Clostridium perfringens epsilon toxin (ETX) is a class B CDC/USDA overlap toxin and a major virulence factor in natural veterinary infections caused by ETX-producing C. perfingens isolates. Currently there are no ETX therapeutics (NIH prefers ETX therapeutics over vaccines because natural ETX-related disease in humans is uncommon). Early steps in ETX action on host cells are poorly understood, which has negatively impacted the development of ETX therapeutics. To remedy the limited understanding of early steps in ETX action and begin exploring the development of ETX therapeutics, the following specific aims will be pursued in this MARGE project (part of Program V, interactions between toxins and host cells): i) Aim 1 will identify the ETX receptor in kidney, brain and lung by expression cloning approaches;ii) Aim 2 will immunolocalize the distribution of the identified receptor in animal and human tissues;iii) Aim 3 will evaluate the pathogenic importance of the identified ETX receptor using antibody blocking approaches, siRNA-mediated reduction of receptor expression, and (if available) receptor knock-out mice;iv) Aim 4 will analyze, by mass spectrometry, the protein composition of ETX complexes formed in the plasma membrane of sensitive host cells to gain further insights into ETX action;v) since previous studies have shown that sialidases can increase ETX binding/activity in MDCK cells, Aim 5 will use isogenic sialidase mutants to evaluate the hypothesis that sialidases similarly potentiate the virulence of ETX-producing isolates and vi) Aim 6 will evaluate the therapeutic potential of ETX receptor decoys. These studies are expected to produce new approaches for therapeutic inhibition of ETX activity, which is a current priority for NIH biodefense activities.
Because of its potency, Clostridium perfringens epsilon toxin (ETX) is listed as a CDC/USDA overlap class B select toxin. Development of ETX therapeutics has been hindered by limited understanding of the early steps in ETX action. This project seeks to understand the early steps in ETX action, particularly the interactions between ETX and its receptor, and exploit this knowledge to develop ETX therapeutics.
|Freedman, John C; Theoret, James R; Wisniewski, Jessica A et al. (2015) Clostridium perfringens type A-E toxin plasmids. Res Microbiol 166:264-79|
|Li, Jihong; McClane, Bruce A (2014) Contributions of NanI sialidase to Caco-2 cell adherence by Clostridium perfringens type A and C strains causing human intestinal disease. Infect Immun 82:4620-30|
|Moy, Ryan H; Gold, Beth; Molleston, Jerome M et al. (2014) Antiviral autophagy restrictsRift Valley fever virus infection and is conserved from flies to mammals. Immunity 40:51-65|
|Cuevas, Christian D; Ross, Susan R (2014) Toll-like receptor 2-mediated innate immune responses against Junín virus in mice lead to antiviral adaptive immune responses during systemic infection and do not affect viral replication in the brain. J Virol 88:7703-14|
|Boyd, Mary Adetinuke; Tennant, Sharon M; Saague, Venant A et al. (2014) Serum bactericidal assays to evaluate typhoidal and nontyphoidal Salmonella vaccines. Clin Vaccine Immunol 21:712-21|
|Su, Yi-Hsuan; Tsegaye, Mikiyas; Varhue, Walter et al. (2014) Quantitative dielectrophoretic tracking for characterization and separation of persistent subpopulations of Cryptosporidium parvum. Analyst 139:66-73|
|Xu, Jie; Cherry, Sara (2014) Viruses and antiviral immunity in Drosophila. Dev Comp Immunol 42:67-84|
|Uzal, Francisco A; Freedman, John C; Shrestha, Archana et al. (2014) Towards an understanding of the role of Clostridium perfringens toxins in human and animal disease. Future Microbiol 9:361-77|
|Weir, Dawn L; Laing, Eric D; Smith, Ina L et al. (2014) Host cell virus entry mediated by Australian bat lyssavirus G envelope glycoprotein occurs through a clathrin-mediated endocytic pathway that requires actin and Rab5. Virol J 11:40|
|Weir, Dawn L; Annand, Edward J; Reid, Peter A et al. (2014) Recent observations on Australian bat lyssavirus tropism and viral entry. Viruses 6:909-26|
Showing the most recent 10 out of 299 publications