George Hajishengallis, DDS, PhD

Professional Biography

Dr. Hajishengallis earned a D.D.S. from the University of Athens (1989) and a Ph.D. in Microbiology/Immunology from the University of Alabama at Birmingham (1994). He is currently the Thomas W. Evans Centennial Professor at the University of Pennsylvania, School of Dental Medicine. His field of interest lies at the host-microbe interface, where his work has illuminated novel mechanisms of microbial dysbiosis and inflammation as well as inflammation resolution and tissue regeneration. A current focus of his laboratory involves the immunometabolic regulation of trained myelopoiesis and its effects on systemic health and disease. Dr. Hajishengallis combines basic and translational research leading to innovative approaches to clinical problems, such as exemplified by periodontitis, where his preclinical work has recently led to a successful complement-targeted phase 2a clinical trial in patients with periodontal inflammation. In preclinical models of an aggressive form of periodontal disease associated with leukocyte adhesion deficiency type 1 (LAD-1), he established the IL-23/IL-17 axis as the driver of this condition; this concept has been translated to effective treatment of LAD-1 patients at the NIH. His lab has played a crucial role in the identification of Porphyromonas gingivalis as a ‘keystone pathogen’ and in establishing periodontitis as a polymicrobial dysbiotic disease (‘polymicrobial synergy and dysbiosis’ PSD model) rather than an infection, as traditionally thought. Moreover, his work identified a novel homeostatic factor, DEL-1, with anti-inflammatory, pro-resolving and pro-regenerative properties, in a variety of tissues (e.g., periodontium, joints, and central nervous system). More recently, in a publication in CELL, the Hajishengallis lab and collaborators in Germany have identified maladaptive trained myelopoiesis as the mechanistic basis for the bidirectional association of distinct inflammatory comorbidities, as exemplified by the periodontitis-arthritis axis. Dr. Hajishengallis’ research is mostly supported by NIH/NIDCR from which he has received more than $32 million in research funding. Dr. Hajishengallis has published over 235 papers (with more than 36,000 citations; Google Scholar), including in Cell, Nature Immunology, Science Translational Medicine, J. Clin. Invest., Cell Host Microbe, PNAS, N. Engl. J. Med., Nature Reviews Immunology and Nature Reviews Microbiology. He has delivered numerous invited lectures and served as a session chairperson at various national and international research conferences. He has organized multiple scientific conferences in the U.S. and abroad and serves as an Editorial Board Member in several peer-reviewed journals. He is a member of the scientific advisory boards of the Aegean Conferences and of Forsyth Institute as well as of the NIDCR Board of Scientific Counselors. He has mentored multiple graduate students and postdoctoral fellows, many of whom are currently pursuing independent careers in academia. Dr. Hajishengallis received the IADR Distinguished Scientist Award in Oral Biology in 2012 and the NIH/NIDCR MERIT Award in 2016. He was named Highly Cited Researcher (Clarivate/Web-of-Science) in 2018, 2020 2021, 2022, and 2023.

HONORS / CREDENTIALS

• Highly Cited Researcher: Cross-Field category; Clarivate Analytics (2018, 2020, 2021, 2022, 2023)
• Member of the NIDCR Board of Scientific Counselors (2022-present)
• Scientific Advisory Board Member, Forsyth Institute (2020 – Present)
• NIH MERIT Award (2016 – Present)
• Advisory Board Member, Aegean Conferences (2016 – Present)
• Thomas W. Evans Centennial Professor, University of Pennsylvania, Penn Dental Medicine (2015 – Present)
• Editor, Current Topics in Innate Immunity II – Springer (2012); Oral Microbiology and Immunology 2nd ed. – ASM Press (2014); Oral Microbiology and Immunology 3rd ed. – ASM Press (2019); Oral Mucosal Immunity and Microbiome – Springer-Nature (2019)
• AADR/IADR William J. Gies Award in the Biological Research Category (2014)
• Member of the IADR Distinguished Scientist Awards Committee (2013 – 2017); Chair of the IADR Subcommittee for the Research in Oral Biology Award (2016 – 2017)
• IADR Distinguished Scientist Award in Oral Biology (2012)
• Research highlighted in Nature Reviews, Faculty of 1000-Biology, NIH/NIDCR website, Scientific American, AAAS Science Update, AADR’s Strides in Science, WHYY-FM (NPR, Philadelphia), and the popular press
• Associate Editor, Journal of Immunology (2009 – 2013), Molecular Oral Microbiology (2009-present); Journal of Clinical Periodontology (2017 – Present). Editorial Board Member, Journal of Dental Research (2008-2010 & 2016-present).
• Distinguished University Scholar, University of Louisville (2010 – 2011)
• University Scholar, University of Louisville (2005 – 2010)
• Japanese Society for the Promotion of Science (JSPS) fellow (2008)
• Reviewer for NIH Scientific Review Groups (since 2005); Standing Member, NIH/NIDCR Special -Grants Review Committee (DSR) (2014 – Present)
• Faculty Research Excellence Awards, Louisiana State University School of Dentistry (2004 & 2005)

NEWS / MEDIA

• Hajishengallis Lab Sheds Light on an Aging-related Condition that Drives Inflammation 
• Dr. George Hajishengallis, Michel Koo Named Highly Cited Researchers
• Dr. George Hajishengallis Named a 2022 Highly Cited Researcher
• Inflammatory Disorders: Does the Immune System Remember Past Infections?
• How One Inflammatory Disorder Exacerbates Another
• A Two-Pronged Approach to Keep Rheumatoid Arthritis in Check
• Dr. George Hajishengallis Named Highly Cited Researcher for 2021
• Tracking the Downside of Immunity: An Oral-Systemic Health Connection
• Priming the Immune System to Attack Cancer »
• New Insights into Autoimmune Disease »
• Stimulating Immune Cleanup Crew Offers Affordable Possibility for Treating Rare Genetic Disorder »
• To Resolve Inflammation, Location Matters »
• Drivers of Inflammation Provide Valuable Targets for New Gum Disease Therapies »
• By Altering Bone Marrow, ‘Training’ Can Prepare Innate Immune System for Future Challenges »
• Bone Marrow Protein May Be Target for Improving Stem Cell Transplants »
• Translating Science to Practice: Discovery Beyond Dentistry »
• Penn Dental Research Leads to Treatment for Rare Gum Disease »
• George Hajishengallis Receives NIH MERIT Award »
• Complement Inhibitor Reverses Periodontitis »
• Penn Team Reverses Signs of Naturally Occurring Chronic Periodontitis »
• Penn Dental Blocks Bone Loss: Implications for Osteoporosis, RA »
• AAAS Science Update: Gum Disease »
• Penn Dentists Identify Protein that Prevents Bone Loss »
• Penn Dental Medicine Study Blocks Inflammatory Bone Loss in Gum Disease »
• Dr. George Hajishengallis: Sinking His Teeth in to Exciting Research Questions in Periodontal Disease »
• Scientists Find Single Protein That Blocks MS Relapses, Cures Gum Disease »
• Collaborative Penn-Dresden Study Blocks Multiple Sclerosis Relapses in Mice »
• Scientific American: Gingivitis Bacteria Triggers a Tailspin in Your Mouth »
• Gum Disease Bacteria Selectively Disarm Immune System, Penn Study Finds »
• Penn Team Identifies Promising New Target for Gum Disease Treatment »
• Penn Dental Medicine-NIH Team Reverses Bone Loss in Immune Disorder »
• Penn-Led Research Suggests a New Strategy to Prevent or Halt Periodontal Disease »
• New Target for Periodontal Disease »
• New Penn Dental Researcher George Hajishengallis Gets at the Root of Gum Disease »
• The Pros and Cons of Oral Bacteria »
• Growing a World-Class Faculty »
• Mouse study explains bacterium’s unique role in periodontitis: NIH-supported study solves the mystery of a devious oral bacterium »

Selected Publications

Education

• Ph.D., Cellular & Molecular Biology, University of Alabama at Birmingham, 1994
• D.D.S., University of Athens, Greece, 1989

Laboratory Site

View the Hajishengallis Lab »