Qiu Shuangjian, Ye Shenglong, Tang Zhaoyou, Qian Shiguang, Li Lina
Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Zhonghua Yi Xue Za Zhi. 2002 Feb 25;82(4):253-6.
To investigate the feasibility of using hepatitis B virus surface antigen (HbsAg) as a tumor-associated antigen in immunogen therapy against tumor.
(1) Dendritic cells (DCs) were extracted from bone marrow of mice and cultured. Mature DCs were transfected with adenovirus vector highly expressing HBsAg and enhanced green fluorescence protein (EGFP) (DC-HBsAg). Eight C57BL/6J mice were immunized by intravenous injection of 1 x 10(6) DC-HBsAg. Seven days after, the immunization procedure was boosted by injection of the DC-HBsAg with the same dosage once more. Another eighteen mice were divided into 3 groups, 6 in each, to be injected with DC-EGFP (DCs transfected with 1 x 10(6) adenovector expressing only EGFP), 1 x 10(6) DCs, and PBS of the same volume as controls. One week after the second injection, subcutaneous injection of 7X105 mouse melanoma cells B16 or B16-HBsAg (B16 cells expressing HBsAg) was performed to each mouse. The size of tumor was measured every 2 - 3 days. When the tumor grew to the size of 2cm or caused ulcer the tumor-carrying mice were killed. The mice in the DC-HBsAg group that showed no tumorigenesis 30 days after inoculation of B16-HBsAg were re-inoculated with 7X105 B16-HBsAg. Three normal B6 mice of the same age and sex were used as controls. (2) Other patch of mice were divided into 4 groups and injected with DC-HBsAg, DC-EGFP, HBsAg (1 ug/mouse), and PBS in the same way as mentioned above. One week after the second injection at least 5 mice in each group were inoculated with 7X105 B16-HBsAg and 2 mice in each group were killed to have their serum anti-HbsAg titers examined.
(1) Seven days after inoculation of B16-HbsAg tumor began to grow in all mice in the three control groups. Tumor was found in 5 of the 8 mice in the DC-HBsA group and the other 3 mice in this group remained free of tumor. However, the size of tumor in these 5 mice was significantly smaller than thate in other groups (P < 0.01). B16-HBsAg was re-inoculated to the three mice that showed no tumor growth 30 days after the first inoculation of B16-HBsAg. However, still no tumor could be found in them. After inoculation of wild type melanoma cell B16 tumorigenesis was seen in the two immunization groups. (2) The titer of anti-HBsAg antibody induced by DC-HBsAg was obviously lower than that induced by recombinant HBsAg vaccine. However, the size of tumor in HBsAg group was obviously smaller than that in recombinant HBsAg group.
DC-HBsAg induces HBsAg-specific antitumor effect, stronger than that induced by recombinant HBsAg vaccine although the humoral immune response elicited by DC vaccine is much weaker that that induced by recombinant HBsAg vaccine. HBsAg can be used as a target antigen in immunogen therapy for treatment of cancer.
探讨将乙肝病毒表面抗原（HbsAg）作为肿瘤相关抗原用于肿瘤免疫原治疗的可行性。
（1）从小鼠骨髓中提取树突状细胞（DCs）并进行培养。用高表达乙肝表面抗原（HBsAg）和增强型绿色荧光蛋白（EGFP）的腺病毒载体转染成熟DCs（DC-HBsAg）。通过静脉注射1×10⁶个DC-HBsAg对8只C57BL/6J小鼠进行免疫。7天后，再次注射相同剂量的DC-HBsAg加强免疫程序。另外18只小鼠分为3组，每组6只，分别注射DC-EGFP（用1×10⁶个仅表达EGFP的腺病毒载体转染的DCs）、1×10⁶个DCs以及相同体积的PBS作为对照。第二次注射1周后，对每只小鼠皮下注射7×10⁵个小鼠黑色素瘤细胞B16或B16-HBsAg（表达HBsAg的B16细胞）。每2 - 3天测量肿瘤大小。当肿瘤长到2cm大小或引起溃疡时，处死荷瘤小鼠。接种B16-HBsAg 30天后未发生肿瘤的DC-HBsAg组小鼠，再次接种7×10⁵个B16-HBsAg。选取3只同龄同性别正常B6小鼠作为对照。（2）将另一批小鼠分为4组，按照上述相同方法分别注射DC-HBsAg、DC-EGFP、HBsAg（1μg/只）和PBS。第二次注射1周后，每组至少5只小鼠接种7×10⁵个B16-HBsAg，每组处死2只小鼠检测血清抗-HbsAg滴度。
（1）接种B16-HbsAg 7天后，3个对照组的所有小鼠肿瘤均开始生长。DC-HBsA组8只小鼠中有5只出现肿瘤，该组另外3只小鼠未出现肿瘤。然而，这5只小鼠的肿瘤大小明显小于其他组（P < 0.01）。对首次接种B16-HBsAg 30天后未出现肿瘤生长的3只小鼠再次接种B16-HBsAg。然而，它们仍然未出现肿瘤。接种野生型黑色素瘤细胞B16后，两个免疫组均出现肿瘤发生。（2）DC-HBsAg诱导产生的抗-HBsAg抗体滴度明显低于重组HBsAg疫苗诱导产生的滴度。然而，HBsAg组的肿瘤大小明显小于重组HBsAg组。
DC-HBsAg可诱导HBsAg特异性抗肿瘤效应，虽然DC疫苗引发的体液免疫反应比重组HBsAg疫苗弱得多，但比重组HBsAg疫苗诱导的效应更强。HBsAg可作为免疫原治疗癌症的靶抗原。
