4 research outputs found
A single nine-amino acid peptide induces virus-specific, CD8+ human cytotoxic T lymphocyte clones of heterogeneous serotype specificities
It is generally accepted that virus-specific CD8+ cytotoxic T lymphocytes (CTLs) recognize nine-amino acid peptides in conjunction with HLA class I molecules. We recently reported that dengue virus-specific CD8+ CTLs of two different serotype specificities, which were established by stimulation with dengue virus, recognize a single nine-amino acid peptide of the nonstructural protein NS3 of dengue virus type 4 (D4V) in an HLA-B35-restricted fashion. To further analyze the relationships between the serotype specificities of T cells and the amino acid sequence of the recognized peptides, we examined the ability of this viral peptide D4.NS3.500-508 (TPEGIIPTL) to stimulate T lymphocytes of an HLA-B35-positive, dengue virus type 4-immune donor. Peptide stimulation of the PBMC generated dengue virus-specific, HLA-B-35-restricted CD8+ CTL clones. These clones lysed dengue virus-infected autologous cells, as well as autologous target cells pulsed with this peptide. Four patterns of dengue virus serotype specificities were demonstrated on target cells infected with dengue-vaccinia recombinant viruses or pulsed with synthetic peptides corresponding to amino acid sequences of four dengue virus serotypes. Two serotype-specific clones recognized only D4V. Three dengue virus subcomplex-specific clones recognized D1V, D3V, and D4V, and one subcomplex-specific clone recognized D2V and D4V. Three dengue virus serotype-cross-reactive clones recognized D1V-D4V. Thus, a single nine-amino acid peptide induces proliferation of a heterogeneous panel of dengue virus-specific CD8+ CTL clones that are all restricted by HLA-B35 but have a variety of serotype specificities. Peptides that contain a single amino acid substitution at each position of D4.NS3.500-508 were recognized differently by the T cell clones. These results indicate that a single epitope can be recognized by multiple CD8+ CTLs that have a variety of serotype specificities, but the manner of recognition by these multiple CTLs is heterogeneous
Neutralino Dark Matter from MSSM Flat Directions in light of WMAP Result
The minimal supersymmetric standard model (MSSM) has a truly supersymmetric
way to explain both the baryon asymmetry and cold dark matter in the present
Universe, that is, ``Affleck-Dine baryo/DM-genesis.'' The associated late-time
decay of Q-balls directly connects the origins of the baryon asymmetry and dark
matter, and also predicts a specific nature of the LSP. In this paper, we
investigate the prospects for indirect detection of these dark matter
candidates observing high energy neutrino flux from the Sun, and hard positron
flux from the halo. We also update the previous analysis of the direct
detection in hep-ph/0205044 by implementing the recent result from WMAP
satellite.Comment: 32 pages, including 40 figure