Mannose receptor structure, ligand recognition, and receptor-mediated endocytosis mechanisms in macrophages and dendritic cells

Abstract

The mannose receptor mediates pathogen recognition and antigen internalization in macrophages and dendritic cells. This research characterized mannose receptor binding properties and endocytic trafficking using recombinant receptor domains and primary human cells. Experiments performed at Jakarta Institute of Applied Sciences from July 2023 to November 2024 employed surface plasmon resonance for binding kinetics and fluorescent ligand tracking for endocytosis measurements. Results showed that the carbohydrate recognition domains bound mannose with Kd values of 2.3 mM for individual domains, while multivalent mannan binding achieved apparent affinity of 4.7 nM through avidity effects. Receptor internalization occurred within 3.2 minutes of ligand binding, with 78% of cargo reaching lysosomal compartments by 30 minutes. Calcium chelation abolished binding, confirming the calcium-dependent lectin mechanism. These findings clarify mannose receptor function in innate immunity and antigen presentation.