The School of Molecular and Cellular Biology at the University of Illinois at Urbana-Champaign

Modulation of host cells and tissues by bacterial toxins

Many pathogenic bacteria generate protein toxins that modulate properties of host cells and tissues in order to create a more suitable niche for colonization and, in some cases, to persist for extraordinary periods of time. We are studying the cellular intoxication mechanisms and structure-function relationships of several toxins that, to be successful, must traverse the membrane barrier into human cells. We are especially interested in investigating mechanisms of cellular entry and trafficking, as well as the action of toxins on immune cells. Current model systems in the laboratory include the vacuolating cytotoxin (VacA0 from Helicobacter pylori, the cytolethal distending toxins, and a novel toxin we have recently discovered from Helicobacter pylori.

Molecular and cellular basis of chronic bacterial infections

There is particular interest in understanding mechanisms that allow pathogenic organisms to persist within the host during chronic infection. An emerging paradigm is that persistent organisms are highly adaptive because they have co-evolved with their hosts. As a model system, the Blanke Laboratory is focusing on persistent infection in humans with the gastric pathogen, Helicobacter pylori, which is a significant risk factor for the development of gastric ulcer disease and stomach cancer. Because nearly half the world's population is infected with H. pylori, and because of increasing antibiotic resistance, gastric diseases caused by these micro-organisms are an important biomedical problem. Current research is focused on the contributions of a bacterial toxin (VacA) produced by H. pylori towards remodeling the host environment to create a more suitable niche to colonize and persist for the lifetime of the host in the absence of medical intervention. In addition, there is ongoing research to identify mechanisms by which H. pylori organisms are remodeled to become more adaptive to the stomach. These mechanisms include the capacity of H. pylori to sequester host cholesterol, and to change very rapidly to adapt to changes within the stomach.

Intracellular lifestyles of pathogenic bacteria

We are investigating mechanisms by which pathogenic bacteria not only survive encounters with host immune cells, but are able to exploit these cells by entering, surviving, and in some cases, replicating and escaping. Our model system is Bacillus anthracis, the causative agent of inhalation anthrax. The Blanke laboratory has been investigating the mechanisms by which B. anthracis enters the human lung and exploits the immune response in order to cause disease. Current work centers on the interaction of B. anthracis spores with human cells, and the capacity of B. anthracis to exploit the intracellular phagolysosome environment to germinate and replicate.

Induction of "limited damage" within the host

We are interested in strategies used by pathogenic bacteria to limit damage within the host as a strategy for promoting infection or persistence. We are focusing on mechanisms by which pathogenic organisms are capable of manipulating the human cell cycle through the action of a relatively new family of bacterial toxins, called the cytolethal distending toxins. We are investigating the cellular intoxication mechanisms, structure-function relationships, and evolutionary relationships between these toxins.

Complex Infections

The Blanke Laboratory has undertaken research, associated with the IGB Host-Microbe Systems Theme, to study the dynamic interactions between the host and its commensal as well as pathogenic microbes to elucidate basic processes of disease and commensalism. This research will initially focus on the complex ecosystem of the vaginal microbiota and its impact on health and disease in women.

Development of molecular countermeasures targeting pathogenic bacteria

The ultimate goal of the basic science conducted within the Blanke laboratory is to develop new countermeasures against pathogenic organisms. Current projects, which are highly collaborative, target B. anthracis, the botulinum neurotoxins, the cytolethal distending toxins, VacA, and H. pylori.

Representative Publications

Jain, P., Luo, Z.-Q., & Blanke, S. R. (2011) Helicobacter pylori VacA engages the mitochondrial apoptotic machinery by inducing Drp1-mediated mitochondrial fission, submitted to Proc. Natl. Acad. Sci. U S A.

Han, H., Hemp, J., Pace, L., Ouyang, H., Ganesan, K., Roh, J. H, Daldal, F., Blanke, S. R., & Gennis, R. (2011) Adaptation of aerobic respiration to low O2 environments. Proc. Natl. Acad. Sci. U S A, in press.

Gut, I. M., Blanke, S. R., & van der Donk, W. A. (2011) Mechanism of Inhibition of Bacillus anthracis Spore Outgrowth by the Lantibiotic Nisin, ACS Chemical Biology 6, 744-752. PMID: 21517116 [PubMed - in process].

Whalen, K. L., Tussey, K. B., Blanke, S. R., and Spies, M. A. (2011) Nature of Allosteric Inhibition in Glutamate Racemase: Discovery and Characterization of a Cryptic Inhibitory Pocket Using Atomistic MD Simulations and pK(a) Calculations, J Phys Chem B. 115, 3416-3424. PMCID: PMC3072873.

Gut, I. M., Tamilselvam. B., Prouty, A. M., Stojkovic, B., Czeschin, S., van der Donk, W. A., & Blanke, S. R. (2011) Bacillus anthracis spore interactions with mammalian cells: Relationship between germination state and the outcome of in vitro, BMC Microbiology 11, 46-57. PMCID: PMC3060849.

Nossa, C. W., & Blanke, S. R. (2010) Helicobacter pylori activation of PARP-1: Usurping a versatile regulator of host cellular health, Gut Microbes 1, 1-6. PMCID: PMC3056101.

Gupta, V. R., Wilson, B. A., & Blanke, S. R. (2010) Sphingomyelin is important for the uptake and intracellular trafficking of the Helicobacter pylori VacA, Cellular Microbiology 12, 1517-1533. PMCID: PMC2980835.

Eshraghi, A., Maldonado-Arocho, F. J., Gargi, A., Cardwell, M., Prouty, M. G., Blanke, S. R., & Bradley, K. A. (2010) Cytolethal distending toxin family members are differentially affected by alterations in host glycans and membrane cholesterol. J. Biol. Chem, 285, 18199-18207. PMCID: PMC2881744.

Nossa, C. W., deMurcia, G., Jain, P., Chen, L.- F., Desnoyers, S., & Blanke, S. R. (2009) Activation of the intrinsic catalytic activity of the nuclear factor, poly(ADP-ribose) polymerase-1, by Helicobacter pylori both in vitro and during infection. Proc. Natl. Acad. Sci. U S A 106, 19998-20003.

Blanke, S. R. (2009) Expanding functionality within the Looking Glass Universe. Science 325, 1505-1506.

Lamb A., Yang, X. -D., Tsang, Y. –H., Li, J. –D., Higashi, H., Hatakeyama, M., Peek, R. M., Blanke, S. R., and Chen, L. –F. (2009) Helicobacter pylori CagA stimulates NF-kB by activating TAK1 via TRAF6-mediated K63-ubiquitination. EMBO Reports, 10, 1242-1249.

Gupta, V. R., Wilson, B. A., & Blanke, S. R. (2010) Sphingomyelin is important for the uptake and intracellular trafficking of the Helicobacter pylori VacA, submitted.

Barua, S., McKevitt, M., DeGuisti, K., Hamm, E. E., Larabee, J., Shakir, S., Bryant, K., Spies MA, Reese JG, Dodd D, Pankow KL, Blanke SR, Baudry J. (2009) Determinants of Catalytic Power and Ligand Binding in Glutamate Racemase. J Am Chem Soc. 131, 5274-5284.

Terebiznik, M. R., Raju, D., Vázquez, C. L.,Torbricki, K., Kulkarni, R., Blanke, S. R., Yoshimori, T., Colombo, M. I., & Jones, N. L. (2009) Effect of Helicobacter pylori’s vacuolating cytotoxin on the autophagy pathway in gastric epithelial cells, Autophagy 5, 370-379.

Kim, T. K., Thomas, S. M, Ho, M., Sharma, S., Reich, C. I., Frank, J. A., Yeater, K. M., Biggs, D., Nakamura, N., Stumpf, R., Leigh, S. R., Tapping, R. I., Blanke, S. R., Slauch, J. M., Gaskins, H. R., Weisbaum, J. S., Olsen, G. J., Hoyer, L. L., and Wilson, B. A. (2009) Heterogeneity of vaginal microbial communities within individuals. Journal of Clinical Microbiology 47, 1181-1189.

Koehler, T. M., Blanke, S. R., Dyer, D., Gillaspy, A., & Ballard, J. D. (2009) The Mechanism of Bacillus anthracis Intracellular Germination Requires Multiple and Highly Diverse Genetic Loci. Infection and Immunity 77, 23-31.

Gupta, V. R., Patel, H. K., Kostolansky, S. S., Ballivian, R. A., Eichberg, J., and Blanke, S. R. (2008) Sphingomyelin Functions as a Novel Receptor for Helicobacter pylori VacA, PLoS Pathogens 4, e1000072, 1-12.

Gut, I. M., Prouty, A. M., Ballard, J. D., van der Donk, W. A., & Blanke, S. R. (2008) Inhibition of Bacillus anthracis Spore Outgrowth by Nisin, Antimicrobial Agents and Chemotherapy 52, 4281-4288.

Stojkovic, B., Torres, E. M., Prouty, A. M., Patel, H. K., Koehler. T. M., Ballard, J. D., & Blanke, S. R. (2008) High-throughput, single-cell analysis of macrophage interactions with fluorescently labeled Bacillus anthracis spores. Applied and Environmental Microbiology 74, 5201-5210.

Blanke, S. R., & Cover, T.L. (2008) Helicobacter pylori vacuolating toxin, in Molecular Genetics of Helicobacter, Yamaoka, Y (ed.) Horizon Scientific Press, UK, 87-114.

Ivie, S. E., McClain, M. S., Torres, V. J., Algood, H. M. S., Borden, Lacy, D. B., Yang, R., Blanke, S. R., & Cover, T. L. (2008) A Helicobacter pylori VacA subdomain required for intracellular toxin activity and assembly of functional oligomeric complexes. Infection and Immunity 76, 2843-2851.

Ampapathi, R. S., Lou, D. I., Creath, A. L., Blanke, S. R., & Legge, G. B. (2008) Order - Disorder - order transitions mediate the activation of cholera toxin. Journal of Molecular Biology 377, 748-760.

Dodd, D., Reese J. G., Louer, C. R., Ballard, J. D., Spies, M. A., & Blanke, S. R. (2007) Functional comparison of the two Bacillus anthracis glutamate racemases. Journal of Bacteriology 189, 5265-5275.

McKevitt, M. T, Bryant, K. M., Shakir, S., Larabee, J. L., Blanke, S. R., Lovchik, J., Lyons, C. R, & Ballard, J. D. (2007) Endogenous D-alanine Synthesis and Auto-inhibition of Bacillus anthracis Germination: Effects on in vitro and in vivo Infections. Infection and Immunity 75, 5726-5734.

Ye, D., & Blanke, S. R. (2006) Bacterial toxins as Cellular Modulators, in Molecular Paradigms of Infectious Disease: A Bacterial Perspective, C. A. Nickerson, M. Schurr (eds.), 321-403; Springer Press, US.

Blanke, S. R. (2006) Portals and pathways: Principles of bacterial toxin entry into cells,  Microbe 1, 26-32.

Nossa, C. W., & Blanke, S. R. (2006) Modification of a Mammalian Cell Protein in the Presence of [32P-adenylate] NAD: Evidence for ADP-ribosylation Activity Associated with Helicobacter pylori, Infection and Immunity 74, 3071-3076.

Terebiznik, M. R., Vazquez, C. L., Torbicki, K., Banks, D., Wang, T., Hong, W., Blanke, S. R., Colombo, M. I., & Jones, N. L. (2006) Helicobacter pylori VacA toxin promotes bacterial intracellular survival in gastric epithelial cells. Infection and Immunity 74, 6599-614.

Blanke, S. R. (2005) Micro-managing the Executioner: Pathogen Targeting of Mitochondria, Trends in Microbiology 13, 64-71.

Cover, T.L., & Blanke, S. R. (2005) Helicobacter pylori VacA as a paradigm for toxin multifunctionality, Nature Reviews Microbiology 3, 320-332.

Willhite, D.C., & Blanke, S.R. (2004) Helicobacter pylori Vacuolating cytotoxin enters cells, localizes to the mitochondria, and induces mitochondrial membrane permeability changes correlated to toxin channel activity, Cellular Microbiology 6, 143-154.

Willhite, D.C., Cover, T.L., & Blanke, S.R. (2003) Cellular vacuolation and mitochondrial cytochrome c release are independent outcomes of Helicobacter pylori vacuolating cytotoxin activity that are each dependent on membrane channel formation, J. Biol. Chem. 278, 48204-48209.