Cohen J L, Boyer O, Salomon B, Onclerco R, Depetris D, Lejeune L, Dubus-Bonnet V, Bruel S, Charlotte F, Mattéï M G, Klatzmann D
CNRS ESA, Laboratoire de Biologie et Thérapeutique des Pathologies Immunitaires, Paris, France.
Transgenic Res. 1998 Sep;7(5):321-30. doi: 10.1023/a:1008893206208.
Dividing cells expressing the Herpes simplex type 1 thymidine kinase (TK) can be killed upon ganciclovir treatment. Likewise, conditional cell knock-out can be obtained in transgenic mice expressing a TK gene placed under the control of tissue-specific regulatory sequences. Such animals provide powerful experimental systems for assessing the functional role of specific cell populations through their time-controlled ablation. However, whatever the regulatory sequences used, a leaky toxic overexpression of TK in testis renders male TK-transgenic mice sterile and prevents the generation of homozygous TK-expressing animals. To solve this problem, we designed a truncated TK variant (delta TK) not expressed in the testis. We generated transgenic mice expressing delta TK under the control of lymphocyte-specific regulatory sequences derived from the CD4 gene. The delta TK protein expressed in T-lymphocytes allowed the conditional ablation of activated T-cells in vitro and in vivo. Importantly, for one transgenic line we could generate fertile homozygous mice harboring a functional delta TK transgene. delta TK should thus dramatically facilitate the development of transgenic mice expressing a conditional suicide gene.
表达单纯疱疹病毒1型胸苷激酶（TK）的分裂细胞在接受更昔洛韦治疗后会被杀死。同样，在表达受组织特异性调控序列控制的TK基因的转基因小鼠中可以实现条件性细胞敲除。这类动物为通过对特定细胞群体进行时间控制的消融来评估其功能作用提供了强大的实验系统。然而，无论使用何种调控序列，睾丸中TK的渗漏性毒性过表达都会使雄性TK转基因小鼠不育，并阻止纯合表达TK的动物的产生。为了解决这个问题，我们设计了一种在睾丸中不表达的截短型TK变体（δTK）。我们构建了在源自CD4基因的淋巴细胞特异性调控序列控制下表达δTK的转基因小鼠。在T淋巴细胞中表达的δTK蛋白能够在体外和体内对活化的T细胞进行条件性消融。重要的是，对于一个转基因品系，我们能够培育出携带功能性δTK转基因的可育纯合小鼠。因此，δTK应该会极大地促进表达条件性自杀基因的转基因小鼠的研发。
