肿瘤引流性腘淋巴结中 Tregs 和 CD8(+)T 细胞明显扩增。Tregs 弥漫分布在 CD8(+)T 细胞区室中。在 TDLN 中激活的 CD8(+)T 细胞表现出通过体外刺激强烈分泌干扰素 γ 的能力。
这些发现支持 Tregs 通过分泌转化生长因子β和白细胞介素 10 等细胞因子抑制 CD8(+)T 细胞，但不会使 CD8(+)T 细胞在 TDLN 中失去功能的观点。在次级淋巴器官中删除 Tregs 对于建立肿瘤特异性免疫疗法可能至关重要。
