Fetal thymus graft prevents age-related hearing loss and up regulation of the IL-1 receptor type II gene in CD4(+) T cells.

We found that rejuvenation of the recipient immunity by inoculation of young CD4(+) T cells or a fetal thymus graft led to down regulation of the interleukin 1 receptor type II (IL-1R2) gene in CD4(+) T cells and reduced age-related hearing loss and degeneration of the spiral ganglion in SAMP1 mice, a murine model of human senescence. Our studies on the relationship between age-related systemic immune dysfunctions and neurodegeneration mechanisms open up new avenues of treatment of neurosenescence, including presbycusis, for which there is no effective therapy.