Tewari D, Goldstein S L, Notkins A L, Zhou P
Oral Infection and Immunity Branch, National Institute of Dental Research, Bethesda, MD 20892, USA.
J Immunol. 1998 Sep 1;161(5):2642-7.
HIV-1 gag p17 protein is an attractive target for molecular intervention, because it is involved in the viral replication cycle at both the pre- and postintegration levels. In the present experiments, we targeted p17 by intracellularly expressing a cDNA encoding an Ab to p17. cDNA from a hybridoma-secreting Ab to p17 was cloned, sequenced, reconstructed as a single-chain Ab fragment (scFv), and expressed in the cytoplasm or nucleus with appropriate retention signals. The expressed scFvs had no effect on T cell growth or CD4 expression and bound specifically to HIV-1 p17. Human CD4+ Jurkat T cells that expressed scFvs and were infected with HIV-1 showed a marked reduction in virus replication compared with cells expressing vector alone. The inhibition of virus replication was more pronounced when scFvs were expressed in the cytoplasm rather than the nucleus. From these studies, we conclude that the intracellular expression of a single-chain Ab to p17 inhibits HIV replication; in addition, the degree of inhibition is related to the intracellular targeting site.
HIV-1 gag p17蛋白是分子干预的一个有吸引力的靶点，因为它在整合前和整合后水平都参与病毒复制周期。在本实验中，我们通过在细胞内表达编码针对p17的抗体的cDNA来靶向p17。从分泌针对p17的抗体的杂交瘤中克隆cDNA，进行测序，重建成单链抗体片段（scFv），并在细胞质或细胞核中带有适当的滞留信号进行表达。表达的scFv对T细胞生长或CD4表达没有影响，并能特异性结合HIV-1 p17。表达scFv并感染HIV-1的人CD4+ Jurkat T细胞与仅表达载体的细胞相比，病毒复制明显减少。当scFv在细胞质中而非细胞核中表达时，对病毒复制的抑制更为明显。从这些研究中，我们得出结论，针对p17的单链抗体在细胞内表达可抑制HIV复制；此外，抑制程度与细胞内靶向位点有关。
