الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The pigmentary disorder vitiligo is intricately linked to a multifaceted etiology characterized by T-cell mediated autoimmune responses targeting cutaneous melanocytes. Recent research implicates microbial dysbiosis as a contributing factor in the development of vitiligo. Despite the complexity of its origins, effective vitiligo treatments are in high demand, necessitating the exploration of innovative therapeutic approaches. In this study, we investigated the potential of exopolysaccharides (EPS) derived from Bacillus subtilis commensals as a microbiome-based therapy.
Using the vitiligo-prone h3TA2 mouse model, we administered weekly intraperitoneal injections of EPS over an 18-week period. The progression of depigmentation was monitored throughout the treatment duration, and immune responses were assessed at the study endpoint. Remarkably, our findings demonstrate that EPS treatment significantly attenuated the rate of depigmentation. Analysis of the skin revealed a notable reduction in the abundance of cutaneous T cells, particularly within the CD8+ cytotoxic T cell subset, while regulatory T cells exhibited a relatively higher presence in the treated mice.
Furthermore, the treatment induced an increase in the number of splenic M2 macrophages, indicative of a shift in systemic cytokine patterns towards a type 2
cytokine profile. Notably, splenocytes obtained from EPS-treated mice exhibited diminished responsiveness to cognate tyrosinase peptide, as evidenced by a restricted release of interferon-gamma (IFN-γ) and other inflammatory cytokines. Collectively, these results underscore the interference of B. subtilis EPS with T-cell mediated depigmentation in the h3TA2 mouse model of vitiligo.
In conclusion, our study proposes that EPS isolated from B. subtilis holds promise as a novel therapeutic agent for vitiligo, offering a potential avenue for the development of innovative treatment strategies targeting the intricate immune mechanisms underlying this dermatological disorder.