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Carrie L. Shaffer, PhD


Office: (859) 218-1168
Office: 435 Gluck Equine Research Center


  • Assistant Professor, Department of Veterinary Science
Other Affiliation(s)
  • Microbiology, Immunology & Molecular Genetics - Adjunct Faculty


The Shaffer lab aims to understand how bacteria use the specialized type IV secretion system (T4SS) to evade host defense mechanisms and survive within diverse niches. Specifically, our research program focuses on (i) determining how the T4SS apparatus assembles in response to target cell contact, (ii) defining the architecture and topology of diverse T4SS machineries, (iii) understanding molecular mechanisms that trigger cargo transport across the bacterial cell envelope, and (iv) investigating how translocated substrates interact with the host cell to drive pathogenesis. The lab primarily explores secretion system biology in the gastric bacterium Helicobacter pylori.

Selected Publications

Varga, MG, CR Wood, J Butt, ME Ryan, W-C You, K Pan, T Waterboer, M Epplein, and CL Shaffer (2021). Immunostimulatory membrane proteins potentiate H. pylori-induced carcinogenesis by enabling CagA translocation. Gut Microbes 13: 1-13. (PMID: 33382363)

Chang YW*, Shaffer CL*, Rettberg LA, Ghosal D, Jensen GJ (2018). In vivo structures of the Helicobacter pylori cag type IV secretion system. Cell Reports 23(3):673-681. (PMID: 29669273) *Equal First Authorship

Shaffer CL, EW Zhang, AG Dudley, BREA Dixon, KR Guckes, EJ Breland, DP Casella, HMS Algood, D Clayton, M Hadjifrangiskou (2016). Purine biosynthesis metabolically constrains vacuolar escape and intracellular survival of uropathogenic E. coli. Infection and Immunity 85(1):e00471-16. (PMID: 27795353)

Shaffer CL, JAD Good, S Kumar, KS Krishnan, JA Gaddy, JT Loh, J Chappell, F Almqvist, TL Cover, M Hadjifrangiskou (2016). Peptidomimetic small molecules disrupt type IV secretion system activity in diverse bacterial pathogens. mBio 7(2):e00221-16. (PMID: 27118587)

Varga MG, CL Shaffer, JC Sierra, G Suarez, MB Piazuelo, ME Whitaker, J Romero-Gallo, US Krishna, A Delgado, MA. Gomez, JAD Good, F Almqvist, EP Skaar, P Correa, KT Wilson, M Hadjifrangiskou, RM Peek, Jr. (2016). Pathogenic Helicobacter pylori strains translocate DNA and activate TLR9 via the cancer-associated cag type IV secretion system. Oncogene 35(48):6262-6269. (PMID: 27157617)

Kodaman N, A Pazos, BG Schneider, MB Piazuelo, RM Mera, R Sobota, L Sicinschi, CL Shaffer, J Romero-Gallo, T Saltet de Sablet, RH Harder, LE Bravo, RM Peek, Jr., KT Wilson, TL Cover, SM Williams, P Correa (2014). Human and Helicobacter pylori co-evolution shapes the risk of gastric disease. PNAS 111(4):1455-60. (PMID: 24474772)

Shaffer, CL, JA Gaddy, JT Loh, EM Johnson, S Hill, EE Hennig, MS McClain, WH McDonald, TL Cover (2011). Helicobacter pylori exploits a unique repertoire of type IV secretion system components for pilus assembly at the bacteria-host cell interface. PLoS Pathogens 7(9):e1002237. (PMID: 21909278)

Saltet de Sablet, T*, MB Piazuelo*, CL Shaffer*, BG Schneider, M Asim, R Chaturvedi, LE Bravo, L Sicinschi, AG Delgado, RM Mera, DA Israel, J Romero-Gallo, RM Peek, Jr., TL Cover, P Correa, KT Wilson (2011) Phylogeographic origin of Helicobacter pylori is a determinant of gastric cancer risk. Gut 60(9):1189-95 (PMID: 21357593) *Equal First Authorship