Human umbilical cord-derived mesenchymal stem cells ameliorate psoriasis-like dermatitis by suppressing IL-17-producing γδ T cells

Mesenchymal stem cells (MSCs) have shown great potential in treating autoimmune diseases due to their immunomodulatory capability, which has been verified in both animal experiments and clinical trials. Psoriasis is a chronic and remitting immune-related disease. Limited studies have demonstrated that MSCs might be an effective therapeutic approach for managing psoriasis, whose underlying mechanism remains to be elucidated. In our present study, human umbilical cord-derived MSCs (hUC-MSCs) were subcutaneously injected into mice with imiquimod (IMQ)-induced psoriasis-like skin inflammation to explore the feasibility of this cellular therapy. The severity of psoriasis-like dermatitis was evaluated by cumulative psoriasis area and severity index score and epidermal thickness of skin tissue sections. Flow cytometric analysis was utilized to detect T helper cells, regulatory T cells, and gamma delta T cells in skin-draining lymph nodes. Real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were used to assess the expression levels of psoriasisrelated cytokines and chemokines in mouse dorsal skin lesions. We discovered that hUC-MSCs drastically diminished the severity of IMQ-induced psoriasis-like dermatitis and suppressed inflammatory cell response. Although the tail vein injection of hUC-MSCs was also effective, it was correlated with higher mortality owing to pulmonary embolism. By comparison, subcutaneous injection with two million hUC-MSCs was identified to be the optimal therapeutic strategy. Furthermore, we uncovered that hUC-MSCs might repress skin inflammation probably through inhibiting interleukin-17-producing gamma delta T cells. In conclusion, subcutaneous administration of hUC-MSCs might be a promising therapeutic approach for psoriasis. Our findings provide novel insights into the underpinning mechanism of hUC-MSC treatment in the management of psoriasis.

Automated summary

Studies have shown that human umbilical cord-derived MSCs (hUC-MSCs) have the potential to effectively treat psoriasis due to their immunomodulatory capability. Subcutaneous injection of 2 million hUC-MSCs was identified as the optimal therapeutic strategy. Furthermore, hUC-MSCs may suppress skin inflammation by inhibiting interleukin-17-producing gamma delta T cells.