# MAMMALIAN CELL RESPONSE TO DIPHTHERIA TOXIN

> **NIH NIH R01** · UNIVERSITY OF VERMONT & ST AGRIC COLLEGE · 1988 · $273,038

## Abstract

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.

## Key facts

- **NIH application ID:** 3124498
- **Project number:** 5R01AI009100-19
- **Recipient organization:** UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
- **SAM.gov UEI:** Z94KLERAG5V9
- **Principal Investigator:** THOMAS J MOEHRING
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $273,038
- **Award type:** 5
- **Project period:** 1979-05-01 → 1989-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3124498

## Citation

> US National Institutes of Health, RePORTER application 3124498, MAMMALIAN CELL RESPONSE TO DIPHTHERIA TOXIN (5R01AI009100-19). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3124498. Licensed CC0.

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