ArtinM Mediates Murine T Cell Activation and Induces Cell Death in Jurkat Human Leukemic T Cells

The recognition of cell surface glycans by lectins may be critical for the innate and adaptive immune responses. ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus, activates antigen-presenting cells by recognizing TLR2 N-glycans and induces Th1 immunity. We recently demonstrated that ArtinM stimulated CD4(+) T cells to produce proinflammatory cytokines. Here, we further studied the effects of ArtinM on adaptive immune cells. We showed that ArtinM activates murine CD4(+) and CD8(+) T cells, augmenting their positivity for CD25, CD69, and CD95 and showed higher interleukin (IL)-2 and interferon (IFN)-γ production. The CD4(+) T cells exhibited increased T-bet expression in response to ArtinM, and IL-2 production by CD4(+) and CD8(+) T cells depended on the recognition of CD3εγ-chain glycans by ArtinM. The ArtinM effect on aberrantly-glycosylated neoplastic lymphocytes was studied in Jurkat T cells, in which ArtinM induced IL-2, IFN-γ, and IL-1β production, but decreased cell viability and growth. A higher frequency of AnnexinV- and propidium iodide-stained cells demonstrated the induction of Jurkat T cells apoptosis by ArtinM, and this apoptotic response was reduced by caspases and protein tyrosine kinase inhibitors. The ArtinM effects on murine T cells corroborated with the immunomodulatory property of lectin, whereas the promotion of Jurkat T cells apoptosis may reflect a potential applicability of ArtinM in novel strategies for treating lymphocytic leukemia.