Enteroviral molecular biology.
My laboratory closed for good in mid-2015 when I retired and became Emeritus. I no longer conduct bench research. The primary interest of my laboratory was understanding the biology of a common human enterovirus called coxsackievirus B3. Since 1987 when I joined the UNMC faculty, the laboratory obtained constant funding from diverse sources and published numerous basic research papers, book chapters, monographs and reviews dealing with the molecular biology, immunology, and pathogenesis of the coxsackie B viruses. The laboratory was nationally and internationally known and respected and trained numerous students and post-docs. My research, begun in Berkeley in the early1980s, illuminated the role of the group B coxsackieviruses as human disease pathogens and developed these viruses as a valuable virological research system with which to better understand the molecular biology of enteroviruses in general. The work clarified the role of enteroviruses in the causation of acute myocarditis, a disease of the heart muscle which can be lethal or lead to chronic inflammatory heart disease. We demonstrated how enteroviruses can either cause or protect mice from type 1 diabetes (T1D), work which indicated that an enterovirus-based vaccine should be able to suppress T1D onset and discussed in depth the concept that modern living in a hygienic environment, so different from past human history, led to the increase in T1D cases in modern times. My laboratory demonstrated a variety of approaches to stably attenuate the pathogenicity of coxsackieviruses, and by inference all other enteroviruses, work which was hoped would help in the design of safe vaccine strains. We demonstrated that these viruses could be used as expression vectors as well; a patent to this end was granted. Toward the end of my career, a novel genomic deletional pathway by which enteroviruses can persist as an infection long after the acute infection was cleared by the host immune response was discovered and characterized. My final work delved into microbiology with the discovery that a common waste molecule, creatinine, is a broadly effective antibacterial agent which kills both Gram positive and negative bacterial species as well as antibiotic-resistant strains such as MRSA. I maintain ongoing consultative collaborations with colleagues at UNMC as well as at Creighton University and Washburn University.
Education and Training
B.A., University of California, San Diego, 1972
Ph.D., Department of Biology, University of California, San Diego, 1979
Creatinine downregulates TNF-α in macrophage and T cell lines. Riesberg LA, McDonald TL, Wang Y, Chen XM, Holzmer SW, Tracy SM, Drescher KM. Cytokine. 2018 Apr 23;110:29-38.
Mullican JC, Chapman NM, Tracy S. Complete Genome Sequence of the Circular Extrachromosomal Element of Naegleria gruberi Strain EGB Ribosomal DNA. Genome Announcements February 2018 6:e01559-17
Drescher KM, Tracy S. Vanquishing Diabetes. Sci Am. 2018 Jan 16;318(2):54-59
Smithee S, Tracy S, Chapman NM. Mutational disruption of the CRE(2C) in coxsackievirus B3 leads to 5’ terminal genomic deletions. J Virol. 2015 Dec;89(23):11761-72. doi: 10.1128/JVI.01308-15. Epub 2015 Sep 9. PMCID:PMC4645312
McDonald T, Drescher KM, Weber A and Tracy S (2012) Creatinine inhibits bacterial replication. J Antibiotics 2012 Feb 1. doi: 10.1038/ja.2011.131. [Epub ahead of print]
Tracy S, Drescher KM, Jackson JD, Kim K, Kono K. (2010) Enteroviruses, type 1 diabetes and hygiene: a complex relationship. Rev Med Virol. 2010 Mar;20(2):106-16. doi: 10.1002/rmv.639. PMID: 20049905
Chapman N, Kim K-S, Oka K, Kim K, Tracy S (2008) 5' terminal deletions in the genome of a coxsackievirus B2 strain occurred naturally in human heart. Virology 375:480-491. PMCID: PMC2440640.
Tracy S, Drescher KM, Oberste M.S., eds. (2008) The Coxsackie B Viruses. Curr Top Microbiol Immunol. vol. 323. PMID:18357761
Tracy S, Drescher KM, Chapman NM, Kim KS, Carson SD, Pirruccello S, Lane PH, Romero JR, Leser JS. (2002) Toward testing the hypothesis that group B coxsackieviruses (CVB) trigger insulin-dependent diabetes: Inoculating nonobese diabetic mice with CVB markedly lowers diabetes incidence. Journal of Virology. 76 : 12097-12111. PMID:12414951 PMCID: PMC136885.
Carson SD, Chapman NM, Tracy S. (1997) Purification of the putative coxsackievirus B receptor from HeLa cells. Biochemical and Biophysical Research Communications. 233 : 325-328.
Coller BA, Chapman NM, Beck MA, Pallansch MA, Gauntt CJ, Tracy SM. (1990) Echovirus 22 is an atypical enterovirus. Journal of Virology. 64 : 2692-2701. PMID:2159539 PMCID: PMC249448
Semler BL, Johnson VH, Tracy S. (1986) A chimeric plasmid from cDNA clones of poliovirus and coxsackievirus produces a recombinant virus that is temperature-sensitive. Proc. Natl. Acad. Sci. U.S.A. 83 : 1777-81. PMID:3006071 PMCID:PMC323167
Tracy S, Kohne DE. Detection, sizing, and quantitation of polyadenylated ribonucleic acid in the nanogram-picogram range. (1980) Biochemistry. 19 : 3792-3799. PMID:6157400.