Nonmyeloablative conditioning is sufficient to allow engraftment of EGFP-expressing bone marrow and subsequent acceptance of EGFP-transgenic skin grafts in mice
Nonmyeloablative conditioning is sufficient to allow engraftment of EGFP-expressing bone marrow and subsequent acceptance of EGFP-transgenic skin grafts in mice
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DOI：
10.1182/blood-2002-06-1649
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发表时间：
2003-06-01
期刊：
影响因子：
20.3
通讯作者：
Down, JD
中科院分区：
文献类型：
--
作者：
Andersson, G;Illigens, BMW;Down, JD
针对基因治疗产品的免疫反应可能被证明是临床基因治疗方案中的常见问题。增强型绿色荧光蛋白（EGFP）通常用作基因转移方案中的标记物，并且已经记录了针对表达EGFP的细胞的免疫应答。本研究旨在研究药物、非清髓性预处理方案对EGFP（+）供/受者混合骨髓嵌合体的发展以及随后对表达EGFP的移植物的耐受性的影响。为此，C57 BL/6 J（136）小鼠用白消安（Busulfex）或密切相关的化合物曲磺凡的可溶性制剂处理，随后移植来自EGFP转基因（B6-EGFR.Tg）供体小鼠的骨髓细胞。这种预处理方案导致供体EGFP（+）细胞在血液、骨髓和胸腺的各种造血谱系中长期存在。在骨髓移植（BMT）后10至17周，用B6-EGFP.Tg皮肤移植物移植的稳定造血嵌合体都接受了它们的移植物，而非EGFP嵌合体B6对照动物能够对EGFP（+）B6皮肤移植物产生排斥。来自主要组织相容性复合体（MHC）不匹配小鼠的对照第三方移植物在20天内被排斥，表明接受表达EGFP的皮肤移植物是通过移植EGFP转基因骨髓诱导特异性免疫耐受的结果。嵌合受体对EGFP的长期耐受性通过不存在抗EGFP反应性T细胞和抗体来证实。这些结果拓宽了使用造血分子嵌合体在非骨髓清除受体中作为预防转基因细胞排斥的一种手段的治疗潜力。(C)2003年，美国血液学会。
Immunologic reactions against gene therapy products may prove to be a frequent problem in clinical gene therapy protocols. Enhanced green fluorescence protein (EGFP) is commonly used as a marker in gene transfer protocols, and immune responses against EGFP-expressing cells have been documented. The present study was designed to investigate the effect of a pharmacologic, nonmyeloablative, conditioning regimen on the development of EGFP(+) donor/recipient mixed bone marrow chimerism and ensuing tolerance to EGFP-expressing transplants. To this end, C57BL/6J (136) mice were treated with soluble formulations of either busulfan (Busulfex) or the closely related compound treosulfan, followed by transplantation of bone marrow cells from EGFP-transgenic (B6-EGFR.Tg) donor mice. Such conditioning regimens resulted in long-term persistence of donor EGFP(+) cells among various hematopoietic lineages from blood, bone marrow, and thymus. Stable hematopoietic chimeras transplanted at 10 to 17 weeks after bone marrow transplantation (BMT) with B6-EGFP.Tg skin grafts all accepted their transplants, whereas non-EGFP chimeric B6 control animals were able to mount rejection of the EGFP(+) B6 skin grafts. Control third-party grafts from major histocompatibility complex (MHC)-mismatched mice were rejected within 20 days, indicating that acceptance of EGFP-expressing skin grafts was the result of specific immune tolerance induction by the transplantation of EGFP-transgenic bone marrow. Long-term tolerance to EGFP in chimeric recipients was confirmed by the absence of anti-EGFP-reactive T cells and antibodies. These results broaden the therapeutic potential for using hematopoietic molecular chimerism in nonmyeloablated recipients as a means of preventing rejection of genetically modified cells. (C) 2003 by The American Society of Hematology.