rBet v 1a-BanLecwt induce upregulation of IL-10 and IFN-γ gene expression in Caco-2/THP-1 co-culture and secretion of IL-10 and IFN-γ/IL-4 levels in PBMCs of birch pollen allergic donors

Abstract

Novel allergen immunotherapy (AIT) approaches necessitate the use of more effective and safe therapeutics, which can be accomplished by employing novel adjuvants for improved innate immune cell activation, as well as hypoallergenic allergen forms. In this study, we investigate the immunomodulatory effects of a chimera rBet v 1a-BanLec_wt (rBv1a-BL_wt; C_wt) composed of the major birch pollen allergen Bet v 1a and banana lectin (BanLec_wt; BLwt) and two novel chimeras, rBv1l-BL_H84T (rBet v 1l-BanLec_H84T; C1) and rBL_H84T-Bv1l (rBanLec_H84T-Bet v 1l; C2), both composed of BL_H84T and hypoallergenic birch pollen allergen Bv1l in the co-culture model Caco-2/THP-1, and PBMCs from donors with birch pollen allergy. The chimeric molecules rBv1l-BL_H84T (C1) and rBL_H84T-Bv1l (C2) were created in silico and then produced in E. coli using recombinant DNA technology. Real-time PCR analysis of gene expression following compound treatment in the co-culture model revealed that all three chimeras have the potential to induce the anti-inflammatory cytokine IL-10 gene expression in Caco-2 cells and IFN-γ gene expression in THP-1 cells. Sandwich ELISA revealed that Cwt increased IL-10 secretion and IFN-/IL-4 levels in PBMCs from birch pollen allergic donors, whereas C1 and C2 were less effective. The findings suggest that Cwt should be analyzed further due to its potential benefit in AIT.

Keywords: Allergen immunotherapy; Allergy; Banana lectin; Bet v 1; Caco-2; THP-1 cells.