Ò. Expósito, M. Monzón, V. Vidal, A. Gallego, S. Ruiz, P. Riera, D. Luna, X. Zhao, M. Mas, M. Gibert, L. Cano, S. Laplana, T. Ruiz, L. Facchini, R. Ferreira, A. Guirado
Urban lifestyles expose the skin to a sustained mix of indoor and outdoor pollutants that drive chronic low-grade inflammation, barrier dysfunction and immune hyperreactivity, producing sensitive, reactive skin. Conventional soothing strategies relieve symptoms without addressing the underlying immune dysregulation. This paper introduces the concept of a cosmetic tolerogen (an active that re-educates the skin’s immune system to restore tolerance instead of suppressing it) and evaluates Toleroxyl™, a recombinant human GM-CSF produced in a plant biofactory.
Biological activity was assessed in a reconstructed human epidermis model containing Langerhans cells exposed to a standardised Indoor Pollution Challenge. Inflammatory markers, tolerogenic mediators and barrier proteins were quantified and benchmarked against dexamethasone. Efficacy was confirmed in two independent, randomised, double-blind, placebo-controlled clinical studies in volunteers with hyperreactive skin.
In vitro, the active normalised pollution-induced inflammatory markers, enhanced the tolerogenic factors RELB, SOX4 and TGF-â, and restored barrier proteins. In vivo, it reduced skin redness by up to 65.3 %, improved dermatologist-assessed erythema and functional signs, and lowered pro-inflammatory cytokines.
By re-educating Langerhans cells towards tolerance, the active restores immune balance, barrier function and visible comfort, defining a new immunomodulatory category for sensitive-skin care.
