Dr. Hai Qi and his colleagues of Lab of Immunological Dynamics of IITU reported a new mechanism of how regulatory T cells suppress the functions of dendritic cells independent of MHC class II on the Journal of Experimental Medicine in January, 2017.

Regulatory T (Treg) cells are essential for peripheral homeostasis and known to target and suppress the functions dendritic cells (DCs). One important mechanism is through prolonged interaction between antigen-specific Treg cells and DCs that down-regulates the co-stimulatory capacity of DCs. However, the dynamics and TCR specificities of such Treg cell–DC interaction and its relevance to the suppressive outcomes for individual DCs have not been clarified. To gain insights into the underlying cellular events in vivo, Qi's group analyzed individual Treg cell–DC interaction events in lymph nodes by intravital microscopy. Their results show that, upon exposure to interleukin-2, Treg cells formed prolonged adhesive contact with DCs, independent of antigen or MHC recognition, which significantly suppressed the contemporaneous interaction of the same DCs with antigen-specific conventional T cells and impaired T cell priming. Therefore, Treg cells may function in part as feedback regulators in inflammatory milieu, by suppressing local DCs and interrupting immune activation in a contact-dependent and class II MHC-independent manner.

The PhD student from Peking-Tsinghua-NIBS program, Jiacong Yan is the first author of this research. The PhD student Bo Liu from School of Medicine also contributed to this work.

The original article could be found from the following link: link http://jem.rupress.org/content/214/2/319.long