Prevention of Hearing Loss by Alteration of the Systemic Immune System

Abstract

Although congenital sensorineural hearing loss (SHL) in the bilateral coch-leae mainly results from genetic abnormalities, chronic SHL progressing in later life is often influenced by systemic immune disturbances, including au-toimmunity, chronic inflammation, and immunosenescence. We have investigated the relationship between the inner ear and systemic immunity and reviewed the possibilities to prevent SHL, including autoimmune SHL and age-related SHL. We also demonstrated two lymphocyte populations, inter-leukin 1 receptor type II (IL-1R2)-positive T cells (T1R2) and naturally occurring regulatory T cells (nTregs) in CD4 + T cells, which increase with aging , suppress host immune function and promote organ degeneration. Alterations in systemic immunity by fewer microbial antigen challenges in the living environment, elimination of immune suppressive lymphocytes, or immune rejuvenation with a reconstituted thymus may contribute not only to renew the cochlear function in SHL, but also to extend the healthy life of functional organs in a vigorous and youthful body, one of humanity's greatest dreams.