Cook, Sarah AComrie, William APoli, CeciliaSimiluk, MorganOler, Andrew JFaruqi, Aiman JKuhns, Douglas BYang, ShengVargas-Hernández, AlexanderCarisey, Alexandre FFournier, BenjaminAnderson, D EricPrice, SusanSmelkinson, MargeryAbou Chahla, WadihForbes, Lisa RMace, Emily MCao, Tram NCoban-Akdemir, Zeynep HJhangiani, Shalini N2021-10-282021-10-282020Science 2020 Jul 10;369(6500):202-207http://hdl.handle.net/11447/4963Donna M Muzny, Richard A Gibbs, James R Lupski , Jordan S Orange, Geoffrey D E Cuvelier , Moza Al Hassani , Nawal Al Kaabi , Zain Al Yafei , Soma Jyonouchi , Nikita Raje , Jason W Caldwell , Yanping Huang , Janis K Burkhardt , Sylvain Latour , Baoyu Chen , Gehad ElGhazali , V Koneti Rao , Ivan K Chinn , Michael J LenardoImmunodeficiency often coincides with hyperactive immune disorders such as autoimmunity, lymphoproliferation, or atopy, but this coincidence is rarely understood on a molecular level. We describe five patients from four families with immunodeficiency coupled with atopy, lymphoproliferation, and cytokine overproduction harboring mutations in NCKAP1L, which encodes the hematopoietic-specific HEM1 protein. These mutations cause the loss of the HEM1 protein and the WAVE regulatory complex (WRC) or disrupt binding to the WRC regulator, Arf1, thereby impairing actin polymerization, synapse formation, and immune cell migration. Diminished cortical actin networks caused by WRC loss led to uncontrolled cytokine release and immune hyperresponsiveness. HEM1 loss also blocked mechanistic target of rapamycin complex 2 (mTORC2)-dependent AKT phosphorylation, T cell proliferation, and selected effector functions, leading to immunodeficiency. Thus, the evolutionarily conserved HEM1 protein simultaneously regulates filamentous actin (F-actin) and mTORC2 signaling to achieve equipoise in immune responsesen-USArticle