A polypeptide encoded within the murine AIDS defective virus stimulates primary proliferation of CD8+ T-cells.
The murine AIDS (MAIDS) is a retrovirus-induced disease that shows severe immunodeficiency with abnormal lymphoproliferation in susceptible strains of mice. To clarify the antigenicity of gag gene products of the LP-BM5 defective virus, which is known as the causative virus of MAIDS, we expressed and purified the gag p12 gene product (P12) by using a baculovirus expression vector system. The P12 protein strongly stimulated the proliferation of normal C57BL/6 (B6) lymph node T-cells in vitro. Furthermore, a 25-mer synthetic polypeptide within the P12 sequence gave rise to the similar or even higher activation of T-cells. The phenotype of responding T-cells was found to be CD8+ CD44low, indicating that naive CD8+ T-cells respond against a peptide encoded within a MAIDS defective virus gag p12 gene. Finally, the expression of T-cell receptor (TcR) V beta on the responding CD8+ T-cells was analyzed. Although CD8+ T-cells with the particular V beta chains were expanded in response to the 25-mer peptide, this polypeptide does not seem to be a superantigen, since this response is MHC class I-restricted and the V beta preference is not striking. The presentation pathway of this highly antigenic polypeptide will be discussed.
Yee
S T
ST
Department of Bacterial and Blood Products, National Institute of Health, Tokyo, Japan.
Abe
E
E
Okada
Y
Y
Matsuura
Y
Y
Takebe
Y
Y
Ogasawara
K
K
Takahashi
H
H
Mizuochi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D002455:Cell Division; D002460:Cell Line; D002478:Cells, Cultured; D003673:Defective Viruses / Q000737:chemistry; D015683:Gene Products, gag / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D018960:Hyaluronan Receptors / Q000276:immunology; D009052:Leukemia Virus, Murine / Q000737:chemistry; D008198:Lymph Nodes / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D018411:Spodoptera / Q000166:cytology; D014407:Tumor Cells, Cultured
D015683:Gene Products, gag; D015395:Histocompatibility Antigens Class I; D018960:Hyaluronan Receptors; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta