Typhoid fever is a major global health concern, with ongoing occurring outbreaks in some developing countries. The causative agent of typhoid fever is the gram-negative bacterium, Salmonella Typhi. It was recently discovered that S. Typhi produces an unusual toxin known as typhoid toxin. The goal of this research program is to generate the first B cell epitope map of typhoid toxin, with a particular focus on identification of regions associated with the onset of toxin-neutralizing antibodies.
In Specific Aim 1 we will generate a collection of murine monoclonal antibodies (MAbs) against all of the three components of typhoid toxin, CdtB, PltA and PltB and characterize them to identify potent MAbs by performing ELISA, cell-based toxin-neutralization assays, competition ELISA, pepscan analysis, mutagenesis, and surface plasmon resonance.
In Specific Aim 2 a select number of toxin-neutralizing MAbs generated in Aim 1 will be evaluated for the ability to passively protect mice against lethal dose typhoid toxin challenge. We will test whether the MAbs with the most potent toxin-neutralizing activity in vitro are also protective in vivo. Additionally, we will begin to define the mechanism(s) by which the most potent MAbs neutralize typhoid toxin in vitro. The MAbs generated as part of this study will be powerful tools for more detailed mechanistic studies to better understand the biology of typhoid toxin and may even have potential applications for therapeutics uses in humans.

Public Health Relevance

Salmonella enterica serovar Typhi is the causative agent of the disease typhoid fever, which results in 21 million illnesses and more than 200,000 deaths every year. Multidrug-resistant strains of S. Typhi have become prevalent in typhoid outbreak areas, implying a potential increase of the mortality rate in the future. Understanding how antibodies can neutralize typhoid toxin will open the door for the development of new strategies to treat typhoid fever.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Small Research Grants (R03)
Project #
1R03AI135767-01
Application #
9434338
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Alexander, William A
Project Start
2017-12-15
Project End
2019-11-30
Budget Start
2017-12-15
Budget End
2018-11-30
Support Year
1
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Cornell University
Department
Microbiology/Immun/Virology
Type
Schools of Veterinary Medicine
DUNS #
872612445
City
Ithaca
State
NY
Country
United States
Zip Code
14850