| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
We previously reported that the 20LK mutation in the HIV-1 matrix (MA) protein impairs the synthesis of HIV-1 viral DNA post-infection without disrupting virus assembly and release, RNA encapsidation, or Env incorporation into virions. We also extensively studied the effects of single amino acid changes throughout MA on virus particle assembly. Although many mutations showed defects in virus assembly and release, Gag processing, or Env incorporation into virions, the effects of these mutations on an early stage of the virus replication cycle were not examined. In this study, we sought to characterize the effects of three MA mutants (6VR, 49LD, 86CS) on early events in the infection pathway. The MA mutants showed modest (6VR) or marked delay in their growth kinetics relative to WT (NL4-3) in various T-cell lines. Each of these three MA mutations do not largely affect virus production, Env incorporation, and Gag processing, although 6VR modestly impairs Gag processing. Interestingly, we observe that the 6VR-induced defect is not reversed by pseudotyping with either the amphotropic murine leukemia virus envelope (ampho-MuLV Env) or VSV-G, whereas 49LD and 86CS are rescued by VSV-G but not ampho-MuLV Env.Real-time PCR analysis indicates that 6VR does not impair the viral DNA synthesis of early reverse transcription (RT) products, but reduces that of late RT products in an infected T-cell line. In contrast, 49LD and 86CS impair the viral DNA synthesis of both early and late RT products. These results suggest that mutants 6VR, 49LD, and 86CS can be a useful tool to elucidate the role of MA in an early post-entry step.
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