UNC93B1 interacts with the calcium sensor STIM1 for efficient antigen cross-presentation in dendritic cells

作者：Maschalidi Sophia; Nunes Hasler Paula; Nascimento Clarissa R; Sallent Ignacio; Lannoy Valerie; Garfa Traore Meriem; Cagnard Nicolas; Sepulveda Fernando E; Vargas Pablo; Lennon Dumenil Ana Maria; van Endert Peter; Capiod Thierry; Demaurex Nicolas; Darrasse Jeze Guillaume; Manoury Benedicte^*

来源：Nature Communications, 2017, 8(1): 1640.

DOI：10.1038/s41467-017-01601-5

Dendritic cells (DC) have the unique ability to present exogenous antigens via the major histocompatibility complex class I pathway to stimulate naive CD8+ T cells. In DCs with a non-functional mutation in Unc93b1 (3d mutation), endosomal acidification, phagosomal maturation, antigen degradation, antigen export to the cytosol and the function of the store-operated-Ca2+-entry regulator STIM1 are impaired. These defects result in compromised antigen cross-presentation and anti-tumor responses in 3d-mutated mice. Here, we show that UNC93B1 interacts with the calcium sensor STIM1 in the endoplasmic reticulum, a critical step for STIM1 oligomerization and activation. Expression of a constitutively active STIM1 mutant, which no longer binds UNC93B1, restores antigen degradation and cross-presentation in 3d-mutated DCs. Furthermore, ablation of STIM1 in mouse and human cells leads to a decrease in cross-presentation. Our data indicate that the UNC93B1 and STIM1 cooperation is important for calcium flux and antigen cross-presentation in DCs.

• 出版日期2017-11-21