@article {783, title = {Disease-associated CTNNBL1 mutation impairs somatic hypermutation by decreasing nuclear AID.}, journal = {J Clin Invest}, volume = {130}, year = {2020}, month = {2020 08 03}, pages = {4411-4422}, abstract = {

Patients with common variable immunodeficiency associated with autoimmune cytopenia (CVID+AIC) generate few isotype-switched B cells with severely decreased frequencies of somatic hypermutations (SHMs), but their underlying molecular defects remain poorly characterized. We identified a CVID+AIC patient who displays a rare homozygous missense M466V mutation in β-catenin-like protein 1 (CTNNBL1). Because CTNNBL1 binds activation-induced cytidine deaminase (AID) that catalyzes SHM, we tested AID interactions with the CTNNBL1 M466V variant. We found that the M466V mutation interfered with the association of CTNNBL1 with AID, resulting in decreased AID in the nuclei of patient EBV-transformed B cell lines and of CTNNBL1 466V/V Ramos B cells engineered to express only CTNNBL1 M466V using CRISPR/Cas9 technology. As a consequence, the scarce IgG+ memory B cells from the CTNNBL1 466V/V patient showed a low SHM frequency that averaged 6.7 mutations compared with about 18 mutations per clone in healthy-donor counterparts. In addition, CTNNBL1 466V/V Ramos B cells displayed a decreased incidence of SHM that was reduced by half compared with parental WT Ramos B cells, demonstrating that the CTNNBL1 M466V mutation is responsible for defective SHM induction. We conclude that CTNNBL1 plays an important role in regulating AID-dependent antibody diversification in humans.

}, keywords = {Amino Acid Substitution, Apoptosis Regulatory Proteins, B-Lymphocytes, Cell Line, Child, Preschool, Common Variable Immunodeficiency, Cytidine Deaminase, Female, Homozygote, Humans, Immunologic Memory, Mutation, Missense, Nuclear Proteins, Somatic Hypermutation, Immunoglobulin}, issn = {1558-8238}, doi = {10.1172/JCI131297}, author = {Kuhny, Marcel and Forbes, Lisa R and {\c C}akan, Elif and Vega-Loza, Andrea and Kostiuk, Valentyna and Dinesh, Ravi K and Glauzy, Salom{\'e} and Stray-Pedersen, Asbjorg and Pezzi, Ashley E and Hanson, I Celine and Vargas-Hernandez, Alexander and Xu, Mina LuQuing and Coban-Akdemir, Zeynep H and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Lupski, James R and Chinn, Ivan K and Schatz, David G and Orange, Jordan S and Meffre, Eric} } @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 {721, title = {Novel Heterozygous Mutation in Is Associated With Early Onset CVID and a Functional Defect in NK Cells Complicated by Disseminated CMV Infection and Severe Nephrotic Syndrome.}, journal = {Front Pediatr}, volume = {7}, year = {2019}, month = {2019}, pages = {303}, abstract = {

Nuclear factor kappa-B subunit 2 (NF-κB2/p100/p52), encoded by (MIM: 164012) belongs to the NF-κB family of transcription factors that play a critical role in inflammation, immunity, cell proliferation, differentiation and survival. Heterozygous C-terminal mutations in have been associated with early-onset common variable immunodeficiency (CVID), central adrenal insufficiency and ectodermal dysplasia. Only two previously reported cases have documented decreased natural killer (NK) cell cytotoxicity, and little is known about the role of NF-κB2 in NK cell maturation and function. Here we report a 13-year-old female that presented at 6 years of age with a history of early onset recurrent sinopulmonary infections, progressive hair loss, and hypogamaglobulinemia consistent with a clinical diagnosis of CVID. At 9 years of age she had cytomegalovirus (CMV) pneumonia that responded to ganciclovir treatment. Functional NK cell testing demonstrated decreased NK cell cytotoxicity despite normal NK cell numbers, consistent with a greater susceptibility to systemic CMV infection. Research exome sequencing (ES) was performed and revealed a novel heterozygous nonsense mutation in (c.2611C>T, p.Gln871) that was not carried by either of her parents. The variant was Sanger sequenced and confirmed to be in the patient. At age 12, she presented with a reactivation of the systemic CMV infection that was associated with severe and progressive nephrotic syndrome with histologic evidence of pedicellar effacement and negative immunofluorescence. To our knowledge, this is the third NF-κB2 deficient patient in which an abnormal NK cell function has been observed, suggesting a role for non-canonical NF-κB2 signaling in NK cell cytotoxicity. NK cell function should be assessed in patients with mutations in the non-canonical NF-κB pathway to explore the risk for systemic viral infections that may lead to severe complications and impact patient survival. Similarly NF-κB2 should be considered in patients with combined immunodeficiency who have aberrant NK cell function. Further studies are needed to characterize the role of NF-κB2 in NK cell cytotoxic function.

}, issn = {2296-2360}, doi = {10.3389/fped.2019.00303}, author = {Aird, Alejandra and Lagos, Macarena and Vargas-Hernandez, Alexander and Posey, Jennifer E and Coban-Akdemir, Zeynep and Jhangiani, Shalini and Mace, Emily M and Reyes, Anaid and King, Alejandra and Cavagnaro, Felipe and Forbes, Lisa R and Chinn, Ivan K and Lupski, James R and Orange, Jordan S and Poli, Maria Cecilia} } @article {622, title = {Mutations in PI3K110δ cause impaired natural killer cell function partially rescued by rapamycin treatment.}, journal = {J Allergy Clin Immunol}, volume = {142}, year = {2018}, month = {2018 Aug}, pages = {605-617.e7}, abstract = {

BACKGROUND: Heterozygous gain-of-function mutations in PI3K110δ lead to lymphadenopathy, lymphoid hyperplasia, EBV and cytomegalovirus viremia, and sinopulmonary infections.

OBJECTIVE: The known role of natural killer (NK) cell function in the control of EBV and cytomegalovirus prompted us to investigate the functional and phenotypic effects of PI3K110δ mutations on NK cell subsets and cytotoxic function.

METHODS: Mutations in patients were identified by using whole-exome or targeted sequencing. We performed NK cell phenotyping and functional analysis of patients{\textquoteright} cells using flow cytometry, standard Cr cytotoxicity assays, and quantitative confocal microscopy.

RESULTS: PI3K110δ mutations led to an altered NK cell developmental phenotype and cytotoxic dysfunction. Impaired NK cell cytotoxicity was due to decreased conjugate formation with susceptible target cells and abrogated activation of cell machinery required for target cell killing. These defects were restored partially after initiation of treatment with rapamycin in 3 patients.

CONCLUSION: We describe novel NK cell functional deficiency caused by PI3K110δ mutation, which is a likely contributor to the severe viremia observed in these patients. Rapamycin treatment partially restores NK cell function, providing a further rationale for its use in patients with this disease.

}, issn = {1097-6825}, doi = {10.1016/j.jaci.2017.11.042}, author = {Ruiz-Garc{\'\i}a, Raquel and Vargas-Hernandez, Alexander and Chinn, Ivan K and Angelo, Laura S and Cao, Tram N and Coban-Akdemir, Zeynep and Jhangiani, Shalini N and Meng, Qingchang and Forbes, Lisa R and Muzny, Donna M and Allende, Luis M and Ehlayel, Mohammed S and Gibbs, Richard A and Lupski, James R and Uzel, Gulbu and Orange, Jordan S and Mace, Emily M} } @article {507, title = {Novel STAT1 Gain-of-Function Mutation Presenting as Combined Immunodeficiency.}, journal = {J Clin Immunol}, volume = {38}, year = {2018}, month = {2018 Oct}, pages = {753-756}, abstract = {

}, issn = {1573-2592}, doi = {10.1007/s10875-018-0554-3}, author = {Hartono, Stella P and Vargas-Hernandez, Alexander and Ponsford, Mark J and Chinn, Ivan K and Jolles, Stephen and Wilson, Keith and Forbes, Lisa R} } @article {215, title = {Early-onset lymphoproliferation and autoimmunity caused by germline STAT3 gain-of-function mutations.}, journal = {Blood}, volume = {125}, year = {2015}, month = {2015 Jan 22}, pages = {591-9}, abstract = {

Germline loss-of-function mutations in the transcription factor signal transducer and activator of transcription 3 (STAT3) cause immunodeficiency, whereas somatic gain-of-function mutations in STAT3 are associated with large granular lymphocytic leukemic, myelodysplastic syndrome, and aplastic anemia. Recently, germline mutations in STAT3 have also been associated with autoimmune disease. Here, we report on 13 individuals from 10 families with lymphoproliferation and early-onset solid-organ autoimmunity associated with 9 different germline heterozygous mutations in STAT3. Patients exhibited a variety of clinical features, with most having lymphadenopathy, autoimmune cytopenias, multiorgan autoimmunity (lung, gastrointestinal, hepatic, and/or endocrine dysfunction), infections, and short stature. Functional analyses demonstrate that these mutations confer a gain-of-function in STAT3 leading to secondary defects in STAT5 and STAT1 phosphorylation and the regulatory T-cell compartment. Treatment targeting a cytokine pathway that signals through STAT3 led to clinical improvement in 1 patient, suggesting a potential therapeutic option for such patients. These results suggest that there is a broad range of autoimmunity caused by germline STAT3 gain-of-function mutations, and that hematologic autoimmunity is a major component of this newly described disorder. Some patients for this study were enrolled in a trial registered at www.clinicaltrials.gov as $\#$NCT00001350.

}, keywords = {Adolescent, Adult, Autoimmune Diseases, Child, Child, Preschool, Female, Genetic Diseases, Inborn, Humans, Infant, Lymphoproliferative Disorders, Male, Mutation, Phosphorylation, STAT1 Transcription Factor, STAT3 Transcription Factor, STAT5 Transcription Factor, T-Lymphocytes, Regulatory}, issn = {1528-0020}, doi = {10.1182/blood-2014-09-602763}, author = {Milner, Joshua D and Vogel, Tiphanie P and Forbes, Lisa and Ma, Chi A and Stray-Pedersen, Asbj{\o}rg and Niemela, Julie E and Lyons, Jonathan J and Engelhardt, Karin R and Zhang, Yu and Topcagic, Nermina and Roberson, Elisha D O and Matthews, Helen and Verbsky, James W and Dasu, Trivikram and Vargas-Hernandez, Alexander and Varghese, Nidhy and McClain, Kenneth L and Karam, Lina B and Nahmod, Karen and Makedonas, George and Mace, Emily M and Sorte, Hanne S and Perminow, G{\o}ri and Rao, V Koneti and O{\textquoteright}Connell, Michael P and Price, Susan and Su, Helen C and Butrick, Morgan and McElwee, Joshua and Hughes, Jason D and Willet, Joseph and Swan, David and Xu, Yaobo and Santibanez-Koref, Mauro and Slowik, Voytek and Dinwiddie, Darrell L and Ciaccio, Christina E and Saunders, Carol J and Septer, Seth and Kingsmore, Stephen F and White, Andrew J and Cant, Andrew J and Hambleton, Sophie and Cooper, Megan A} }