Wolff L, Ruscetti S
Proc Natl Acad Sci U S A. 1986 May;83(10):3376-80. doi: 10.1073/pnas.83.10.3376.
Although it has been previously determined that the long terminal repeat (LTR) sequences of several murine retroviruses specify the major tissue tropism of leukemias they induce, data reported here show that the LTR is not responsible for tissue tropism in the case of all leukemogenic viruses. In an effort to determine whether LTR sequences of the acute erythroleukemia-inducing spleen focus-forming virus (SFFV), like those of the other murine leukemia viruses, are uniquely required to confer tissue specificity to the virus, we prepared recombinant SFFVs in which the LTR region containing promoter and enhancer functions was replaced with analogous LTR regions from Friend and Moloney ecotropic and mink cell focus-inducing viruses. It was found that all of the SFFV constructs, even those with a LTR derived from lymphoma-inducing viruses such as Moloney murine leukemia virus, transformed erythroid cells in vitro and induced exclusively an erythroid disease. These results demonstrate that sequences in SFFV that determine the tissue-specific nature of the disease reside outside the LTR.
尽管先前已确定几种鼠逆转录病毒的长末端重复序列（LTR）决定了它们所诱导白血病的主要组织嗜性，但此处报告的数据表明，并非所有致白血病病毒的组织嗜性都由LTR决定。为了确定诱导急性红白血病的脾集落形成病毒（SFFV）的LTR序列是否像其他鼠白血病病毒的LTR序列一样，是赋予病毒组织特异性所唯一必需的，我们制备了重组SFFV，其中包含启动子和增强子功能的LTR区域被来自Friend病毒、莫洛尼嗜亲性病毒和貂细胞集落形成病毒的类似LTR区域所取代。结果发现，所有SFFV构建体，即使是那些具有源自淋巴瘤诱导病毒（如莫洛尼鼠白血病病毒）的LTR的构建体，在体外都能转化红系细胞，并且仅诱导红系疾病。这些结果表明，SFFV中决定疾病组织特异性本质的序列位于LTR之外。
