Anti-CD1d treatment suppresses immunogenic maturation of lung dendritic cells dependent on lung invariant natural killer T cells in asthmatic mice.

• Anti-CD1d treatment suppress Th2 cell responses in asthma by suppresses immunogenic maturation of LDCs. • Anti-CD1d treatment lowers the abundance and activation of lung iNKT cells in asthma. • The influences of anti-CD1d treatment in LDCs of asthma were dependent on lung iNKT cells. • The influences of anti-CD1d treatment in LDCs of asthma were relevant to the downregulation of CD40L expression on lung iNKT cells. Our previous findings show that invariant natural killer T (iNKT) cells can promote immunogenic maturation of lung dendritic cells (LDCs) to enhance Th2 cell responses in asthma. It has been accepted that recognition of glycolipid antigens presented by CD1d molecules by the T cell receptors of iNKT cells leads to iNKT cell activation. Therefore, we examine the immunoregulatory influences of anti-CD1d treatment on Th2 cell response and immunogenic maturation of LDCs and subsequently explored whether these influences were dependent on lung iNKT cells in asthmatic mice. We discovered that in wild-type mice sensitized and challenged with house dust mite or ovalbumin (OVA), anti-CD1d treatment inhibited Th2 cell response and immunogenic maturation of LDCs. LDCs from asthmatic mice with anti-CD1d treatment had a markedly decreased influence on Th2 cell responses in vivo and in vitro. Furthermore, anti-CD1d treatment reduced the abundance and activation of lung iNKT cells in asthmatic mice. Moreover, in asthmatic iNKT cell-deficient Jα18-/- mice, anti-CD1d treatment did not influence Th2 cell responses and immunogenic maturation of LDCs. Meanwhile, the quantity of CD40L+ iNKT cells in asthmatic mice was significant decreased by anti-CD1d treatment. Finally, the inhibition of anti-CD1d treatment on LDC immunogenic maturation and Th2 cell responses in asthmatic mice was reversed by anti-CD40 treatment. Our data suggest that anti-CD1d treatment can suppress Th2 cell responses through inhibiting immunogenic maturation of LDCs dependent on lung iNKT cells, which could be partially related to the downregulation of CD40L expression on lung iNKT cells in asthmatic mice. [ABSTRACT FROM AUTHOR]