Profiling carbohydrate-receptor interaction with recombinant innate immunity receptor-Fc fusion proteins.
The recognition of bacteria, viruses, fungi, and other microbes is controlled by host immune cells, which are equipped with many innate immunity receptors, such as Toll-like receptors, C-type lectin receptors, and immunoglobulin-like receptors. Our studies indicate that the immune modulating properties of many herbal drugs, for instance, the medicinal fungus Reishi (Ganoderma lucidum) and Cordyceps sinensis, could be attributed to their polysaccharide components. These polysaccharides specifically interact with and activate surface receptors involved in innate immunity. However, due to the complexity of polysaccharides and their various sources from medicinal fungi, quantitative analysis of medicinal polysaccharide extracts with regard to their functions represents a major challenge. To profile carbohydrate-immune receptor interactions, the extracellular domains of 17 receptors were cloned as Fc-fusion proteins, such that their interactions with immobilized polysaccharides could be probed in an enzyme-linked immunosorbent assay. The results show that several innate immune receptors, including Dectin-1, DC-SIGN, Langerin, Kupffer cell receptor, macrophage mannose receptor, TLR2, and TLR4, interact with the polysaccharide extracts from G. lucidum (GLPS). This analysis revealed distinct polysaccharide profiles from different sources of medicinal fungi, and the innate immune receptor-based enzyme-linked immunosorbent assay described here can serve as a high-throughput profiling method for the characterization and quality control of medicinal polysaccharides. It also provides a means to dissect the molecular mechanism of medicinal polysaccharide-induced immunomodulation events.
Hsu
Tsui-Ling
TL
The Genomics Research Center, Academia Sinica, Taipei 115, Taiwan.
Cheng
Shih-Chin
SC
Yang
Wen-Bin
WB
Chin
See-Wen
SW
Chen
Bo-Hua
BH
Huang
Ming-Ting
MT
Hsieh
Shie-Liang
SL
Wong
Chi-Huey
CH
D000818:Animals; D002460:Cell Line; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology*; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology
D007141:Immunoglobulin Fc Fragments; D011134:Polysaccharides; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins