ArtinM Cytotoxicity in B cells derived from Non-Hodgkin’s Lymphoma is regulated by CD45 phosphatase activity and Src family kinases

Abstract

Receptors on the immune cell surface have a variety of glycans that may account for the immunomodulation induced by lectins, which have a carbohydrate recognition domain (CRD) that binds to monosaccharides or oligosaccharides in a specific manner. ArtinM, a D-mannose-binding lectin obtained from Artocarpus heterophyllus, has affinity for the N-glycans core. Immunomodulation by ArtinM toward the Th1 phenotype occurs via its interaction with TLR2-CD14 N-glycans on antigen-presenting cells, as well as recognition of CD3 gamma chain; N-glycans on murine CD4+ and CD8+ T cells. ArtinM exerts a cytotoxic effect on Jurkat human leukemic T cell line and human myeloid leukemia cell line (NB4). The current study evaluated the effects of ArtinM on murine and human B cells derived from non-Hodgkins lymphoma. We found that murine B cells are recognized by ArtinM via the CRD, and the ArtinM stimulus did not augment the proliferation rate or production of IL-2. However, murine B cells incubation with ArtinM augmented the rate of apoptosis, and this cytotoxic effect of ArtinM was also seen in human B cell lines sourced from non-Hodgkins lymphoma Raji cell line. This cytotoxic effect was inhibited by the phosphatase activity of CD45 on Lck, and the protein kinases of the Src family contribute to cell death triggered by ArtinM.

ST8Sia2 polysialyltransferase protects against infection byTrypanosoma cruzi

“…The cell viability of the cells was determined after the reduction of MTT (Sigma-Aldrich) to produce formazan crystals [75]. The procedure was performed as described by Barboza et al [3]. Mitochondrial activity was expressed as a percentage after comparison with the absorbance of unstimulated SH-SY5Y cells.…”

“…Glycans are important regulators in different biological processes, with prominent roles in cell adhesion [1], cell activation and signaling [2,3], modulation of immune responses [4,5], cell death [6], and initiation of tumor progression and metastases [7]. The addition and removal of glycans (mono, oligo and polysaccharides) to proteins, lipids [8] and small RNAs [9] is performed by an array of glycosyltransferases and glycosidases, that act in a concerted way to remodel the cellular glycome [10,11].…”

“…The addition and removal of glycans (mono, oligo and polysaccharides) to proteins, lipids [8] and small RNAs [9] is performed by an array of glycosyltransferases and glycosidases, that act in a concerted way to remodel the cellular glycome [10,11]. Glycosylation is one of the most structurally and functionally complex co-and/or post-translational modifications that occur in cells [12,13]. Glycans attached to glycoconjugates, commonly expressed on the surface of cells, exhibit enormous variability and structural complexity, contributing to their respective biological activities [14].…”