Brain-infiltrating cytolytic T lymphocytes specific for Theiler's virus recognize H2Db molecules complexed with a viral VP2 peptide lacking a consensus anchor residue.
Mice expressing the H2b haplotype are resistant to infection with Theiler's murine encephalomyelitis virus (TMEV), which causes chronic demyelination in susceptible mice. The prominent cytolytic T-lymphocyte (CTL) response to the VP2 antigen encoded by TMEV led us to the identification of a class I-binding peptide derived from the VP2 antigen. Escherichia coli transformants overexpressing a series of 11 overlapping VP2 protein fragments were subjected to lysis and alkali digestion, and the resultant peptide pools were tested for their abilities to sensitize RMA-S targets for lysis by CTLs. The source of effector CD8+ T cells for the assays was either freshly harvested central nervous system-infiltrating lymphocytes (CNS-IL) or CNS-IL-derived VP2-specific CTL clones and lines. A 10-residue peptide at VP2 positions 121 to 130 (VP2(121-130)) (FHAGSLLVFM) was identified that sensitized targets for lysis and formed stable complexes with H2Db class I molecules. The VP2(121-130) peptide sensitized target cells for lysis by freshly harvested CNS-IL CTLs at femtomolar concentrations. Despite its relative high level of biological activity, the VP2(121-130) peptide is distinguished from other Db-binding peptides by its lack of an asparagine residue at position five, which had been previously proposed to be a requirement for Db-peptide complexing.
Borson
N D
ND
Department of Immunology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Paul
C
C
Lin
X
X
Nevala
W K
WK
Strausbauch
M A
MA
Rodriguez
M
M
Wettstein
P J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000166:cytology / Q000276:immunology*; D002213:Capsid / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins; D016384:Consensus Sequence; D006183:H-2 Antigens / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D008285:Major Histocompatibility Complex / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D017945:Theilovirus / Q000276:immunology*; D014162:Transfection
D036022:Capsid Proteins; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C442556:VP2 protein, Theilovirus