Michail S. Lionakis, M.D., Sc.D.
Fungal Pathogenesis Unit
4 Memorial Drive, Room 228B
Bethesda, MD 20814
Since the 1990s, fungal infections have emerged as a major cause of morbidity and mortality in immunosuppressed and critically ill patients. The yeast Candida is the most common human fungal pathogen and is responsible for both invasive and mucosal infections. Neutrophils and monocytes/macrophages are critical for host defense against invasive candidiasis, the most common deep-seated human mycosis and the fourth-leading cause of nosocomial bloodstream infection in the United States. Despite administration of antifungal therapy, mortality of patients who develop invasive Candida infection exceeds 40 percent. In stark contrast to the requirement of phagocytes for defense against invasive infection, mucosal candidiasis develops 1) in patients with impaired cellular immunity such as those with AIDS (more than 90 percent of whom develop oral thrush) or inborn errors of immunity leading to chronic mucocutaneous candidiasis (CMC) and 2) in the majority of healthy women, often associated with antibiotic use (vaginal candidiasis). In all of these conditions, detailed knowledge of immunopathogenesis at the molecular and cellular levels is lacking.
Our laboratory research focuses on 1) cellular and molecular factors that regulate the immune response against mucosal and invasive candidiasis in clinically relevant animal models and on 2) better understanding the genetic and immune defects that underlie enhanced susceptibility to mucocutaneous and invasive fungal infections in humans. Our goal is to develop a detailed mechanistic understanding of the molecular and cellular basis of innate and adaptive immune responses against Candida with an aim to devise novel strategies to improve the diagnosis and augment or supplement the current antifungal drug treatment against candidiasis. To this end, we utilize in vitro cell culture systems and clinically relevant mouse models of mucosal and systemicCandida infections to study host-fungal interactions by using a variety of immunological, biological, and imaging approaches.
The first step in mounting any immune response is the effective recruitment and activation of immune cells at the site of infection. Yet, the molecular factors that mediate these processes in the setting of candidiasis are poorly defined. Hence, a major focus of the laboratory is to investigate the role of specific members of the chemoattractant system in mediating trafficking and effector function of specific resident and recruited immune cells in anti-Candida host defense in vivo. Characterization of the role of candidate chemotactic factors in antifungal host defense in mice is then followed by human immunogenomics studies, in which genetic polymorphisms in the identified chemotactic factor genes are tested for correlating effects on biological function and for associations with candidiasis in patients.
Further, an important event that determines the outcome of candidiasis is germination of Candida yeast into hyphae. Hence, Candida mutant strains that are unable to germinate are avirulent in vivo. We have previously demonstrated that in disseminated candidiasis, the innate antifungal immune response is highly idiosyncratic for each infected organ, associated with organ-specific differential ability of Candida to filament in these tissues. Thus, our laboratory is interested in delineating the host factors that govern antifungal resistance versus susceptibility at different anatomical sites. To that end, a major focus of our laboratory is the study of the immunological mechanisms that account for central nervous system (CNS)-targeted susceptibility to systemic candidiasis and other systemic fungal infections in patients with CARD9 mutations. Hence, via an investigational review board (IRB)-approved clinical protocol, our lab is recruiting patients with biallelic CARD9 mutations to NIH to study them immunologically. In parallel, the cellular and molecular basis of enhanced susceptibility to CNS-targeted system fungal diseases in CARD9 deficiency is investigated in Card9-/- mice.
With regard to mucosal candidiasis, the laboratory investigates the mechanisms of Candida susceptibility in inherited immunodeficiencies that lead to CMC and in healthy subjects following antibiotic use. Hence, the laboratory aims to define the immunological mechanisms that account for universal susceptibility to CMC in patients with the autosomal-recessive autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome. APECED, caused by mutations in autoimmune regulator (AIRE), is the only primary immunodeficiency in which CMC develops in 100 percent of patients and is the only infectious disease phenotype. Hence, our laboratory, via an investigational review board (IRB)-approved clinical protocol, is recruiting APECED patients to the National Institutes of Health to study them immunologically. In parallel, the cellular and molecular basis of enhanced susceptibility to mucosal candidiasis in APECED is investigated in Aire-/- mice.
In addition, antibiotic use is the most common controllable risk factor for development of vaginal candidiasis in health women. Hence, our laboratory aims to define the microbiomic and immunological perturbations that lead to vaginal candidiasis in antibiotic-treated healthy women. Better understanding of the antibiotic-induced alterations in the commensal flora and mucosal anti-Candidaimmune response that result in vaginal candidiasis could form the basis for development of targeted probiotic and/or immune-based strategies for the prevention and therapy of vaginal candidiasis in humans.
Last, our lab is working with the NIAID Clinical Genomics Program with a goal to identify novel genetic variants that result in inherited susceptibility to fungal infections by Candida, Aspergillus, and other molds.
Dr. Lionakis obtained his M.D. and Sc.D. from the University of Crete in Greece. In 2002, he came to the United States and worked as a research fellow at the University of Texas MD Anderson Cancer Center (MDACC) under the mentorship of Dimitrios Kontoyiannis. At MDACC, Dr. Lionakis did clinical research on risk factors, diagnosis, and management of opportunistic fungal infections in cancer patients and bench research focusing on pharmacology and microbial factors in mouse and Drosophila models of invasive aspergillosis, fusariosis, and candidiasis.
After completing his clinical training in Internal Medicine at Baylor College of Medicine and Infectious Diseases at NIAID, Dr. Lionakis joined the Laboratory of Molecular Immunology (LMI) in 2008 and began to work on fungal immunology under the mentorship of Philip Murphy. At LMI, Dr. Lionakis did bench research on how chemotactic factors regulate the innate immune response in invasive candidiasis. In 2010, he was recruited as an Assistant Clinical Investigator in the NIAID Transition Program in Clinical Research and established the Clinical Mycology Unit within LMI. In 2012, Dr. Lionakis was recruited as a tenure-track investigator in the NIAID intramural research program and established the Fungal Pathogenesis Unit within the Laboratory of Clinical Infectious Diseases.
American College of Physicians (ACP) Walter J. McDonald Award for Early Career Physicians (2017); Fellow of Infectious Diseases Society of America (FIDSA) (2016); IDWeek Investigator Award (2015); BeHEARD Science Prize Winner, Rare Genomics Institute (2015); 50th ICAAC George McCracken Infectious Disease Fellow Award (2010); 49th ICAAC Infectious Disease Fellows Grant Program Award (2009); Henry McIntosh Award for Outstanding Resident in Medicine (2007); Offered Chief Resident position, Baylor College of Medicine (2006); Certificate of Merit, MD Anderson Cancer Center (2004); 1st place Bristol-Myers Squibb Award in Clinical/Translational Research, Trainee Recognition Day, MD Anderson Cancer Center (2004); 43rd ICAAC Program Committee Award for Outstanding Research in the Pathogenesis of Microbial Diseases (2003); Giorgos Gennimatas Scholarship Award (2002); GlaxoWellcome Scholarship Award (2000); Lilian Voudouri Foundation Scholarship Award (2000); The Hellenic National Scholarships' Foundation Scholarship Award (2000); Dretakis Foundation Scholarship Award (2000)
- American College of Physicians
- American Society of Microbiology
- Infectious Diseases Society of America
- Mycoses Study Group
- International Immunocompromised Host Society
- International Society for Human and Animal Mycology
- American Association of Immunologists
- Clinical Immunlogy Society
- American Association for the Advancement of Science
- JCI Insight
- Journal of Infectious Diseases
- Infection & Immunity
- Frontiers in Cellular & Infection Microbiology
- Journal of Visualized Experiments
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Ferré EMN, Break TJ, Burbelo PD, Allgäuer M, Kleiner DE, Jin D, Xu Z, Folio LR, Mollura DJ, Swamydas M, Gu W, Hunsberger S, Lee CR, Bondici A, Hoffman KW, Lim JK, Dobbs K, Niemela JE, Fleisher TA, Hsu AP, Snow LN, Darnell DN, Ojaimi S, Cooper MA, Bozzola M, Kleiner GI, Martinez JC, Deterding RR, Kuhns DB, Heller T, Winer KK, Rajan A, Holland SM, Notarangelo LD, Fennelly KP, Olivier KN, Lionakis MS. Lymphocyte-driven regional immunopathology in pneumonitis caused by impaired central immune tolerance. Sci Transl Med. 2019;11(495).
Lionakis MS, Dunleavy K, Roschewski M, Widemann BC, Butman JA, Schmitz R, Yang Y, Cole DE, Melani C, Higham CS, Desai JV, Ceribelli M, Chen L, Thomas CJ, Little RF, Gea-Banacloche J, Bhaumik S, Stetler-Stevenson M, Pittaluga S, Jaffe ES, Heiss J, Lucas N, Steinberg SM, Staudt LM, Wilson WH. Inhibition of B Cell Receptor Signaling by Ibrutinib in Primary CNS Lymphoma. Cancer Cell. 2017;31(6):833-843.e5.
Swamydas M, Gao JL, Break TJ, Johnson MD, Jaeger M, Rodriguez CA, Lim JK, Green NM, Collar AL, Fischer BG, Lee CC, Perfect JR, Alexander BD, Kullberg BJ, Netea MG, Murphy PM, Lionakis MS. CXCR1-mediated neutrophil degranulation and fungal killing promote Candida clearance and host survival. Sci Transl Med. 2016;8(322):322ra10.
Lionakis MS, Swamydas M, Fischer BG, Plantinga TS, Johnson MD, Jaeger M, Green NM, Masedunskas A, Weigert R, Mikelis C, Wan W, Lee CC, Lim JK, Rivollier A, Yang JC, Laird GM, Wheeler RT, Alexander BD, Perfect JR, Gao JL, Kullberg BJ, Netea MG, Murphy PM. CX3CR1-dependent renal macrophage survival promotes Candida control and host survival. J Clin Invest. 2013;123(12):5035-51.
Related Scientific Focus Areas
Microbiology and Infectious Diseases
Genetics and Genomics
This page was last updated on August 14th, 2019