title: Dectin-1 agonist selectively induces IgG1 class switching by LPS-activated mouse B cells.
abstract: Heat-killed Saccharomyces cerevisiae (HKSC) is an agonist for Dectin-1, a major fungal cell wall β-glucan receptor. We previously reported that HKSC selectively enhances IgG1 production by LPS-activated mouse B cells. To determine if this IgG1 selectivity is caused by selective IgG1 class switching, we performed RT-PCRs for measuring germline transcripts (GLTs), flow cytometric analyses for detecting Ig-expressing cells, and ELISPOT assays for measuring the number of Ig-secreting cells in HKSC/LPS-stimulated mouse B cell cultures. HKSC selectively enhanced expression of GLTγ1, the number of IgG1-expressing cells, and the number of IgG1-secreting B cells in the presence of LPS stimulation. In addition, HKSC induced the expression of CD69, an activation marker for B lymphocytes, and the expression of surface Dectin-1. Two Dectin-1 antagonists, laminarin and a neutralizing Dectin-1 antibody, selectively diminished HKSC-reinforced IgG1 production by LPS-stimulated B cells. Furthermore, depleted zymosan (dzn), a Dectin-1 agonist with increased selectivity, also selectively enhanced GLTγ1 transcription. The Dectin-1 antagonists blocked dzn-induced IgG1 production by LPS-activated B cells. Collectively, these results suggest that Dectin-1 agonists selectively induce IgG1 class switching by direct stimulation of Dectin-1 on LPS-activated B cells resulting in selective production of IgG1.
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
authors: Beom-Seok
authors: BS
authors: Seo
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
authors: Ha-Yan
authors: HY
authors: Park
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
authors: Hee-Kyung
authors: HK
authors: Yoon
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
authors: Yung-Choon
authors: YC
authors: Yoo
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea.
authors: Junglim
authors: J
authors: Lee
authors: Department of Microbiology, Myunggok Medical Research Center, College of Medicine, Konyang University, Daejeon 35365, Republic of Korea. Electronic address: srpark@konyang.ac.kr.
authors: Seok-Rae
authors: SR
authors: Park
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000276:immunology / Q000378:metabolism; D017578:Immunoglobulin Class Switching / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology*; D037181:Lectins, C-Type / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology*; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology*; D051379:Mice; D051193:Toll-Like Receptors / Q000819:agonists / Q000378:metabolism; D015533:Transcriptional Activation / Q000276:immunology; D000099181:Dectin-1
chemical_list: D007074:Immunoglobulin G; D037181:Lectins, C-Type; D008070:Lipopolysaccharides; D051193:Toll-Like Receptors; D000099181:Dectin-1
keywords: B cells; Dectin-1; Germline γ1 transcripts; IgG1; LPS