Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 17 2 2018 04 28 144 150 EN Parvin Mosadeghi Department of Biology, Basic Science Faculty, Payam Noor University of Mashhad, Mashhad, Iran Hafez Heydari-Zarnagh Cellular and Molecular Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran 2017 06 20 2017 07 08 We aimed to develope a peptide-based indirect ELISA to detect antibodies against Human T-lymphotropic virus type I (HTLV-I). Two chimeric peptides (CP-1 and CP-2) were designed using linear immunodominant epitopes of gp-46-I, and gp21-I proteins, according to the sequence from Uniprot database. These peptides were studied initially in the ELISA using infected sera. The most promising peptideCP-1, was used to develop a peptide ELISA for detection of HTLV-I infected sera. The optimal conditions for CP-1ELISA were: the optimum coating buffer was 100mM NaHCO3, pH 9.6; coating peptide concentration was 10 µg/mL; the optimal blocking buffer was5% fetal bovine serum (FBS); the secondary antibody concentration was 1:2000; and serum dilution was 1:20. 20serum samples from HTLV-I infected patients were evaluated by ELISA developed. CP-1 showed high antigenicity while lacking any cross-reactivity with normal human sera. The results of evaluations indicated that in comparison with commercial ELISA, CP-1 ELISA showed good sensitivity and specificity. With further validation, CP-1as described in the present study could be introduced as novel reliable and cost-effective candidates for the high-specific screening of HTLV-I/-II infections in endemic regions. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/1524 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/1524/826