Submitted to: ARS Immunology Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 12/3/2003
Publication Date: 12/3/2003
Citation: Harp, J.A., Oesper, J.C., Casey, T. 2003. Oral dosing of mice with Escherichia coli expressing recombinant interferon gamma reduces Cryptosporidium parvum infection [abstract]. ARS Immunology Workshop. p. 59.
Technical Abstract: Cryptosporidium parvum is a protozoan parasite that causes intestinal infection in numerous mammalian species. Previous studies indicate that interferon gamma is critical to resistance to and recovery from C. parvum infection. We electroporated a gene for recombinant murine interferon gamma (rIFN) into a nontoxigenic E. coli strain that expresses the F41 adhesion pilus, allowing it to adhere in the mammalian small intestine (strain 4907.2.1). Groups of mice were treated at 1 day of age with an oral dose of 4907.2.1 expressing rIFN, either alone, or in combination with Lactobacillus brevis and/or killed C. parvum. Controls received phosphate buffered saline. All mice were orally inoculated with 10**3 viable C. parvum oocysts at 7 days of age. Mice were killed at 2 weeks of age, and colon contents examined microscopically for the presence of C. parvum oocysts. The number of oocysts seen per microscopic field was compared between groups. Control mice had a mean of 2.1 oocysts per field. Mice receiving L .brevis, killed C. parvum, and 4907.2.1 had a mean of 1.75 oocysts per field. Mice receiving killed C. parvum and 4907.2.1 had a mean of 1.3 oocysts per field. Mice receiving 4907.2.1 alone had a mean of 1 oocyst per field. While these differences were not statistically significant, there was a clear trend that mice receiving E. coli expressing rIFN were less heavily infected with C. parvum.