Establishment of a MAGI-derived indicator cell line that detects the Nef enhancement of HIV-1 infectivity with high sensitivity.
The Nef protein of the simian and human immunodeficiency viruses (SIV and HIV) is regarded as one of the critical determinants of the pathogenicity of HIV-1 in vivo. The positive effect of Nef on viral replication is examined most easily in vitro by the use of indicator cells such as HeLa-CD4-LTR-beta-gal cells (MAGI) or MAGIC5 cells, which are MAGI-derived, CCR5-expressing cells. However, Nef increases the infectivity of many HIV-1 strains no more than 10-fold in these indicator cells. It was noted that MAGI cells expressing a lower level of CD4 enabled us to discriminate more clearly between wild-type and Nef-defective virions. A MAGIC5-derived cell line, MAGNEF, which stably expressed a low level of CD4, was established. The infectivity of the Nef-defective HIV-1 NL4-3 strain was consistently less than one-twentieth of that of the wild type in MAGNEF cells. By using MAGNEF cells, it was shown that Nef enhanced the infectivity of a subtype C HIV-1, Indie-C1 strain, although the effect of Nef on Indie-C1 was significantly less than that on the subtype B strains NL4-3 and SF2. These results validate the versatility of MAGNEF cells for use in the simple and sensitive assay for the level of Nef dependence of various HIV-1 isolates.
Tobiume
M
M
Department of Pathology, Research Institute, International Medical Center of Japan, 162-8655, Tokyo, Japan.
Takahoko
M
M
Tatsumi
M
M
Matsuda
M
M
D015704:CD4 Antigens / Q000235:genetics / Q000378:metabolism; D002999:Clone Cells / Q000378:metabolism / Q000821:virology; D015967:Gene Expression Regulation, Viral; D015693:Gene Products, nef / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D012680:Sensitivity and Specificity; D012692:Serial Passage; D014779:Virus Replication; D054311:nef Gene Products, Human Immunodeficiency Virus
D015704:CD4 Antigens; D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus