1. IGM Biosciences, Mountain View, CA 94043, USA
2. Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT 05405, USA
3. Department of Microbiology and Molecular Genetics, Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT 05405, USA
4. Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA