Research projects in the Cover laboratory are focused on investigating molecular mechanisms by which pathogenic bacteria cause disease in humans. We are particularly interested in the bacterium Helicobacter pylori and its role as a causative agent of stomach cancer.  H. pylori is the only bacterial pathogen that commonly causes cancer in humans and has been designated as a Class I carcinogen by the World Health Organization. H. pylori colonizes the stomach in about half of the global population, and stomach cancer is the third leading cause of cancer mortality worldwide.

Examples of projects currently underway in the lab include (i) investigation of two secreted H. pylori toxins (VacA and CagA), (ii) investigation of the H. pylori type IV secretion system that delivers CagA into gastric epithelial cells, (iii) investigation of dietary composition as a determinant of gastric cancer risk, and (iv) identification of strain-specific H. pylori constituents that contribute to gastric cancer pathogenesis. 

Lab website:



The following timeline graph is generated from all co-authored publications.

Featured publications are shown below:

  1. Bacterial Energetic Requirements for Helicobacter pylori Cag Type IV Secretion System-Dependent Alterations in Gastric Epithelial Cells. Lin AS, Dooyema SDR, Frick-Cheng AE, Harvey ML, Suarez G, Loh JT, McDonald WH, McClain MS, Peek RM, Cover TL (2020) Infect Immun 88(2)
    › Primary publication · 31712269 (PubMed) · PMC6977121 (PubMed Central)
  2. Structure of the Cag type IV secretion system. Chung JM, Sheedlo MJ, Campbell AM, Sawhney N, Frick-Cheng AE, Lacy DB, Cover TL, Ohi MD (2019) Elife
    › Primary publication · 31210639 (PubMed) · PMC6620104 (PubMed Central)
  3. Helicobacter pylori Vacuolating Toxin and Gastric Cancer. McClain MS, Beckett AC, Cover TL (2017) Toxins (Basel) 9(10)
    › Primary publication · 29023421 (PubMed) · PMC5666363 (PubMed Central)
  4. Helicobacter pylori Diversity and Gastric Cancer Risk. Cover TL (2016) mBio 7(1): e01869-15
    › Primary publication · 26814181 (PubMed) · PMC4742704 (PubMed Central)
  5. Molecular and Structural Analysis of the Helicobacter pylori cag Type IV Secretion System Core Complex. Frick-Cheng AE, Pyburn TM, Voss BJ, McDonald WH, Ohi MD, Cover TL (2016) mBio 7(1): e02001-15
    › Primary publication · 26758182 (PubMed) · PMC4725015 (PubMed Central)
  6. Human and Helicobacter pylori coevolution shapes the risk of gastric disease. Kodaman N, Pazos A, Schneider BG, Piazuelo MB, Mera R, Sobota RS, Sicinschi LA, Shaffer CL, Romero-Gallo J, de Sablet T, Harder RH, Bravo LE, Peek RM, Wilson KT, Cover TL, Williams SM, Correa P (2014) Proc Natl Acad Sci U S A 111(4): 1455-60
    › Primary publication · 24474772 (PubMed) · PMC3910595 (PubMed Central)