Structure-function study of the p55 subunit of murine IL-2 receptor by epitope mapping.
Using a cell-free translation system we have expressed the Mr 55,000 subunit of the murine IL-2R (p55 IL-2R), which binds IL-2 with low affinity (Kd = 10 nM). Mutants and truncated forms of p55 IL-2R have been used to map the epitopes recognized by three anti-p55 IL-2R mAb: 135D5, 7D4, and 2E4. The mAb 135D5 inhibits IL-2 binding to p55 IL-2R and recognizes an epitope located between amino acids 64 to 125. This epitope can be mimicked by a synthetic peptide corresponding to the region defined by residues 72 to 88. However, the mAb 7D4 and 2E4 do not affect the IL-2 binding to p55 IL-2R. These mAb recognize an epitope of p55 IL-2R lying between residues 125 to 212 that can be mimicked with a peptide corresponding to amino acids 188 to 208. A strong correlation emerged between the experimental results on epitope mapping and predictions of potential antigenicity of murine p55 IL-2R. In addition, we described two internal initiation sites of p55 IL-2R mRNA under the in vitro conditions used leading to the production of significant amounts of N-terminal truncated p55 IL-2R proteins.
Lorenzo
F
F
Unité d'Immunogénétique Cellulaire, Institut Pasteur, Paris, France.
Jaulin
C
C
Vita
N
N
Froussard
P
P
Ferrara
P
P
Jankovic
D L
DL
Theze
J
J
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D015153:Blotting, Western; D004252:DNA Mutational Analysis; D000939:Epitopes; D051379:Mice; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011233:Precipitin Tests; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013329:Structure-Activity Relationship
D000911:Antibodies, Monoclonal; D000939:Epitopes; D009841:Oligonucleotides; D010455:Peptides; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins