Bacterial enterotoxins are members of a class of proteins known as superantigens (SAgs) that have lethal activity because they elicit massive T cell activation, leading to release of inflammatory molecules such as TNF-alpha. Most of the known bacterial SAgs are expressed by Staphylococcus aureus and Streptococcus pyogenes. These include select agents of bioterrorism such as staphylococcal enterotoxin B (SEB) that has been considered by the U.S. military as a major threat for incapacitation and lethality. SAgs activate T cells by cross-linking T cell receptor Vbeta regions with class II MHC molecules on another cell. The proposed project will develop soluble Vbeta receptors that can neutralize enterotoxins and will involve the laboratories of four scientists that have extensive experience in structural, functional, and clinical studies of SAgs: David Kranz, University of Illinois; Patrick Schlievert, U. Minnesota; Roy Mariuzza, U. Maryland; Sina Bavari, U.S. Army. The receptor engineering components of the project will use yeast display technology to generate high-affinity antagonists against a panel of SAgs (in the order of priority: SEB, TSST-1, SEC3, SpeA, SpeC). Based on the low LD50 values (approximately 1 mu g) of SEB predicted for humans, it is very likely that low picomolar affinity agents will be required for effective neutralization. In previous work, we snowed that high-affinity, soluble receptor domains (12 KDa) engineered by yeast display inhibited the in vitro activity of SEB and SEC3. As evidence that Vbeta:SAg interactions can be engineered to low picomolar affinities, we recently generated a panel of Vbeta8 mutants with KD values for SEB from 40 to 90 pM. The present project will further develop these, and other soluble Va receptors, as therapeutics.
The specific aims are to: 1) To engineer and characterize Vbeta regions that bind with high-affinity to SAgs: SEB, TSST-1, SEC3, SpeA, and SpeC, 2) To generate Vbeta immunoglobulin fusions of the agents from aim 1 and to characterize their binding properties and serum lifetimes in mice, 3) To test the ability of soluble Vbeta-Ig fusions to inhibit activity of SAgs in vitro and to neutralize the toxins in animal models. The models will include """"""""humanized"""""""" class II MHC/CD4 transgenic mice (including an aerosol model of exposure) and rabbits, which resemble human SAg-mediated diseases in symptoms and toxicity. The strategies developed here to engineer very high-affinity neutralizing receptors and to increase their serum lifetimes should be directly translatable to the development of antagonists against other toxins that are considered potential agents of bioterrorism.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI064611-02
Application #
7012349
Study Section
Special Emphasis Panel (ZRG1-DDR (01))
Program Officer
Van de Verg, Lillian L
Project Start
2005-02-01
Project End
2010-01-31
Budget Start
2006-02-01
Budget End
2007-01-31
Support Year
2
Fiscal Year
2006
Total Cost
$324,427
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820
Mattis, D M; Spaulding, A R; Chuang-Smith, O N et al. (2013) Engineering a soluble high-affinity receptor domain that neutralizes staphylococcal enterotoxin C in rabbit models of disease. Protein Eng Des Sel 26:133-42
Stone, Jennifer D; Chervin, Adam S; Aggen, David H et al. (2012) T cell receptor engineering. Methods Enzymol 503:189-222
Bonsor, Daniel A; Postel, Sandra; Pierce, Brian G et al. (2011) Molecular basis of a million-fold affinity maturation process in a protein-protein interaction. J Mol Biol 411:321-8
Cho, Sangwoo; Swaminathan, Chittoor P; Bonsor, Daniel A et al. (2010) Assessing energetic contributions to binding from a disordered region in a protein-protein interaction . Biochemistry 49:9256-68
Strandberg, Kristi L; Rotschafer, Jessica H; Vetter, Sara M et al. (2010) Staphylococcal superantigens cause lethal pulmonary disease in rabbits. J Infect Dis 202:1690-7
Wang, Ningyan; Mattis, Daiva M; Sundberg, Eric J et al. (2010) A single, engineered protein therapeutic agent neutralizes exotoxins from both Staphylococcus aureus and Streptococcus pyogenes. Clin Vaccine Immunol 17:1781-9
John, Chandy C; Niermann, Micah; Sharon, Bazak et al. (2009) Staphylococcal toxic shock syndrome erythroderma is associated with superantigenicity and hypersensitivity. Clin Infect Dis 49:1893-6
Richman, Sarah A; Kranz, David M; Stone, Jennifer D (2009) Biosensor detection systems: engineering stable, high-affinity bioreceptors by yeast surface display. Methods Mol Biol 504:323-50
Yang, Xi; Buonpane, Rebecca A; Moza, Beenu et al. (2008) Neutralization of multiple staphylococcal superantigens by a single-chain protein consisting of affinity-matured, variable domain repeats. J Infect Dis 198:344-8
Wang, Limin; Zhao, Yiwei; Li, Zhong et al. (2007) Crystal structure of a complete ternary complex of TCR, superantigen and peptide-MHC. Nat Struct Mol Biol 14:169-71

Showing the most recent 10 out of 15 publications