The Macrophage Galactose-Type Lectin-1 (MGL1)‎ Recognizes Taenia crassiceps Antigens, Triggers Intracellular Signaling, and Is Critical for Resistance to This Infection

Abstract EN

C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation.

Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages.

Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections.

Macrophages from MGL1−/− mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts.

Exposure of WT macrophages to T.

crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1−/− macrophages.

Following T.

crassiceps infection, MGL1−/− mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice.

In contrast, MGL1−/− mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant.

Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1−/− macrophages.

These studies indicate that MGL1 is involved in T.

crassiceps recognition and subsequent innate immune activation and resistance.