Kyung J. Kwon-Chung, Ph.D., M.S., B.S.
Molecular Microbiology Section
4 Memorial Drive, Room 228B
Bethesda, MD 20814
The Molecular Microbiology Section is focused on the pathobiology of Cryptococcus neoformans andAspergillus fumigatus, two of the most common and serious fungal pathogens that primarily affect immunocompromised patients. Both C. neoformans and A. fumigatus are environmental pathogens that cause life-threatening systemic disease upon inhalation. The fatality rate of these diseases is high even if treated with the most effective antimycotic agents currently available.
Cryptococcus neoformans, an environmental yeast species most commonly found in pigeon droppings and soil contaminated with avian guano, is the etiologic agent of cryptococcosis. Cryptococcosis has been recognized as an AIDS-defining disease because the major risk group of the disease is people infected with HIV. Although C. neoformans can cause lesions in almost every organ after being inhaled by the host, the most common clinical manifestation and most common cause of death is meningoencephalitis, an infection of the brain. Cryptococcus gattii, a sibling species of C. neoformans, also causes cryptococcosis but more frequently in otherwise healthy patients without well defined underlying risks. The two species share 85 to 90 percent genomic sequence homology but differ significantly in their ecology, epidemiology, and biochemistry. Our section is currently focusing on their differences in pathobiology as well as the way the host responds to the two pathogens.
Cryptococus neoformans Lifecycle
Pathogenic Aspergillus species are ubiquitous in our environment, and humans regularly inhale numerous Aspergillus spores (conidia) during daily life. Of those species, Aspergillus fumigatus is known to be the major cause of life-threatening invasive pulmonary aspergillosis (IPA) in immunocompromised patients throughout the world. The major risk for IPA is profound neutropenia and chronic granulomatous diseae (CGD). However, more than 50 percent of CGD patients, as well as neutropenic patients, do not experience IPA in their lifetime. The Molecular Microbiology Section is currently focused on the pathobiological differences between multiple sibling species that belong to Aspergillus sSection Fumigati and host genetic factors that predispose patients to IPA.
Dr. Kwon-Chung received her B.S. and M.S. in biology from Ewha Womans University in Seoul, South Korea, prior to receiving a Fulbright Scholarship to pursue her doctoral work in the bacteriology department at the University of Wisconsin, Madison. After receiving her Ph.D., she joined the Medical Mycology Section of the NIAID Laboratory of Microbiology as a visiting fellow. She became a senior investigator in the NIAID Laboratory of Clinical Investigation in 1973 and has been the chief of the Molecular Microbiology Section, Laboratory of Clinical Infectious Diseases, since 1995.
Sionov E, Mayer-Barber KD, Chang YC, Kauffman KD, Eckhaus MA, Salazar AM, Barber DL, Kwon-Chung KJ. Type I IFN Induction via Poly-ICLC Protects Mice against Cryptococcosis. PLoS Pathog. 2015;11(8):e1005040.
Chang YC, Khanal Lamichhane A, Bradley J, Rodgers L, Ngamskulrungroj P, Kwon-Chung KJ. Differences between Cryptococcus neoformans and Cryptococcus gattii in the Molecular Mechanisms Governing Utilization of D-Amino Acids as the Sole Nitrogen Source. PLoS One. 2015;10(7):e0131865.
Kwon-Chung KJ, Bennett JE, Wickes BL, Meyer W, Cuomo CA, Wollenburg KR, Bicanic TA, Castañeda E, Chang YC, Chen J, Cogliati M, Dromer F, Ellis D, Filler SG, Fisher MC, Harrison TS, Holland SM, Kohno S, Kronstad JW, Lazera M, Levitz SM, Lionakis MS, May RC, Ngamskulrongroj P, Pappas PG, Perfect JR, Rickerts V, Sorrell TC, Walsh TJ, Williamson PR, Xu J, Zelazny AM, Casadevall A. The Case for Adopting the "Species Complex" Nomenclature for the Etiologic Agents of Cryptococcosis. mSphere. 2017;2(1).
Kwon-Chung KJ, Fraser JA, Doering TL, Wang Z, Janbon G, Idnurm A, Bahn YS. Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis. Cold Spring Harb Perspect Med. 2014;4(7):a019760.
Davis MJ, Moyer S, Hoke ES, Sionov E, Mayer-Barber KD, Barber DL, Cai H, Jenkins L, Walter PJ, Chang YC, Kwon-Chung KJ. Pulmonary Iron Limitation Induced by Exogenous Type I IFN Protects Mice from Cryptococcus gattii Independently of T Cells. MBio. 2019;10(3).
Related Scientific Focus Areas
Microbiology and Infectious Diseases
Genetics and Genomics
Molecular Biology and Biochemistry
This page was last updated on July 25th, 2019