Functional and Phenotypic Characterization of Siglec-6 on Human Mast Cells
Piper A. Robida,
Clayton H. Rische,
Netali Ben-Baruch Morgenstern,
Rethavathi Janarthanam,
Yun Cao,
Rebecca A. Krier-Burris,
Wouter Korver,
Alan Xu,
Thuy Luu,
Julia Schanin,
John Leung,
Marc E. Rothenberg,
Joshua B. Wechsler,
Bradford A. Youngblood,
Bruce S. Bochner,
Jeremy A. O’Sullivan
Affiliations
Piper A. Robida
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Clayton H. Rische
McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
Netali Ben-Baruch Morgenstern
Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
Rethavathi Janarthanam
Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL 60611, USA
Yun Cao
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Rebecca A. Krier-Burris
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Wouter Korver
Allakos, Inc., Redwood City, CA 94065, USA
Alan Xu
Allakos, Inc., Redwood City, CA 94065, USA
Thuy Luu
Allakos, Inc., Redwood City, CA 94065, USA
Julia Schanin
Allakos, Inc., Redwood City, CA 94065, USA
John Leung
Allakos, Inc., Redwood City, CA 94065, USA
Marc E. Rothenberg
Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
Joshua B. Wechsler
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Bradford A. Youngblood
Allakos, Inc., Redwood City, CA 94065, USA
Bruce S. Bochner
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Jeremy A. O’Sullivan
Division of Allergy and Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Mast cells are tissue-resident cells that contribute to allergic diseases, among others, due to excessive or inappropriate cellular activation and degranulation. Therapeutic approaches to modulate mast cell activation are urgently needed. Siglec-6 is an immunoreceptor tyrosine-based inhibitory motif (ITIM)-bearing receptor selectively expressed by mast cells, making it a promising target for therapeutic intervention. However, the effects of its engagement on mast cells are poorly defined. Siglec-6 expression and endocytosis on primary human mast cells and mast cell lines were assessed by flow cytometry. SIGLEC6 mRNA expression was examined by single-cell RNAseq in esophageal tissue biopsy samples. The ability of Siglec-6 engagement or co-engagement to prevent primary mast cell activation was determined based on assessments of mediator and cytokine secretion and degranulation markers. Siglec-6 was highly expressed by all mast cells examined, and the SIGLEC6 transcript was restricted to mast cells in esophageal biopsy samples. Siglec-6 endocytosis occurred with delayed kinetics relative to the related receptor Siglec-8. Co-crosslinking of Siglec-6 with FcεRIα enhanced the inhibition of mast cell activation and diminished downstream ERK1/2 and p38 phosphorylation. The selective, stable expression and potent inhibitory capacity of Siglec-6 on human mast cells are favorable for its use as a therapeutic target in mast cell-driven diseases.
