Bioprospection and Selection of Peptides by Phage Display as Novel Epitope-Based Diagnostic Probes for Serological Detection of HTLV-1 and Use in Future Vaccines.

Human T-lymphotropic virus 1 (HTLV-1) is endemic worldwide and the infection results in severe diseases, including Adult T-cell Leukemia (ATL) and HTLV-1 associated myelopathy (HAM). There are some limitations of employing the present commercial serological assays for both diagnostic and epidemiological purposes in different geographical areas of the Brazil, such as the Amazon Region. Currently, methods for diagnosis are usually expensive to adapt for routine use. The aim of this work was to identify and characterize specific ligands to IgG that mimic HTLV-1 epitopes through the Phage Display technique, which could be used for diagnosis and as future vaccine candidates. Initially, IgG from 10 patients with HTLV-1 and 20 negative controls were covalently coupled to protein G-magnetic beads. After biopanning, genetic sequencing, bioinformatics analysis and Phage-ELISA were performed. The technique allowed the identification of 4 clones with HTLV-1 mimetic peptides, three aligned with gp46, A6 (SPYW), B6 (SQLP) and D7 (PLIL), and one with the protease and Tax, A8 (SPPR). Clones A6 and B6 showed higher values of accessibility, antigenicity and hydrophilicity. The reactivity of the clones evaluated by the Receiver Operating Characteristic (ROC) curve showed that the B6 clone had the highest Area Under Curve (0.83) and sensitivity and specificity values (both were 77.27 %; p < 0.001). The study showed that the Phage Display technique is effective for the identification of HTLV-1-related peptides. Clone B6 indicated to be a good marker for bioprospecting diagnostic test for HTLV-1 infection and could be used as a possible vaccine candidate for future studies.

Antioxidant compounds of Kielmeyera coriacea Mart. with α-amylase, lipase and advanced glycation end-product inhibitory activities.

Chronic hyperglycemia and hyperlipidemia are associated with excessive formation of reactive oxygen species and advanced glycation end-products. The present study aimed to evaluate the potential in vitro antidiabetic properties of Kielmeyera coriacea inner bark. The main phytochemical compounds were identified by UHPLC-ESI/MSn and the ethanol extract and its fractions were used to evaluate their antioxidant and anti-glycation capacities, as well as their inhibitory potential against glycoside and lipid hydrolases activities. The polar fractions, especially the n-butanol fraction, had free radical scavenging and quenching properties (ORAC and FRAP values>1800 and 1000 µmol trolox eq/g, respectively, and DPPH IC50<4 µg/mL), and inhibited ROS production (p < 0.01), lipid peroxidation (p < 0.001), glycation (IC50 ~ 10 µg/mL in the BSA-fructose assay; IC50 ~ 200 µg/mL in the BSA-methylglyoxal and arginine-methylglyoxal assays), α-amylase (IC50<0.1 µg/mL) and lipase (IC50<5 µg/mL), with no cytotoxicity. Biomolecules well-known as potent antioxidants were identified for the first time in the inner bark of K. coriacea, such as protocatechuic acid, epicatechin and procyanidins A, B and C. Together, our results support the antioxidant, anti-glycation and glycoside and lipid hydrolases inhibitory properties of the inner bark of K. coriacea, a species found in the Brazilian savanna, which makes it especially useful to combat oxidative stress and hyperglycemia and hyperlipidemia.

Angiogenenic effects of BpLec, a C-type lectin isolated from Bothrops pauloensis snake venom.

The present work reports the effects of a C-type lectin (BpLec) isolated from Bothrops pauloensis snake venom upon in vitro and in vivo angiogenesis models. Initially, we noted that BpLec was not cytotoxic to endothelial cells (tEnd) in doses up to 40µg/mL, but lower doses (2.5µg/mL, 5µg/mL, 10µg/mL and 20µg/mL) reduced tEnd cells adhesion to some extracellular matrix proteins and inhibited the in vitro vessel formation in Matrigel assay stimulated by bFGF. ß-galactosides (d-lactose, N-acetyl-d-galactosamine and d-galactose) at 400mM reversed the effect of BpLec on tEnd cells adhesion, whereas d-galactose (400mM) partially reversed BpLec property of inhibiting vessel formation by tEnd cells in Matrigel. In vivo assays showed that BpLec increased hemoglobin content and capillary vessels number in polyether-polyurethane sponge discs subcutaneously implanted into dorsal skin mice. Additionally, BpLec also reduced collagen deposition and did not induce a pro-inflammatory response, as demonstrated by the decreased the secretion of some inflammatory cytokines, whereas myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activities were not altered by BpLec. Taken together, our results indicate that BpLec might represent an interesting angiogenesis and inflammatory modulator that could also be used for searching possible therapeutic targets involved in these processes.