Roman Dziarski (Polish pronunciation: IPA: /ˈrɔ.man//ˈd͡ʑar.ski/ born December 11, 1949) is a Polish-born American immunologist and microbiologist. He is best known for his research on innate immunity and bacterial peptidoglycan, for discovering the family of human peptidoglycan recognition proteins, which comprises PGLYRP1, PGLYRP2, PGLYRP3, and PGLYRP4, and for defining the functions of these proteins.
Dziarski is currently Professor Emeritus of Microbiology and Immunology at Indiana University School of Medicine.
Education
From 1963 to 1967, Dziarski received his secondary education at Reytan High School (Polish: VI Liceum Ogólnokształcące im. Tadeusza Reytana) in Warsaw, Poland, under the tutelage of the revered pedagogue, . From 1967 to 1972, Dziarski attended the University of Warsaw with a major in Biology and Microbiology, which he studied under . He received his Bachelor of Sciences (BS) degree in 1971, and Master of Science (MS) degree in 1972. His MS Thesis was titled, Phenotypic expression of spontaneous mutations to nalidixic acid resistance in Escherichia coli K-12, with Roman Mycielski as his thesis advisor. From 1972 to 1973, Dziarski studied English at West London College in London, England. From 1973 to 1977, Dziarski was a Research Scientist in the Department of Bacteriology at the National Institute of Public Health (Polish: Narodowy Instytut Zdrowia Publicznego – Państwowy Zakład Higieny), Warsaw, Poland, where he performed research for his Doctor of Philosophy (Ph.D.) degree, which culminated in 1977 with the defense of his Ph.D. thesis, titled, Immunobiological properties of Staphylococcus aureus cell wall polysaccharides, with Janusz Jeljaszewicz as his thesis advisor. In September 1977, Dziarski emigrated to the USA.
Academic positions
In 1977, Dziarski joined the Department of Microbiology, Immunology and Pathology at Temple University School of Podiatric Medicine in Philadelphia, Pennsylvania, USA, as a research associate and assistant professor. In 1978, he was promoted to assistant professor and in 1981 to associate professor. In 1985, Dziarski moved to the Department of Microbiology and Immunology at Indiana University School of Medicine–Northwest, in Gary, Indiana, USA, as an associate professor and a full member of the Indiana University Graduate School, in Bloomington, Indiana, USA. In 1991, Dziarski was promoted to a Full Professor of Microbiology and Immunology with tenure. He held this position until his retirement in 2021, when he became Professor Emeritus of Microbiology and Immunology.
Scientific contributions
Role of peptidoglycan in innate immunity
In his early research, Dziarski focused on the role of bacterial peptidoglycan in innate immunity. He showed that peptidoglycan is an immunomodulator and a polyclonal activator of B lymphocytes. He determined the role of DNA synthesis, intracellular calcium, protein kinase C, and inhibitory G proteins in peptidoglycan-induced polyclonal B lymphocyte activation. He also established the role of peptidoglycan and other polyclonal B cell activators in the induction of autoantibody responses in various models of autoimmunity.
Peptidoglycan receptors and cell activation pathways
In his subsequent research, Dziarski set out to identify peptidoglycan receptors on immune cells that mediate the cell-activating and immunomodulating effects of peptidoglycan. His early attempts using biochemical methods were not successful, as they were prone to nonspecific interactions and technical artifacts. He also showed that similar problems and artifacts plagued the early attempts to identify the cell receptors for bacterial lipopolysaccharide and other cell activators.
The molecular biology approach to identifying the cell-activating peptidoglycan receptors was more successful. Using this approach, Dziarski and his research group, in collaboration with Dipika Gupta and her group (also at Indiana University School of Medicine), identified CD14 as the cell-activating receptor for peptidoglycan and showed that CD14 physically binds peptidoglycan. Furthermore, Dziarski's and Gupta's groups identified the involvement of several signal transduction molecules and pathways in peptidoglycan-induced cell activation. Dziarski also established that chemokines are the main pro-inflammatory mediators in human monocytes activated by peptidoglycan and other bacterial cell activators.