Scientific Abstract

Proposal No.    IBD-0110
Principal Investigator:  Scott E. Plevy, M.D.
Applicant Organization:  University of Pittsburgh (Pennsylvania, U.S.A.)
Project Title: Clostridium perfringens as a novel therapeutic vehicle in inflammatory bowel disease
Period of Award:  August 1, 2004 - January 31, 2006

The goal of this proposal is to create a novel biologic therapeutic system targeted to Crohn’s disease using a normal constituent of the enteric bacterial flora.  Enteric bacterial species such as Lactococcus, Lactobacillus, and Streptococcus have been genetically engineered to express cytokines and antigens to alter mucosal immune responses.  By this approach, anti-inflammatory modalities can be delivered directly to the intestinal mucosa, thereby minimizing the potential for systemic toxicity. Clostridium perfringens is a normal constituent of the enteric flora.  It is better known as an important cause of self-limited food borne disease.  In humans, vegetative C. perfringens sporulate in the small intestine.  In the case of pathogenic organisms, spores lyse in the terminal ileum, releasing large amounts of C. perfringens enterotoxin (cpe).

We have genetically engineered C. perfringens, replacing the plasmid-based cpe gene with HIV and SIV peptides.  These peptides are delivered directly to the distal small bowel in rodents.  In this proposal, we will generate recombinant C. perfringens that produce the anti-inflammatory cytokine interleukin-10 (IL-10) during sporulation.  We will demonstrate that C. perfringens can make bioactive IL-10.  Delivery of bacterially expressed IL-10 in high quantities to the terminal ileum of mice will be optimized.  Finally, we will test C. perfringens as a therapeutic modality in IL-10 deficient mice with enterocolitis and in SAMP1/YitFc mice with chronic ileitis. 

C. perfringens may pose several significant advantages over other bacteriotherapeutic approaches:  1) molecules can be delivered specifically to the distal small bowel; 2) these molecules are produced at extremely high local concentrations and; 3) no significant immune responses occur against C. perfringens.  If successful, these proof of concept experiments will lead to non-human primate and human studies to evaluate C. perfringens as a novel therapeutic modality in Crohn’s disease.