Semaphorin3A Promotes the Development of Nickel Allergy

Abstract Metal allergy is one of the typical immune disorders encountered during the application of dental/medical materials and has a highly complex pathogenic mechanism. Semaphorin 3A (Sema3A), a member of the semaphorin family, is reported to be involved in various immune disorders. However, its role in metal allergy has not been clarified yet. Herein, we show that Sema3A promoted nickel (Ni) allergy by mediating tumor necrosis factor-alpha (TNF-α) production and mitogen-activated protein kinase (MAPK) activation in keratinocytes. Sema3A was upregulated in NiCl2-stimulated mouse keratinocytes and in Ni allergy-induced mouse ear tissue. TNF-α production and MAPK activation were altered when Sema3A was suppressed in keratinocytes. The specific deletion of Sema3A in keratinocytes alleviated Ni allergy and regulated the macrophage polarization towards an anti-inflammatory direction. Our results demonstrate that Sema3A promotes the development of metal allergy and should be explored as a potential target for the prevention and treatment of metal allergy.