IN VITRO SUPPRESSED IMMUNE RESPONSE IN HORSES EXPERIMENTALLY INFECTED WITH SARCOCYSTIS NEURONA.
June 27th, 2008 | by admin |IN VITRO SUPPRESSED IMMUNE RESPONSE IN HORSES EXPERIMENTALLY INFECTED WITH SARCOCYSTIS NEURONA.
Equine protozoal myeloencephalitis, due to Sarcocystis neurona infection, is one of the most common neurologic diseases in horses in the United States. The mechanisms by which most horses resist disease, as well as the possible mechanisms by which the immune system may be suppressed in horses that develop EPM are not known. Therefore, the objectives of this study were to determine whether horses experimentally infected with S. neurona developed suppressed immune responses. Thirteen horses that were negative for S. neurona antibodies in serum and cerebrospinal fluid (CSF) were randomly assigned to control (n=5) or infected (n=8) treatment groups. Neurologic exams and cerebrospinal fluid analyses were performed prior to and following Sarcocystis neurona infection. Prior to and at multiple time points following infection, immune parameters were determined. All 8 S. neurona infected horses developed clinical signs consistent with EPM, as well as had S. neurona antibodies in the serum and CSF. Infected and control horses had increased percentages (P < 0.05) of B-cells at 28 days post-infection. Infected horses had significantly decreased (P < 0.05) proliferation responses as measured by thymidine incorporation to non-specific mitogens phorbol myristate acetate (PMA) and ionomycin (I) as soon as 2 days post-infection.
Witonsky S, Ellison S, Yang J, Gogal R, Lawler H, Suzuki Y, Sriranganathan N, Andrews F, Ward D, Lindsay D.