Identification of mimotopes of platelet autoantigens associated with autoimmune thrombocytopenic purpura.
GPIIb/IIIa, the human platelet glycoprotein complex, is the autoantigen most commonly recognized by autoantibodies in autoimmune thrombocytopenic purpura (AITP). Two murine monoclonal antibodies (mAbs), namely Y2/51 and 5B12, directed against gpIIIa and gpIIb/IIIa, respectively, and rabbit anti-human platelet polyclonal antibodies have been used to select AITP-related epitopes from a phage display peptide library expressing random dodecapeptides in the pIII coat protein of M13 phage. The selected phage clones were tested by ELISA for binding to rabbit anti-human platelet antibodies as well as to sera from AITP patients. Seven clones reacted strongly with rabbit anti-human platelet antibodies, and four clones reacted with sera from AITP patients. Some homology between peptide inserts sequences of selected clones and human platelet gpIIIa and gpIb were found.
Gevorkian
G
G
Instituto de Investigaciones Biomedicas, Universidad Nacional Autonoma de Mexico, Mexico, D.F., Mexico. gokar@servidor.unam.mx
Manoutcharian
K
K
Govezensky
T
T
Cano
J A
JA
Dominguez
V
V
Santamaria
H
H
Larralde
C
C
D000818:Animals; D001324:Autoantigens / Q000032:analysis*; D017104:Bacteriophage M13 / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D006801:Humans; D051379:Mice; D018716:Molecular Mimicry; D009842:Oligopeptides / Q000032:analysis / Q000276:immunology; D019151:Peptide Library; D010449:Peptide Mapping; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology*; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
D001324:Autoantigens; D000939:Epitopes; D009842:Oligopeptides; D019151:Peptide Library; D019039:Platelet Glycoprotein GPIIb-IIIa Complex