Human Lymphocyte Stimulation by Legume Lectins from the Diocleae Tribe

Abstract

Lectins from eight leguminous seeds from the Diocleae tribe were compared to Concanavalin A (Con A), a well known T cell mitogen, on the stimulation of lymphocyte proliferation and Interferon gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) from normal volunteers. Lectins from Canavalia brasiliensis and Dioclea virgata induced the highest lymphocyte proliferation, both much higher than levels obtained with Con A, whereas lectins from Dioclea guianensis var. lasiophylla and from Canavalia bonariensis induced the lowest stimulation. Lectins from Dioclea rostrata, D. grandiflora, D. violacea and Cratylia floribunda induced intermediate levels of proliferation. The highest stimulation for IFN-gamma production was obtained with the lectin from D. rostrata, followed by those of C. floribunda and C. brasiliensis; only the lectins from D. virgata and C. bonariensis induced an IFN-gamma production lower than the one obtained by Con A-stimulation. Since all these legumes belong to the same tribe of C. ensiformis (Con A), and all are supposed to exhibit very similar lectins, it is interesting the high variation in the stimulation of lymphocyte proliferation. It is also noteworthy the dissociation between this parameter and IFN-gamma production in the case of D. virgata. A detailed analysis on the structure of such lectins, and their ligand sugars on lymphocyte surface is necessary to further explore such differences.

Inflammatory and anti-inflammatory effects of soybean agglutinin

“…After iv injection of the lectin, the erythrocyte count did not change and significant neutrophilia was observed (data not shown). In addition, the ability of some plant lectins to induce in vitro and in vivo the release/production of cytokines has been described (20). Several cytokines, in addition to their pro-inflammatory effects, also exhibit anti-inflammatory activities (21)(22)(23).…”

Thermodynamic Binding Studies of Lectins from the Diocleinae Subtribe to Deoxy Analogs of the Core Trimannoside of Asparagine-linked Oligosaccharides

“…However, despite the phylogenetic proximity and apparently highly conserved sequences of the above Dioclineae lectins, they possess different biological activities such as histamine release from rat peritoneal mast cells (19), lymphocyte proliferation and interferon ␥ production (20), peritoneal macrophage stimulation and inflammatory reaction (21) as well as induction of paw edema and peritoneal cell immigration in rats (22). Indeed, the importance of determining the fine binding Fig.…”

In vivo lymphocyte activation and apoptosis by lectins of the Diocleinae subtribe

“…These lectins have previously been shown to induce proliferation and interferon-gamma production by peripheral blood mononuclear cells in culture (Barral-Netto et al 1992). Moreover, they presented a higher stimulatory capacity than concanavalin A (ConA), in spite of having over 80% homology with this lectin (Moreira et al 1983, Barcellos et al 1993.…”