Inhibition of cell-free human T-cell leukemia virus type 1 infection at a postbinding step by the synthetic peptide derived from an ectodomain of the gp21 transmembrane glycoprotein.
To investigate the roles of human T-cell leukemia virus type 1 (HTLV-1) envelope (Env) proteins gp46 and gp21 in the early steps of infection, the effects of the 23 synthetic peptides covering the entire Env proteins on transmission of cell-free HTLV-1 were examined by PCR and by the plaque assay using a pseudotype of vesicular stomatis virus (VSV) bearing the Env of HTLV-1 [VSV(HTLV-1)]. The synthetic peptide corresponding to amino acids 400 to 429 of the gp21 Env protein (gp21 peptide 400-429, Cys-Arg-Phe-Pro-Asn-Ile-Thr-Asn-Ser-His-Val-Pro-Ile-Leu-Gln-Glu-Arg-P ro-Pro-Leu-Glu-Asn-Arg-Val-Leu-Thr-Gly-Trp-Gly-Leu) strongly inhibited infection of cell-free HTLV-1. By using the mutant peptide, Asn407, Ser408, and Leu413, -419, -424, and -429 were confirmed to be important amino acids for neutralizing activity of the gp21 peptide 400-429. Addition of this peptide before or during adsorption of HTLV-1 at 4 degrees C did not affect its entry. However, HTLV-1 infection was inhibited about 60% when the gp21 peptide 400-429 was added even 30 min after adsorption of HTLV-1 to cells, indicating that the amino acid sequence 400 to 429 on the gp21 Env protein plays an important role at the postbinding step of HTLV-1 infection. In contrast, a monoclonal antibody reported to recognize the gp46 191-196 peptide inhibited the infection of HTLV-1 at the binding step.
Jinno
A
A
Department of Virology and Preventive Medicine, Gunma University School of Medicine, Showa-machi, Maebashi, Gunma 371-8511, Japan.
Haraguchi
Y
Y
Shiraki
H
H
Hoshino
H
H
D000595:Amino Acid Sequence; D000818:Animals; D002415:Cats; D002460:Cell Line; D015686:Gene Products, env / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D012367:RNA, Viral / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D014158:Transcription, Genetic; D014759:Viral Envelope Proteins / Q000737:chemistry; D010948:Viral Plaque Assay; D054299:env Gene Products, Human Immunodeficiency Virus
D015686:Gene Products, env; D010455:Peptides; D012367:RNA, Viral; D015682:Retroviridae Proteins, Oncogenic; D014759:Viral Envelope Proteins; D054299:env Gene Products, Human Immunodeficiency Virus; C055265:gp21 protein, Human T-lymphotropic virus 1; C055266:gp46 protein, Human T-cell leukemia virus type I