Effect of BjcuL, a lectin isolated from Bothrops jararacussu, on human peripheral blood mononuclear cells

Abstract

BjcuL is a C-type lectin with specificity for the binding of β-d-galactose units isolated from Bothrops jararacussu venom. It triggers cellular infiltration in post capillary venules, increases edema and vascular permeability in murine models, contributes to in vitro neutrophil activation and modulates macrophage functional activation towards an M1 state. The purpose of this study was to investigate the effect of BjcuL on human peripheral blood mononuclear cells (PBMCs) activation with a focus on PBMCs proliferation and inflammatory mediators release. Results showed that BjcuL is not toxic to PBMCs, that BjcuL inhibits PBMCs proliferation and that it stimulates PBMCs to produce superoxide anion and hydrogen peroxide, primarily via lymphocyte stimulation, but does not stimulate the production of nitric oxide and PGE. These results demonstrate that BjcuL has an immunomodulatory effect on PBMCs. Further studies are needed to confirm the immunomodulatory effect of BjcuL, to elucidate the molecular mechanisms of action responsible for its effects and to determine its potential application as an immunopharmacological and biotechnological tool.

Lectin isolated from Bothrops jararacussu venom induces IL-10 release by TCD4+ cells and TNF-α release by monocytes and natural killer cells

“…BjcuL triggers inflammation with cellular infiltration in postcapillary venules, induces oedema formation and increases vascular permeability in murine models, contributes to in vitro neutrophil activation, modulates macrophage functional activation toward an M1 state, and inhibits PBMCs proliferation …”

“…BjcuL was purified according to Pires et al . In brief, 100 mg of B. jararacussu venom was solubilized in CaTBS buffer (0.02 M Tris, 0.15 M NaCl, and 0.01 CaCl 2 ) (pH 7.4), and it was clarified by centrifugation at 3500 g for 5 min.…”

“…Blood was donated by healthy volunteers who had not used any medication in the last 48 h. Blood was collected in vacuum tubes containing heparin and diluted in PBS (14 mM NaCl, 2 mM NaH 2 PO 4 ⋅H 2 O, 7 mM Na 2 HPO 4 ⋅12H 2 O) (pH 7.4). PBMCs were isolated by a density gradient method as described by Pires et al . using Histopaque 10771 (Sigma, St. Louis, MO, USA) per the manufacturer's instructions.…”

“…PBMCs (1 × 10 6 ) resuspended in RPMI assay medium were plated and incubated with RPMI (negative control), Con‐A (5 µg/ml), LPS (1 µg/ml), PMA (500 ng/mL) (positive controls), or different concentrations of BjcuL (5 and 10 µg/ml) at 37°C in a humidified atmosphere (5% CO 2 ) for 4, 12, 24, 48, 72, and 96 h; because of Pires et al . verified that BjcuL at 5 and 10 µg/ml did not stimulate lymphocyte proliferation.…”

“…A C‐type lectin called BjcuL was isolated from Bothrops jararacussu snake venom. BjcuL has specificity for β‐ d ‐galactose unit binding, conferring on it a wide variety of biological activities . It has already been documented that BjcuL binds to lactose moieties and induces agglutination of erythrocytes.…”