Variable binding affinities of listeriolysin O peptides for the H-2Kd class I molecule.
Previously we used the peptide-binding motif for the murine class I major histocompatibility complex molecule H-2Kd to identify a nonamer peptide of the Listeria monocytogenes listeriolysin (LLO) protein that was recognized by cytotoxic T lymphocytes (CTL) in association with H-2Kd. Eleven nonamer peptides contained in the LLO sequence were synthesized and one, LLO 91-99, proved to be a CTL target. Using peptide binding competition assays with H-2Kd-restricted CTL, we show that 3 out of the 11 LLO peptides, including the CTL epitope, have a high binding affinity for H-2Kd; 2 of 11 peptides have approximately 10-fold lower affinity, while the remaining 6 peptides have no or very low affinity for H-2Kd. Single residue changes were made in the LLO 91-99 peptide and two other LLO peptides to identify non-anchor amino acids that might interfere with peptide binding. In addition, we used the LLO peptides which bound well to H-2Kd to attempt to restimulate a secondary CTL response from L. monocytogenes-primed spleen cells. Only LLO 91-99 was able to induce such a response. Thus only a fraction of nonamer peptides which fit the original binding motif have a high affinity for the H-2Kd class I molecule, and only a fraction of these serve as CTL epitopes.
Wipke
B T
BT
Department of Immunology, University of Washington, Seattle 98195.
Jameson
S C
SC
Bevan
M J
MJ
Pamer
E G
EG
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins; D001667:Binding, Competitive; D006183:H-2 Antigens / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D006460:Hemolysin Proteins; D008089:Listeria monocytogenes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D010446:Peptide Fragments; C038705:hlyA protein, Listeria monocytogenes