Interleukin-10 Enhances γδ T Cell Development in the Murine Fetal Thymus

We have investigated the ability of interleukin-10 (IL-10) to modulate murine intrathymic T cell differentiation using a fetal thymic organ culture (FTOC) model. Addition of as little as 11 ng of recombinant murine IL-10 (mIL-10) per day produced a significant increase in the proportion and number of γδTCR+ cells in 4-day cultures derived from Gestational Day 14 mice, compared to vehicle-treated cultures. This effect occurred in the absence of any changes in other parameters of intrathymic T cell development. The increase in the γδ-TCR population included an enlargement of the Vγ2+, Vγ3+, and Vδ4+ populations. The enhancement of γδ cell development was not observed in 2- or 7-day cultures, indicating the time dependence of this response. Overall, these results reveal that IL-10 treatment of FTOC can affect murine γδ T cell development and suggest that this cytokine may mediate specific events in the generation of the γδ T cell repertoire.