Repeated DNA Vaccination Induced Neonatal Tolerance against Escherichia. coli. Beta-Galactosidase in Immune-Competent Mice

重覆DNA疫苗注射能誘發免疫力正常的小黑鼠對大腸桿菌半乳糖酶産生免疫耐受性

劉安邦(An-Bang Liu) ； 戴國峰(Kuo-Feng Tai) ； 林欣榮(Shinn-Zong Lin)

《慈濟醫學雜誌》 17卷2期 (2005/02) Pp. 75-81

https://doi.org/10.6440/TZUCMJ.200502.0075

摘要

目的：本研究的目的是要探討以重覆DNA疫苗注射能否誘發免疫力正常的小黑鼠對大腸桿菌半乳糖酶產生新生兒免疫耐受性。材料與方法：我們取兩組初生的C57BL/6小黑鼠，每組六隻，一組在其後頸皮下注射2微克(μg)溶於無菌磷酸鹽緩衝溶液不含細菌內毒素的質體－pCBLacZ，另一組經由肛門注射等量pCBLacZ。每一隻新生小鼠在出生後第二天接受注射，以後每隔七天注射一次，一共注射六次，在最後一次注射後七天，所有小鼠都在左前經骨肌注射50微克的pCBLacZ，這個質體將表達大腸桿菌半乳糖酶以誘發局部的免疫反應。對照組則有六隻未曾接受過任何處置的六週大C57BL/6成鼠在左前脛骨肌接受50μg pCBLacZ的肌肉注射。結果：我們在注射後第六天檢視小鼠的肌肉切片，發現呈現半乳糖酶活性的肌細胞數目在對照組平均為16.2，經皮下注射DNA疫苗者為0，由肛門注射為168.2，以Likelihood ratio test分析得P值為0.0001，在肛門注射組中有兩隻小鼠分別有409和513個肌細胞表達半乳糖酣；以ELISA分析三組血中抗半乳糖酶IgG含量，則發現接受肛門注射的小鼠其血中IgG要比其它兩組來得低。結論：在新生小鼠給予重覆DNA疫苗注射能引發免疫力正常的小鼠對異蛋白產生免疫耐受性，同時疫苗的投予方式會決定耐受性的產生與否。

關鍵字

轉植基因 ； 新生兒免疫耐受性 ； DNA疫苗

並列摘要

Objectives: To induce neonatal immune tolerance in immune competent animals by repeated DNA vaccination. Materials and Methods: We used two groups of neonatal immune competent mice, C57BL/6, six in each. Mice in one study group received subcutaneous injection of 2 μg of endotoxin-free plasmid, pCBLacZ, at the posterior neck area. Concentration of the plasmid was 0.5 mg/mL. This plasmid encoded a potent immunogen, Escherichia coil beta-galactosidase. Mice in the other study group received intrarectal injection of same amount of pCBLacZ. All the animals received injection at the second day of birth and 5 consecutive injections of the same dose of pCBLacZ at an interval of 7 days. Seven days after the last shoot, the mice received an intramuscular injection of 50 μg of endotoxin-free pCBLacZ at a concentration of 2 mg/mL at the left anterior tibialis. We used 6 naive adult C57BL/6 as the control. These animals received an intramuscular injection of 50 μg of pCBLacZ at the left anterior tibialis at age of 42 days. Results: We examined the expression of beta-galactosidase in muscle fibers 6 days after the last intramuscular injection. The average numbers of fibers expressing beta-galactosidase was 168.2 in the mice receiving intrarectal immunization as compared with 0 in the mice receiving subcutaneous injection and 16.2 in their little mates. (p=0.001 by likelihood ratio test). There were two mice got 409 and 513 blue fibers respectively. Serum IgG against the beta-galactosidase was lower in the animals receiving intrarectal injection as compared with the mice in the other two groups by nonparametric Mann-Whitney test. Conclusions: Repeated DNA vaccination in the neonatal stage can induce immune tolerance against a potent immunogen in the immune competent animals. The ways of administration determine the success of tolerance induction.

並列關鍵字

transgene ； neonatal tolerance ； DNA vaccination