@article {818, title = {HEM1 deficiency disrupts mTORC2 and F-actin control in inherited immunodysregulatory disease.}, journal = {Science}, volume = {369}, year = {2020}, month = {2020 07 10}, pages = {202-207}, abstract = {

Immunodeficiency 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 , 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 responses.

}, keywords = {Actins, ADP-Ribosylation Factor 1, CD4-Positive T-Lymphocytes, Cell Proliferation, Cytokines, Humans, Immunologic Deficiency Syndromes, Lymphoproliferative Disorders, Mechanistic Target of Rapamycin Complex 2, Membrane Proteins, Pedigree, Phosphorylation, Wiskott-Aldrich Syndrome Protein Family}, issn = {1095-9203}, doi = {10.1126/science.aay5663}, author = {Cook, Sarah A and Comrie, William A and Poli, M Cecilia and Similuk, Morgan and Oler, Andrew J and Faruqi, Aiman J and Kuhns, Douglas B and Yang, Sheng and Vargas-Hernandez, Alexander and Carisey, Alexandre F and Fournier, Benjamin and Anderson, D Eric and Price, Susan and Smelkinson, Margery and Abou Chahla, Wadih and Forbes, Lisa R and Mace, Emily M and Cao, Tram N and Coban-Akdemir, Zeynep H and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Lupski, James R and Orange, Jordan S and Cuvelier, Geoffrey D E and Al Hassani, Moza and Al Kaabi, Nawal and Al Yafei, Zain and Jyonouchi, Soma and Raje, Nikita and Caldwell, Jason W and Huang, Yanping and Burkhardt, Janis K and Latour, Sylvain and Chen, Baoyu and ElGhazali, Gehad and Rao, V Koneti and Chinn, Ivan K and Lenardo, Michael J} } @article {619, title = {Genetic and mechanistic diversity in pediatric hemophagocytic lymphohistiocytosis.}, journal = {Blood}, volume = {132}, year = {2018}, month = {2018 Jul 05}, pages = {89-100}, abstract = {

The HLH-2004 criteria are used to diagnose hemophagocytic lymphohistiocytosis (HLH), yet concern exists for their misapplication, resulting in suboptimal treatment of some patients. We sought to define the genomic spectrum and associated outcomes of a diverse cohort of children who met the HLH-2004 criteria. Genetic testing was performed clinically or through research-based whole-exome sequencing. Clinical metrics were analyzed with respect to genomic results. Of 122 subjects enrolled over the course of 17 years, 101 subjects received genetic testing. Biallelic familial HLH (fHLH) gene defects were identified in only 19 (19\%) and correlated with presentation at younger than 1 year of age ( < .0001). Digenic fHLH variants were observed but lacked statistical support for disease association. In 28 (58\%) of 48 subjects, research whole-exome sequencing analyses successfully identified likely molecular explanations, including underlying primary immunodeficiency diseases, dysregulated immune activation and proliferation disorders, and potentially novel genetic conditions. Two-thirds of patients identified by the HLH-2004 criteria had underlying etiologies for HLH, including genetic defects, autoimmunity, and malignancy. Overall survival was 45\%, and increased mortality correlated with HLH triggered by infection or malignancy ( < .05). Differences in survival did not correlate with genetic profile or extent of therapy. HLH should be conceptualized as a phenotype of critical illness characterized by toxic activation of immune cells from different underlying mechanisms. In most patients with HLH, targeted sequencing of fHLH genes remains insufficient for identifying pathogenic mechanisms. Whole-exome sequencing, however, may identify specific therapeutic opportunities and affect hematopoietic stem cell transplantation options for these patients.

}, issn = {1528-0020}, doi = {10.1182/blood-2017-11-814244}, author = {Chinn, Ivan K and Eckstein, Olive S and Peckham-Gregory, Erin C and Goldberg, Baruch R and Forbes, Lisa R and Nicholas, Sarah K and Mace, Emily M and Vogel, Tiphanie P and Abhyankar, Harshal A and Diaz, Maria I and Heslop, Helen E and Krance, Robert A and Martinez, Caridad A and Nguyen, Trung C and Bashir, Dalia A and Goldman, Jordana R and Stray-Pedersen, Asbj{\o}rg and Pedroza, Luis A and Poli, M Cecilia and Aldave-Becerra, Juan C and McGhee, Sean A and Al-Herz, Waleed and Chamdin, Aghiad and Coban-Akdemir, Zeynep H and Jhangiani, Shalini N and Muzny, Donna M and Cao, Tram N and Hong, Diana N and Gibbs, Richard A and Lupski, James R and Orange, Jordan S and McClain, Kenneth L and Allen, Carl E} } @article {473, title = {Heterozygous Truncating Variants in POMP Escape Nonsense-Mediated Decay and Cause a Unique Immune Dysregulatory Syndrome.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 06 07}, pages = {1126-1142}, abstract = {

The proteasome processes proteins to facilitate immune recognition and host defense. When inherently defective, it can lead to aberrant immunity resulting in a dysregulated response that can cause autoimmunity and/or autoinflammation. Biallelic or digenic loss-of-function variants in some of the proteasome subunits have been described as causing a primary immunodeficiency disease that manifests as a severe dysregulatory syndrome: chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE). Proteasome maturation protein (POMP) is a chaperone for proteasome assembly and is critical for the incorporation of catalytic subunits into the proteasome. Here, we characterize and describe POMP-related autoinflammation and immune dysregulation disease (PRAID) discovered in two unrelated individuals with a unique constellation of early-onset combined immunodeficiency, inflammatory neutrophilic dermatosis, and autoimmunity. We also begin to delineate a complex genetic mechanism whereby de novo heterozygous frameshift variants in the penultimate exon of POMP escape nonsense-mediated mRNA decay (NMD) and result in a truncated protein that~perturbs proteasome assembly by a dominant-negative mechanism. To our knowledge, this mechanism has not been reported in~any primary immunodeficiencies, autoinflammatory syndromes, or autoimmune diseases. Here, we define a unique hypo- and hyper-immune~phenotype and report an immune dysregulation syndrome caused by frameshift mutations that escape NMD.

}, keywords = {Base Sequence, Cell Line, Endoplasmic Reticulum Stress, Exons, Family, Frameshift Mutation, Genetic Predisposition to Disease, Heterozygote, Humans, Immunologic Deficiency Syndromes, Immunophenotyping, Infant, Newborn, Inflammation, Interferon Type I, Male, Molecular Chaperones, Mutant Proteins, Mutation, Nonsense Mediated mRNA Decay, Phenotype, Proteasome Endopeptidase Complex, RNA, Messenger, Syndrome, Unfolded Protein Response}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.04.010}, author = {Poli, M Cecilia and Ebstein, Fr{\'e}d{\'e}ric and Nicholas, Sarah K and de Guzman, Marietta M and Forbes, Lisa R and Chinn, Ivan K and Mace, Emily M and Vogel, Tiphanie P and Carisey, Alexandre F and Benavides, Felipe and Coban-Akdemir, Zeynep H and Gibbs, Richard A and Jhangiani, Shalini N and Muzny, Donna M and Carvalho, Claudia M B and Schady, Deborah A and Jain, Mahim and Rosenfeld, Jill A and Emrick, Lisa and Lewis, Richard A and Lee, Brendan and Zieba, Barbara A and K{\"u}ry, S{\'e}bastien and Kr{\"u}ger, Elke and Lupski, James R and Bostwick, Bret L and Orange, Jordan S} }