Investigation of Immune Response to Sarcocystis neurona Infection in Horses with Equine Protozoal Myeloencephalitis
In experiment 2, 13 horses were randomly divided into two groups. Baseline neurologic examinations were performed and all horses were confirmed negative for S. neurona antibodies in the CSF and serum. Then, one group with 8 clinically normal seronegative horses was inoculated intravenously with approximately 6000 S. neurona infected autologous leukocytes daily for 14 days. All the challenged horses showed neurologic signs consistent with EPM. PBMCs were isolated from the control and infected horses to determine how S. neurona alters the immune responses based on changes in immune cell subsets and immune function. There were no significant differences in the percentage of CD4 cells in peripheral blood lymphocytes or IFN-Î³ production by CD4 and/or CD8 cells. PMA/I stimulated proliferation responses in PBMCs appeared suppressed compared to that of uninfected controls. Additional studies are necessary to determine the role of CD4 and CD8 cells in disease and protection to S. neurona in horses, as well as to determine the mechanism associated with suppressed in vitro proliferation responses. This project was funded by Patricia Stuart Equine grants and paramutual racing funds from Virginia Tech.
- Masters Theses