Development of lung cancer treatment strategy using dendritic cells expressing anti-angiogenic function

血管内皮生长因子具有阻碍血液中树突状细胞成熟的作用。本研究首次将可溶性VEGF受体基因导入树突状细胞，并尝试使树突状细胞产生与肿瘤相对抗的VEGF。腺病毒载体用于该基因转导。通过在培养基中添加GM-CSF和IL-4，从小鼠骨髓细胞分化树突状细胞。可溶性VEGF受体cDNA由野生型VEGF受体的胞外结构域和人IgG Fc部分组成。树突状细胞的基因导入效率与感染病毒的密度相关，并且在moi 50的具有感染细胞的培养基中证实了大量的可溶性VEGF受体。感染细胞培养上清可阻断VEGF诱导的血管内皮细胞DNA合成。VEGF的存在抑制了DC细胞的成熟，抑制了B7分子和MHC分子的表达，并降低了T细胞的增殖能力。另一方面，导入可溶性VEGF受体基因的树突状细胞促进了B7和MHC分子的表达，并维持了T细胞对VEGF的增殖能力。接着，使用α-半乳糖神经酰胺（α-GalCer）作为提高树突细胞的抗肿瘤活性的方法。α-GalCer通过树突状细胞上表达的MHC I类分子CD 1d呈递给NKT细胞。然后，将α-GalCer给予未成熟或成熟树突状细胞，并检查MHC I类、II类和CD 86的表达以及抗肿瘤效果。α-GalCer负载的树突状细胞对肿瘤的生长有明显的抑制作用，并延长了肿瘤的生存时间。

Vascular endothelial growth factor has an action that obstructs the maturity of the dendritic cell in blood. Then, soluble VEGF receptor gene was introduced into the dendritic cell first in this research, and making the dendritic cell that rivaled the tumor producing VEGF was tried. Adenovirus vector was used for this gene transduction. The dendritic cells were differentiated from the mouse marrow cells by addition of GM-CSF and IL-4 in the culture media. Soluble VEGF receptor cDNA was consisted in the extracellular domain of wild type VEGF receptor and human IgG Fc portion. The gene introduction efficiency to the dendritic cell correlated to the density of the infection virus, and considerable amount of soluble VEGF receptor was confirmed in the culture media with infected cells at moi 50. The culture supernatant of the infected cell obstructed DNA synthesis of vasucular endothelial cell by human VEGF. DC cells maturation is inhibited in the presence of VEGF, and the expression of the B7 molecule and the MHC molecule was suppressed both, and the proliferation potency of T cell has also decreased. On the other hand, the dendritic cell that introduced soluble VEGF receptor gene promoted the expression of B7 and the MHC molecule, and also maintained the proliferation potency of T cell against VEGF addition into medium. Next, alpha-galactosylceramide (a-GalCer) was used as a method of improving the antitumor activity of the dendritic cell. α-GalCer is presented in the NKT cell through MHC class I molecule, CD1d that express on the dendritic cell. Then, a-GalCer was administered to an immature or mature dendritic cell, and the expression of MHC class I, II, and CD86, and anti-tumor effect was examined. Dendritic cell pulsed with α-GalCer showed the significant suppression of tumor growth and improved the survival time.