College of Veterinary Science Punjab Agricultural University, Ludhiana, India
Russ. J. Immunol. 1999, July 15, 4 (2), 151-158.
Cross-reactions of anti-human chorionic gonadotropin-b (HCG-beta) antibody elicited by HCG-beta based antifertility vaccines with other autoantigens may occur due to identical or homologous protein subsequences. I have detected hitherto unreported identity of HCG-beta sequence with tetrapeptides of PECAM-1, galactosyl transferase-associated protein kinase, insulin receptor-related receptor and carboxypeptidase E. A predicted potential epitope of C-terminal peptide (CTP) of HCG-beta was identical to a tetrapeptide stretch of MCSF-1. The first 30 residue stretch of CTP was found to have yet unknown homologies of more than 56% with many auto-antigens including 60.1% with centromere protein C. The last 30 residue stretch of CTP was found for the first time to have 61.4%-65.4% homology with subsequences of autoantigens SP-100, PM-SCL, D1 (64 kDa), lupus KU (p86), small nuclear ribonucleoprotein-associated proteins N, B and B’, major centromere autoantigen B, centromere protein C, and dihydrolipoamide acetyl transferase component E2 of pyruvate, respectively.