Two structurally identical mannose-specific jacalin-related lectins display different effects on human T lymphocyte activation and cell death.

Abstract

Plant lectins displaying similar single sugar-binding specificity and identical molecular structure might present various biological effects. To explore this possibility, the effects on human lymphocytes of two mannose-specific and structurally closely related lectins, Morniga M from Morus nigra and artocarpin from Artocarpus integrifolia were investigated. In silico analysis revealed that Morniga M presents a more largely open carbohydrate-binding cavity than artocarpin, probably allowing interactions with a broader spectrum of carbohydrate moieties. In vitro, Morniga M interacted strongly with the lymphocyte surface and was uptaken quickly by cells. Morniga M and artocarpin triggered the proliferation and activation of human T and NK lymphocytes. A minority of B lymphocytes was activated in artocarpin-treated culture, whereas Morniga M favored the emergence of CD4+ CD8+ T lymphocytes. Moreover, cell death occurred in activated PBMC, activated T lymphocytes, and Jurkat T leukemia cells incubated with Morniga M only. The biological effects of both lectins were dependent on carbohydrate recognition. The Morniga M-induced cell death resulted, at least in part, from caspase-dependent apoptosis and FADD-dependent receptor-mediated cell death. Finally, Morniga M, but not artocarpin, triggered AICD of T lymphocytes. In conclusion, both lectins trigger lymphocyte activation, but only Morniga M induces cell death. In spite of similar in vitro mannose-binding specificities and virtually identical structure, only Morniga M probably interacts with carbohydrate moieties bound to molecules able to induce cell death. The present data suggest that subtle alterations in N-glycans can distinguish activation and cell death molecules at the lymphocyte surface.

• Authors: Hervé Benoist, Raphaël Culerrier, Guillaume Poiroux, Bruno Ségui, Alain Jauneau, Els J M Van Damme, Willy J Peumans, Annick Barre, Pierre Rougé
• Journal: Journal of leukocyte biology (J Leukoc Biol) Vol. 86 Issue 1 Pg. 103-14 (Jul 2009) ISSN: 1938-3673 [Electronic] United States
• PMID: 19401384 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adjuvants, Immunologic
• Mannose-Binding Lectins
• Plant Lectins
• artocarpin lectin
• jacalin
• morniga M

Topics

• Adjuvants, Immunologic (chemistry, pharmacology)
• Antibody-Dependent Cell Cytotoxicity
• Artocarpus (chemistry)
• Cell Death (drug effects)
• Cells, Cultured
• Humans
• Lymphocyte Activation (drug effects)
• Mannose-Binding Lectins (chemistry, pharmacology)
• Morus (chemistry)
• Plant Lectins (chemistry, pharmacology)
• Structure-Activity Relationship
• T-Lymphocytes (cytology, drug effects)