3rd Annual BMRP Investigator Meeting - Abstract
Clostridium perfringens as a Novel Therapeutic Vehicle in Inflammatory Bowel Disease
Scott Plevy1,2,a, Fengling Li1,2, Yue Chen3, Shaival Dave1,2, Jeremy Tilstra1,2, Paul Robbins4, Bruce McClane4 and Phalguni Gupta3
1Department of Medicine, 2Department of Immunology, 3Department of Infectious Diseases and Microbiology and 4Department of Molecular Genetics and Biochemistry, University of Pittsburgh (Pittsburgh, Pennsylvania, U.S.A.)
The goal of this project is to create a novel biologic therapeutic approach, particularly targeted to Crohn’s disease using a normal constituent of the enteric bacterial flora, Clostridium perfringens (CP). CP is better known as a cause of self-limited food borne disease. In humans, vegetative CP sporulates in the small intestine. In the case of pathogenic strains, spores lyse in the terminal ileum, releasing large amounts of CP enterotoxin (cpe). We have genetically engineered CP, replacing the plasmid-based cpe gene with HIV and SIV peptides. These peptides are delivered directly to the distal small bowel in rodents and generate mucosal immune responses in vivo.
Recombinant CP that express interleukin-10 (IL-10) (IL-10 CP) have been successfully engineered. Sporulating IL-10 CP produce immunoreactive IL-10 detectable by ELISA and Western blot. IL-10 is biologically active as determined in an IL-12 inhibition assay. In vivo studies to optimize delivery of IL-10 by CP to the terminal ileum of mice are ongoing. IL-10 CP will then be tested as a therapeutic modality in IL-10 deficient (-/-) mice with enterocolitis and in SAMP1/YitFc mice with chronic ileitis. In fact, CP may be most amenable to the delivery of short anti-inflammatory peptides. One such molecule, an IkB kinase inhibitor NEMO binding domain peptide, linked to a cationic peptide transduction domain (PTD5-NBD) is currently being cloned into the cpe plasmid. This 25 amino acid peptide, administered (10 mg/kg IP) to IL-10-/- mice for two weeks ameliorates colitis (colitis score 0.3 vs. 1.3 with vehicle, p<0.05, n=4 per group) and inhibits IL-12 p40 expression in vivo in splenocytes and intestinal explants.
CP 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 CP. Therefore, CP holds promise as a novel therapeutic modality in Crohn’s disease.
aPrincipal Investigator