Human umbilical cord mesenchymal stem cells increase interleukin-9 production of CD4⁺ T cells

Mesenchymal stem cells (MSC) are able to differentiate into cells of multiple lineage, and additionally act to modulate the immune response. Interleukin (IL)-9 is primarily produced by cluster of differentiation (CD)4⁺ T cells to regulate the immune response. The present study aimed to investigate the effect of human umbilical cord derived-MSC (UC-MSC) on IL-9 production of human CD4⁺ T cells. It was demonstrated that the addition of UC-MSC to the culture of CD4⁺ T cells significantly enhanced IL-9 production by CD4⁺ T cells. Transwell experiments suggested that UC-MSC promotion of IL-9 production by CD4⁺ T cells was dependent on cell-cell contact. Upregulated expression of CD106 was observed in UC-MSC co-cultured with CD4⁺ T cells, and the addition of a blocking antibody of CD106 significantly impaired the ability of UC-MSC to promote IL-9 production by CD4⁺ T cells. Therefore, the results of the present study demonstrated that UC-MSC promoted the generation of IL-9 producing cells, which may be mediated, in part by CD106. The findings may act to expand understanding and knowledge of the immune modulatory role of UC-MSC.