This study demonstrates that subcutaneous exposure to zinc oxide nanoparticles exacerbates allergic skin inflammation by enhancing immune cell infiltration and altering T cell homing-related responses. In mouse models of delayed-type hypersensitivity and atopic dermatitis, zinc oxide nanoparticles increased mast cell degranulation, antigen-specific humoral responses, and CD4⁺ T cell accumulation in inflamed skin. Mechanistically, nanoparticle-derived Zn²⁺ induced reactive oxygen species-dependent activation of NF-κB and MAPK signaling, leading to increased expression of the skin-homing chemokine receptors CCR4, CCR8, and CCR10 in T cells. These findings highlight the importance of tissue-specific immune responses when evaluating the safety of zinc oxide nanoparticles, particularly in inflamed or barrier-compromised skin. This study was led by Juhyun Shin, a Ph.D. student in our laboratory, in collaboration with Professor Wan-Seob Cho’s research team through a research project supported by the Ministry of Food and Drug Safety.

Shin, J.*, Park, J.W., Kim, S.Y., Lee, J.A., Kim, S., Jo, M.G., Choi, M.Y., Choi, W.S., Min, K.Y., Noh, G., Choi, Y.H., Cho, W.S., Kim, H.S. Zinc oxide nanoparticles exacerbate allergic skin inflammation via T cell dysregulation and enhancement of immune cell infiltration. Particle and Fibre Toxicology. 2026 Oct 8. doi: 10.1186/s12989-026-00706-4.