Role of nucleotide sequences in the V3 region in efficient replication of CCR5-utilizing human immunodeficiency virus type 1 in macrophages.
Macrophages express both CXCR4 and CCR5 coreceptors, but restrict X4 HIV-1 replication unless the Env-V3 region, a major determinant of cell tropism, is exchanged with that of R5 HIV-1. As the V3 exchange concomitantly alters the nucleotide sequences, we introduced silent mutations in the V3 or C2 region of macrophage-tropic R5 JRFL without changing the amino acids. Immunoblot analysis confirmed that viral proteins including Env-gp120 were similarly incorporated in wild-type (wt) and mutant virions. The silent mutants infected CCR5-positive MAGIC5 cells but not CCR5-negative MAGI cells, as productively as wt viruses, indicating that the silent mutations did not alter coreceptor utilization. In contrast, two of three silent V3-mutant viruses failed to replicate efficiently in primary macrophages, whereas other V3- or C2-mutants and wt JRFL infected macrophages productively. Furthermore, synthesis of the full-length viral DNA of the aberrant V3-mutant was largely reduced in macrophages. These results suggest that V3 nucleotide sequences may be one of the postentry factors restricting HIV-1 replication in macrophages.
Department of Pathology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Takayuki
T
Harada
Yasuko
Y
Tsunetsugu-Yokota
Yoshio
Y
Koyanagi
Tetsutaro
T
Sata
Takeshi
T
Kurata
Asato
A
Kojima
D001483:Base Sequence; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D015497:HIV-1 / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008264:Macrophages / Q000821:virology*; D009154:Mutation; D012367:RNA, Viral / Q000737:chemistry*; D019713:Receptors, CCR5 / Q000502:physiology*; D014158:Transcription, Genetic; D014779:Virus Replication
D015699:HIV Envelope Protein gp120; D012367:RNA, Viral; D019713:Receptors, CCR5