Liyanage Udaya K, Goedegebuure Peter S, Moore Todd T, Viehl Carsten T, Moo-Young Tricia A, Larson Justin W, Frey Daniel M, Ehlers Jesmin P, Eberlein Timothy J, Linehan David C
Laboratory for Biologic Cancer Therapy, Department of Surgery and Alvin J. Siteman Cancer Center, Washington University School of Medicine, Saint Louis, MO, USA.
J Immunother. 2006 Jul-Aug;29(4):416-24. doi: 10.1097/01.cji.0000205644.43735.4e.
We reported earlier that patients with breast or pancreas cancer have an increased prevalence of regulatory T cells (Treg) in the blood and tumor draining lymph nodes (TDLNs) compared with healthy individuals. In the current study, we tested the hypothesis that tumor cells promote the prevalence of Treg. The transforming growth factor-beta (TGF-beta) secreting murine pancreas adenocarcinoma, Pan02 cell line was injected into syngeneic C57BL/6 mice and the prevalence of Treg in the TDLNs and tumor spleen was measured weekly. Compared with control mice, the prevalence of CD25+ CD4+ cells in TDLNs and in tumor spleen increased with tumor growth. Analysis of these CD25+ CD4+ T cells in vitro confirmed expression of the Treg marker, Foxp3. In addition, their functional activity resembled that of Treg, as evidenced by a poor proliferative capacity; suppression of proliferation of CD25- CD4 or CD8T cells and inhibition of interferon-gamma release by CD25- CD4+ T cells. Reconstitution of Pan02-bearing Rag-/- mice with naive syngeneic CD25- CD4+ T cells induced CD25+ CD4+ Foxp3+ T cells in TDLNs, but not in the spleen. In contrast, Foxp3 was not detected in unreconstituted Pan02-bearing Rag-/- mice, or reconstituted mice bearing a TGF-beta-negative esophageal tumor. Furthermore, administration of neutralizing anti-TGF-beta antibody blocked the induction of Foxp3 in reconstituted Pan02-bearing Rag-/- mice. These results mimic earlier in vitro studies showing induction of Foxp3 through CD3 plus CD28 stimulation in the presence of TGF-beta. We conclude that Pan02 tumor promotes the prevalence of Treg, in part through the secretion of TGF-beta, which may result in immune evasion.
我们之前报道过，与健康个体相比，乳腺癌或胰腺癌患者血液及肿瘤引流淋巴结（TDLN）中调节性T细胞（Treg）的患病率有所增加。在本研究中，我们验证了肿瘤细胞会促进Treg患病率这一假说。将分泌转化生长因子-β（TGF-β）的小鼠胰腺腺癌Pan02细胞系注射到同基因C57BL/6小鼠体内，并每周测量TDLN和肿瘤脾脏中Treg的患病率。与对照小鼠相比，TDLN和肿瘤脾脏中CD25⁺CD4⁺细胞的患病率随肿瘤生长而增加。对这些CD25⁺CD4⁺T细胞进行体外分析，证实了Treg标志物Foxp3的表达。此外，它们的功能活性类似于Treg，表现为增殖能力较差；抑制CD25⁻CD4或CD8 T细胞的增殖以及抑制CD25⁻CD4⁺T细胞释放干扰素-γ。用同基因幼稚CD25⁻CD4⁺T细胞重建荷Pan02的Rag⁻/⁻小鼠，可在TDLN中诱导出CD25⁺CD4⁺Foxp3⁺T细胞，但在脾脏中则不然。相比之下，在未重建的荷Pan02的Rag⁻/⁻小鼠或重建的荷TGF-β阴性食管肿瘤的小鼠中未检测到Foxp3。此外，给予中和性抗TGF-β抗体可阻断重建的荷Pan02的Rag⁻/⁻小鼠中Foxp3的诱导。这些结果与早期的体外研究结果相似，即在存在TGF-β的情况下，通过CD3加CD28刺激可诱导Foxp3。我们得出结论，Pan02肿瘤部分通过分泌TGF-β促进Treg的患病率，这可能导致免疫逃逸。
