Will Bailis, PhD
Assistant Professor of Pathology and Laboratory Medicine
Assistant Professor of Microbiology
Perelman School of Medicine at the University of Pennsylvania
Contact InformationChildren's Hospital of Philadelphia
Abramson Pediatric Research Center
3615 Civic Center Boulevard, Room 1211B
Philadelphia, PA 19104
Email: bailisw@email.chop.edu
Specialty Division
Cancer and Immunobiology
Itmat Expertise
How metabolism regulates immune cell state by controlling cellular biochemical potential
Research Expertise
The Bailis lab aims to understand how metabolism underlies immunology and disease, by controlling the biochemistry of cells and tissues. We do so using in vitro and in vivo CRISPR engineering of primary human and mouse immune cells. Together with next generation sequencing and metabolomics, this permits us to fully interrogate how metabolic networks control immune cell function. Our long-term goal is to use this to develop novel diet and metabolite based therapies.
Our work is currently focused in three major areas:
1) How does spatial compartmentalization of metabolism regulate immune cell state?
Multicellular eukaryotes compartmentalize metabolic information at multiple levels. Within cells, biochemical reactions are separated by the organelles within which they occur. Within tissues, metabolites can be divided between the cells that compose them. Within an animal, different organ systems generate and consume distinct metabolic products that are shared throughout their host. Taking advantage of organelle tagging technologies that allow us to purify immune cell nuclei, ribosomes, and mitochondria from heterogeneous tissues, we aim to elucidate how this biochemical partitioning influences cell programming, tissue patterning, and disease outcome.
2) How does biochemical state control immune cell signaling potential?
In the context of immune cell activation, cellular metabolism is often understood to be one of many biological processes regulated downstream of classic signal transduction. From this top-down view, metabolism is a passive participant in cell reprogramming, acted upon by signaling pathways. There is now a large body of literature illustrating that metabolism can also act in a bottom-up fashion to regulate both signaling effectors as well as epigenetic modifications on the histones that control gene expression. In this manner, the biochemical potential of a cell has the capacity to tune both the quality and quantity of signaling that occurs as well as how that signal is received at target genes in the nucleus. We are actively investigating how signaling relays information through metabolism and how metabolism in turn influences the activity of signaling proteins.
3) How do inborn errors of metabolism impact the immune system?
Inborn errors of metabolism (IEM) are a group of rare genetic disorders that prevent the body from metabolizing food or removing nutrient waste. These defects result in a failure to produce certain essential nutrients or a toxic buildup of metabolites that can cause developmental delays, organ failure, and wasting. While IEM are traditionally not thought of as immunodeficiencies, many individuals with IEM display hallmarks of immune dysfunction, including recurrent and longer lasting infections. Working at Children’s Hospital of Philadelphia, we have the privilege to collaborate with physicians who work with these patients and their families. The goal of our work is to better understand how IEM alter immune cell function, in hopes of improving the care of patients with IEM and learning more broadly how the immune system can be modulated by metabolism. We do so by: 1) working directly with immune cells from IEM patients; 2) modeling the mutations found in these patients using CRISPR/Cas9 engineering of primary human immune cells; 3) performing in vivo infection and vaccination studies with genetic mouse models of these diseases.
Education
BA (Biochemistry), Vassar College, 2008
PhD (Immunology), University of Pennsylvania, 2014
Specialty Certification
Postgraduate Training
Postdoctoral Fellow, Immunometabolism, Yale School of Medicine, 2014-18
Awards and Honors
Oliver M. Lammert Prize for Excellence in Biochemistry, Vassar College, 2008
Distinguished Honors, Vassar College, 2008
Cancer Research Institute Training Award, Cancer Research Institute, 2009
NIH Developmental Biology T32, University of Pennsylvania, 2010
Ruth L. Kirschstein National Research Service Award F31, 2011
CRI Irvington Postdoctoral Fellowship, 2015
Yale Lung SPORE CDP/DRP Award, 2017
NIH NIAID Career Transition Award (K22), 2018
Paul Allen Frontiers Group Distinguished Investigator Award, 2020
NIH NIGMS Maximizing Investigators’ Research Award (R35), 2020
Memberships and Professional Organizations
Society for Leukocyte Biology, 2019-20
American Association of Immunologists, 2020-present
International Cytokine & Interferon Society, 2023-present
Web Links
Selected Publications
Microglia replacement by peripheral delivery of CSF1R inhibitor-resistant hematopoietic cells.
Lombroso SI, Church EI, Anderson RN, O'Brien CA, Zhu Y, Dar AA, Purnell FS, Levitt EM, Temsamrit B, Yaqoob F, Aisenberg WH, Davis M, Elfayoumi B, Chaluvadi S, Nemec KM, Axsom J, Shapiro DA, Oon CH, Chadarevian JP, Assenmacher CA, De Arcangeli S, Banerjee E, Shukla S, Davtyan H, Bailis W, Hunter CA, Blurton-Jones M, Bennett ML, Haney MS, Bennett FC., Molecular Therapy, 2026, PMID:41232525
Microglia replacement by ER-Hoxb8 conditionally immortalized macrophages provides insight into Aicardi-Goutières syndrome neuropathology.
Nemec KM, Uy G, Chaluvadi VS, Purnell FS, Elfayoumi B, Byerly L, O'Reilly ML, O'Brien CA, Aisenberg WH, Lombroso SI, Guo X, Blank N, Oon CH, Yaqoob F, Temsamrit B, Rawat P, Thaiss CA, Bailis W, Williamson AP, Wang Q, Bennett ML, Bennett FC., Elife, 2026, PMID:41589671
Glucose availability tunes latent CD8+ T cell expansion potential through a mitogen-independent, mTOR-dependent regulatory switch
Le VTN, Trihemasava K, Turner L, Rome K, Wu A, Bailis W, bioRxiv, 2026
Environmental Amino Acid Sensing Regulates the Rate of ASC Translation and NLRP3 Inflammasome Assembly
Haggadone MD, Goldspiel BP, O'Farrell A, Kiledjian NT, Knight M, Smith T, Anderson E, Vázquez Marrero VR, Boyer MA, Xu PJ, Scaglione M, Powers ZM, Queriault C, Wu A, Yang Q, O'Riordan MX, Raj A, Mesaros C, Conn CS, Shin S, Bailis W, bioRxiv, 2026
Biosynthetic plasticity enables CD8+ T cell functional resilience under nutrient stress
Scaglione M, Knight M, Trihemasava K, Rome K, Archambault AS, Tanaka E, Hall E, Le V, Lines C, Goldspiel B, Fazelinia H, Queriault C, Turner L, Parnaik T, Xu J, Spruce LA, Bartman C, Mesaros C, Klein Geltink R, Conn CS, Bailis W., Immunity, 2026
Distinct sensing of BCAAs by mTOR and c-Myc governs T cell proliferation, independent of catabolism
Rome K, Hall E, Wu A, Bailis W, EMBO Reports, 2026
Microglia replacement by peripheral delivery of CSF1R inhibitor-resistant hematopoietic cells
Sonia I. Lombroso, Emily I. Church, Ryan N. Anderson, Carleigh A. O’Brien, Yixuan Zhu, Asif A. Dar, Freddy S. Purnell, Eli M. Levitt, Brian Temsamrit, Fazeela Yaqoob, William H. Aisenberg, Mara Davis, Bilal Elfayoumi, Sai Chaluvadi, Kelsey M. Nemec, Jessie Axsom, Daniel A. Shapiro, Chet Huan Oon, Jean Paul Chadarevian, Charles-Antoine Assenmacher, Stefano De Arcangeli, Esha Banerjee, Sangeeta Shukla, Hayk Davtyan, Will Bailis, Christopher A. Hunter, Mathew Blurton-Jones, Mariko L. Bennett, Michael S. Haney, F. Chris Bennett, Molecular Therapy, 2025
BACH2 promotes seeding and establishment of long-lived HIV-1 reservoir in memory CD4+ T cells.
Gao H, Li Y, Tiwari R, Pinzone M, Qin X, Clark KM, Nicholson SK, Yao T, Rome K, Scaglione M, Bailis W, Presti RM, Sereti I, Saligrama N, Wang L, Shan L., Cell Reports, 2025, PMID:40845840
Dumping polyamines helps regulatory T cells "repair" a cancerous relationship.
Trihemasava K, Bailis W., Immunity, 2025, PMID:40803313
Dumping polyamines helps regulatory T cells "repair" a cancerous relationship
Trihemasava T, Bailis W, Immunity 58(): 1885-1887, 2025, PMID:40803313


