Anti-CTLA4 scFv, a Single-Chain Antibody, Can Prolong Expression of Escherichia. coli. beta-Galactosidase in Immune-Competent Mice

單鏈抗體anti-CTLA4-scFv能延長大腸桿菌半乳糖酶在免疫力正常的小黑鼠體內表達

劉安邦(An-Bang Liu) ； 羅博倫(Steve R. Roffler)

《慈濟醫學雜誌》 16卷1期 (2004/02) Pp. 25-31

https://doi.org/10.6440/TZUCMJ.200402.0025

摘要

目的:本研究之目的是要探討以基因轉植的方法在肌肉細胞表達毒殺T細胞相關第四抗原單鍵抗體-anti-CTLA4scFv以達到誘發免疫耐受性可能。材料與方法:我們將九週大且具正常免疫力的小黑鼠，C58/L6分成兩組每組十隻，對照組在其左前脛骨注射以溶於磷酸鹽緩衝溶液不含細菌內毒素的質體-pCBLacZ，DNA的濃度為1mg/mL，注射劑量為50微升(μL)，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。實驗組則除了注射pCBLacZ外還注射相同濃度相同劑量的另一質體-p4F10-eB7, 這個質體可以在肌細胞膜表達anti-CTLA4 scFv。結果:我們在注射後第六和第十二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在六天時，對照組平均為2.2，以無母體分析Mann-whitney test 得p值為0.015；實驗組為43.6；在第十二天時兩組則沒有顯著的差異，分別為1.4與0.4，p值為0.419。結論：單鏈抗體一abti-CTLA4scFV，可以延長外來蛋白-大腸桿菌半乳糖酶在正常免疫力小黑鼠的肌肉中表達，其作用機轉可能是作用在已活化的T細胞表面上的受器-CD152，藉活化CD152使得T細胞凋亡，進入anergy，達到降低宿主免疫反應的目的。

關鍵字

免疫調控 ； 轉植基因 ； T細胞受器 ； 單鏈抗體

並列摘要

Objectives: To induce immune tolerance in immune-competent animals with a plasmid (p4F10-eB7) expressing a membranebound single-chain antibody against CTLA4. Materials and Methods: Twenty 9-week old immune-competent C57B/L6 mice were divided into 2 groups. Ten mice received an intramuscular injection of 50 L of endotoxin-free pCBLacZ plasmid at a concentration of 1 mg/mL in phosphate buffer in the left anterior tibialis. The plasmid codes for the potent immunogen, Escherichia coli beta-galactosidase in transduced muscle fibers. Ten mice received a co-injection of p4F10-eB7 with pCBLacZ. Results: We examined the expression of beta-galactosidase in muscle fibers on the 6th and 12th days after the intramuscular injection. The average number of fibers expressing beta-galactosidase was 43.6 in the mice receiving 2 plasmids as compared with 2.2 in the mice receiving only pCBLacZ (p= 0.015, by the Mann-Whitney test). There was no significant difference in the expression of beta-galactosidase between these 2 groups on day 12, at 0.4 Vs 1.4 fibers (p=0.419). Conclusions: Expression of anti-CTLA4 antibody in muscle cells prolonged the expression of a strong immunogen, E. coli beta-galactosidase in transduced muscle fibers of immune-competent mice. The probable mechanism could be anergy of activated cytotoxic T cells induced by activation of CD152 after interaction with the single-chain antibody.

並列關鍵字

immunomodulation ； transgene ； T cell receptor ； single-chain antibody