CD4 and acute hemorrhagic leukoencephalitis: These results encouraged us to design the present experiment that attempted to treat the immunosenescence, AHL, and cochlear pathology of SAMP1 mice aged 6 months old (after the onset of AHL) and to obtain insight into the development of Tregs and IL-1 receptors on CD4+ T cells, which had been reported to have a relationship to CNS degeneration [10, 12–15].