The purpose of this project is to study the action of diphtheria toxin at the cellular and molecular level, and to compare and contrast the actin of Pseudomonas exotoxin A, as this toxin has the same cellular target but a different mechanism of entry into the cell. Our major objectives include: 1) Determination of the presence and activity of toxin-specific receptor sites and determination of the process by which diphteria toxin enters cells and its active A fragment reaches the cytosol. 2) Determination of the cellular and molecular basis for the resistance to diphtheria toxin found in some cells and animal species. 3) Elucidation of steps which lead to inhibition of protein synthesis in intoxicated cells. 4) Elucidation of steps in the biosynthesis of diphthamide and determination of its biological role. 5) Extension of our study to include the interaction of toxin-sensitive and toxin-resistant cells with other biologically active agents, including toxins, viruses, hormones, and transport proteins. Investigations will be conducted using cultured mammalian cells and cell-free systems. In our laboratory we have isolated a diverse group of toxin-resistant strains of human and non-human cells which are blocked at different steps in the intoxication process, some at the level of toxin entry and some at the target enzyme elongation factor 2. Utilizing a combination of biochemical and genetic techniques, and techniques of ultrastructural analysis, we have a unique opportunity to investigate not only sensitivity and resistance to microbial toxins, but also regulation of gene expression and cellular function.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI009100-18
Application #
3124497
Study Section
Bacteriology and Mycology Subcommittee 1 (BM)
Project Start
1979-05-01
Project End
1989-04-30
Budget Start
1987-05-01
Budget End
1988-04-30
Support Year
18
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Vermont & St Agric College
Department
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Ackermann, Mark R (2014) Lamb model of respiratory syncytial virus-associated lung disease: insights to pathogenesis and novel treatments. ILAR J 55:4-15
Grosz, Drew D; van Geelen, Albert; Gallup, Jack M et al. (2014) Sucrose stabilization of Respiratory Syncytial Virus (RSV) during nebulization and experimental infection. BMC Res Notes 7:158
Derscheid, Rachel J; van Geelen, Albert; Berkebile, Abigail R et al. (2014) Increased concentration of iodide in airway secretions is associated with reduced respiratory syncytial virus disease severity. Am J Respir Cell Mol Biol 50:389-97
Derscheid, Rachel J; Gallup, Jack M; Knudson, Cory J et al. (2013) Effects of formalin-inactivated respiratory syncytial virus (FI-RSV) in the perinatal lamb model of RSV. PLoS One 8:e81472
Inocencio, N M; Moehring, J M; Moehring, T J (1993) A mutant CHO-K1 strain with resistance to Pseudomonas exotoxin A is unable to process the precursor fusion glycoprotein of Newcastle disease virus. J Virol 67:593-5
Moehring, J M; Inocencio, N M; Robertson, B J et al. (1993) Expression of mouse furin in a Chinese hamster cell resistant to Pseudomonas exotoxin A and viruses complements the genetic lesion. J Biol Chem 268:2590-4
Robertson, B J; Moehring, J M; Moehring, T J (1993) Defective processing of the insulin receptor in an endoprotease-deficient Chinese hamster cell strain is corrected by expression of mouse furin. J Biol Chem 268:24274-7
Foley, B T; Moehring, J M; Moehring, T J (1992) A mutation in codon 717 of the CHO-K1 elongation factor 2 gene prevents the first step in the biosynthesis of diphthamide. Somat Cell Mol Genet 18:227-31
Fendrick, J L; Iglewski, W J; Moehring, J M et al. (1992) Characterization of the endogenous ADP-ribosylation of wild-type and mutant elongation factor 2 in eukaryotic cells. Eur J Biochem 205:25-31
Watson, D G; Moehring, J M; Moehring, T J (1991) A mutant CHO-K1 strain with resistance to Pseudomonas exotoxin A and alphaviruses fails to cleave Sindbis virus glycoprotein PE2. J Virol 65:2332-9

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