Cholea is a pandemic disease caused by V. cholerae in which cholera toxin (CT) cause life-threatening diarrhea. Enterotoxigenic E. coli and other enteroxic enteric bacteria cause diarrheal disease closely related to cholera. Highly effective vaccines against these diseases are not yet available. Our long range goals are to understand the structure and function of cholera toxin (CT) at the molecular level and to exploit the remarkable properties of holotoxin diseases.
Specific Aim 1 will use biochemical, genetic, cell biological, and structural methods to characterize features of CT-A and CT-B that determine the biological actives of CT. These studies will analyze interactions between CT-A and CT-B that are essential for assembly of CT, determine structure of conformation-dependent epitopes of CT-B that elicit neutralizing antibodies, investigate the activation pathway for CT-A and determine the structure of active CT-A1, explore the role of specific gangliosides in intracellular trafficking of CT and related enterotoxins, and develop assays for translocation of CT-A across intracellular membranes.
Specific Aim 2 will evaluate holotxin-like chimeras, in which microbial protective antigens replace the A1 domain of CT, as model oral factors of Vibrio Cholerae, will be tested for ability to induce protective anti-toxic and anti-bacterial immunity against cholera; and chimeras that incorporate Streptococcus pneumoniae PspA, which express conserved protective epitopes, will be tested for their ability to induce cross-protective immunity against pneumococci of multiple capsular serotypes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI031940-09
Application #
2871502
Study Section
Special Emphasis Panel (ZRG5-BM-2 (01))
Project Start
1992-02-01
Project End
2002-01-31
Budget Start
1999-02-01
Budget End
2000-01-31
Support Year
9
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Colorado Denver
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
065391526
City
Aurora
State
CO
Country
United States
Zip Code
80045
Jobling, Michael G (2016) The chromosomal nature of LT-II enterotoxins solved: a lambdoid prophage encodes both LT-II and one of two novel pertussis-toxin-like toxin family members in type II enterotoxigenic Escherichia coli. Pathog Dis 74:
Day, Charles A; Baetz, Nicholas W; Copeland, Courtney A et al. (2015) Microtubule motors power plasma membrane tubulation in clathrin-independent endocytosis. Traffic 16:572-90
Banerjee, Tuhina; Taylor, Michael; Jobling, Michael G et al. (2014) ADP-ribosylation factor 6 acts as an allosteric activator for the folded but not disordered cholera toxin A1 polypeptide. Mol Microbiol 94:898-912
Price, Gregory A; Holmes, Randall K (2014) Immunizing adult female mice with a TcpA-A2-CTB chimera provides a high level of protection for their pups in the infant mouse model of cholera. PLoS Negl Trop Dis 8:e3356
Price, Gregory A; McFann, Kim; Holmes, Randall K (2013) Immunization with cholera toxin B subunit induces high-level protection in the suckling mouse model of cholera. PLoS One 8:e57269
Arifuzzaman, Mohammad; Rashu, Rasheduzzaman; Leung, Daniel T et al. (2012) Antigen-specific memory T cell responses after vaccination with an oral killed cholera vaccine in Bangladeshi children and comparison to responses in patients with naturally acquired cholera. Clin Vaccine Immunol 19:1304-11
Price, Gregory A; Holmes, Randall K (2012) Evaluation of TcpF-A2-CTB chimera and evidence of additive protective efficacy of immunizing with TcpF and CTB in the suckling mouse model of cholera. PLoS One 7:e42434
Jobling, Michael G; Holmes, Randall K (2012) Type II heat-labile enterotoxins from 50 diverse Escherichia coli isolates belong almost exclusively to the LT-IIc family and may be prophage encoded. PLoS One 7:e29898
Jobling, Michael G; Yang, Zhijie; Kam, Wendy R et al. (2012) A single native ganglioside GM1-binding site is sufficient for cholera toxin to bind to cells and complete the intoxication pathway. MBio 3:
Korotkov, Konstantin V; Johnson, Tanya L; Jobling, Michael G et al. (2011) Structural and functional studies on the interaction of GspC and GspD in the type II secretion system. PLoS Pathog 7:e1002228

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