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CPB 697 RESEARCH SEMINAR
DEPARTMENT OF COMPARATIVE PATHOBIOLOGY
Tracy H. Vemulapalli, DVM, MS Graduate Student in Lab Animal Medicine Department of Comparative Pathobiology Purdue University
“Creation Of A
Bovine Chimeric Mouse:
Thursday, October 26, 2006 VPTH 112 3:30 p.m.
ASTRACT: Johne’s disease, caused by Mycobacterium avium subspecies paratuberculosis, is a chronic debilitating disease of cattle that is responsible for significant losses in productivity. Animals are often infected as calves and may not show clinical signs for 2 or more years. Malabsorption and wasting occurs due to the significant granulomatous lesions present along the intestinal tract. Understanding the pathogenesis of Johne’s disease can lead to better diagnostic, therapeutic, and preventive strategies. Studies involving cattle require a vast input of resources. The lack of a defined genetic background and microbial status in bovine experimental subjects can lead to increased variability in data and confound results. Therefore, it would be beneficial to have a small animal (rodent) model for Johne’s disease. Currently, however, there is no rodent model for Johne’s disease that accurately replicates the pathology and immune responses seen in the bovine host. Our ultimate goal is to create bovine chimeric mice using fetal calf immune cells; such mice can serve as a more suitable animal model for Johne’s disease research. In this pilot study, we looked at the feasibility of engrafting fetal immune cells into two immunodeficient strains of mice, C.B-17 scid/bg and C57BL/6 rag2-/pfp- mice. Both of these mouse strains lack mature T- and B-lymphocytes, making them less likely to reject xenografts. For each mouse strain, a specific experimental protocol was designed to enable successful engraftment of fetal bovine immune cells. The ability of the engrafted mice to mount a bovine primary and secondary immune response to T-dependent antigen was tested using Brucella abortus vaccine strain RB51. Current progress on this project will be discussed |