Immunohistochemical phenotyping of macrophages and T lymphocytes infiltrating in peripheral nerve lesions of dourine-affected horses

Abstract

Dourine is a deadly protozoan disease in equids caused by infection with Trypanosoma equiperdum . Neurological signs in the later stage of infection may be caused by peripheral polyneuritis and related axonal degeneration. This neuritis involves T lymphocytes, B lymphocytes, and macrophages, and is observed in cases without obvious neurological signs. However, the pathogenesis of neuritis remains unclear. We identified M2 macrophages and CD8 T cells as the predominant phenotypes in neuritis of dourine-affected horses with or without neurological signs. In contrast, the populations of M1 macrophages and CD4 T cells were small. This result indicates that inflammation was chronic and suggests that dourine-associated neuritis occurs at the early stage of infection.

Establishment of a Chronic Trypanosoma Equiperdum Infection Model in Mice

“…Infected horses manifest various clinical signs, such as edema of the external genitalia, skin plaques, and neurological signs 5 . Pathological examinations of infected horses revealed that these clinical signs are caused by in ammation and edema of the genital organs, dermatitis, and peripheral polyneuritis, respectively [6][7][8][9] . However, the pathogenesis of dourine remains largely unknown.…”