Evidence that insulin-like growth factor 2 (IGF2) is the dominant thymic peptide of the insulin superfamily.
The central T-cell tolerance of neuroendocrine functions has been proposed to be primarily induced by the thymic repertoire of neuroendocrine self antigens. The present study aimed at characterizing the human thymic insulin-related autoantigen able to represent the pancreatic B-cell function in face of the developing T-cells. Immunofluorescence studies were performed on human and rat thymic sections, as well as on the rat IT-45R1 thymic epithelial cell line using several antibodies to epitopes of the insulin peptide superfamily. These studies identify beyond any doubt that insulin-like growth factor 2 (IGF2) is the dominant thymic peptide of the insulin family. The sequence of an insulin-derived autoantigen is proposed. This autoantigen is a nonamer and has a hydrophobic residue leucine (L) at position 9. In the human species, this autoantigen would primarily be tolerogenic for the pancreatic B-cell endocrine function during fetal development.
Geenen
V
V
Institute of Pathology, University of Liège-Sart Tilman, Belgium.
Achour
I
I
Robert
F
F
Vandersmissen
E
E
Sodoyez
J C
JC
Defresne
M P
MP
Boniver
J
J
Lefebvre
P J
PJ
Franchimont
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000032:analysis; D002478:Cells, Cultured; D002675:Child, Preschool; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007335:Insulin-Like Growth Factor II / Q000032:analysis*; D008214:Lymphocytes / Q000276:immunology; D008969:Molecular Sequence Data; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000737:chemistry*
D001324:Autoantigens; D007335:Insulin-Like Growth Factor II