02486nas a2200265   4500000000100000008004100001260001200042100001100054700001800065700001500083700001500098700001300113700001300126700001200139700002000151700002000171700001400191700001400205245016900219856007100388300000800459490000700467520173200474022001402206       2020                            d  c01/20201 aLima M1 aCapparelli FE1 aOliveira J1 aFujimura P1 aMoraes E1 aAraujo E1 aSilva N1 aAlves-Balvedi R1 aBrito-Madurro A1 aGoulart I1 aGoulart L00aBiotechnological and Immunological Platforms Based on PGL-I Carbohydrate-Like Peptide of Mycobacterium leprae for Antibodies Detection Among Leprosy Clinical Forms.  uhttps://www.frontiersin.org/articles/10.3389/fmicb.2020.00429/full  a4290 v113 a<p>Phenolic glycolipid I (PGL-I) is an abundant antigen on the  cell wall, commonly used for operational classification of leprosy patients. Our aim was to develop PGL-I mimotopes with similar characteristics and functions of the native antigen. We have used a random peptide  () library for selections against the monoclonal antibody anti-PGL-I. After three selection cycles, six peptides were identified. All sequences were interspersed by a spacer generating a chimeric peptide (PGLI-M3) that was artificially synthesized. The highly reactive peptide was submitted to a reverse  selection with a single-chain Fv (scFv) antibody fragment combinatorial library. The most reactive scFv was then validated by enzyme-linked immunosorbent assay (ELISA) against both native PGL-I and two derived synthetic (NDO and ND-O-HSA). We have further proved the scFv specificity by detecting  bacilli in leprosy lesions through immunohistochemistry. We then described its applicability in ELISA for all clinical forms and household contacts (HC). Afterward, we showed differential binding affinities of PGLI-M3 to sera (anti-PGL-I IgM) from all leprosy clinical forms through surface plasmon resonance (SPR). ELISA IgM detection showed 89.1% sensitivity and 100% specificity, considering all clinical forms. Positivity for anti-PGL-I IgM was twofold higher in both HC and patients with paucibacillary forms in hyperendemic regions than in endemic ones. The SPR immunosensor was able to differentiate clinical forms with 100% accuracy. This is the first time that a PGL-I mimotope has efficiently mimicked the carbohydrate group of the  antigen with successful immunoassay applications and may become a substitute for the native antigen.</p>  a1664-302X