PTGS1 and infection: In this study immunohistochemical reactions showed that the immunosuppression induced by methylprednisolone, a synthetic glucocorticoid with a potent and long-acting anti-inflammatory, antiallergic and immunosuppressive action in Acanthamoeba sp.-infected mice caused a decreased in COX-1 detection and decrease in COX-2 immunoreactivity in the lung tissue (especially at the beginning of the infection), but not at 16 dpi and 24 dpi.