@article {771, title = {Defective glycosylation and multisystem abnormalities characterize the primary immunodeficiency XMEN disease.}, journal = {J Clin Invest}, volume = {130}, year = {2020}, month = {2020 01 02}, pages = {507-522}, abstract = {

X-linked immunodeficiency with magnesium defect, EBV infection, and neoplasia (XMEN) disease are caused by deficiency of the magnesium transporter 1 (MAGT1) gene. We studied 23 patients with XMEN, 8 of whom were EBV naive. We observed lymphadenopathy (LAD), cytopenias, liver disease, cavum septum pellucidum (CSP), and increased CD4-CD8-B220-TCRαβ+ T cells (αβDNTs), in addition to the previously described features of an inverted CD4/CD8 ratio, CD4+ T lymphocytopenia, increased B cells, dysgammaglobulinemia, and decreased expression of the natural killer group 2, member D (NKG2D) receptor. EBV-associated B cell malignancies occurred frequently in EBV-infected patients. We studied patients with XMEN and patients with autoimmune lymphoproliferative syndrome (ALPS) by deep immunophenotyping (32 immune markers) using time-of-flight mass cytometry (CyTOF). Our analysis revealed that the abundance of 2 populations of naive B cells (CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4++CD10+CD38+ and CD20+CD27-CD22+IgM+HLA-DR+CXCR5+CXCR4+CD10-CD38-) could differentially classify XMEN, ALPS, and healthy individuals. We also performed glycoproteomics analysis on T lymphocytes and show that XMEN disease is a congenital disorder of glycosylation that affects a restricted subset of glycoproteins. Transfection of MAGT1 mRNA enabled us to rescue proteins with defective glycosylation. Together, these data provide new clinical and pathophysiological foundations with important ramifications for the diagnosis and treatment of XMEN disease.

}, keywords = {Antigens, CD, Autoimmune Lymphoproliferative Syndrome, Cation Transport Proteins, CD4-CD8 Ratio, Female, Glycosylation, Humans, Magnesium Deficiency, Male, X-Linked Combined Immunodeficiency Diseases}, issn = {1558-8238}, doi = {10.1172/JCI131116}, author = {Ravell, Juan C and Matsuda-Lennikov, Mami and Chauvin, Samuel D and Zou, Juan and Biancalana, Matthew and Deeb, Sally J and Price, Susan and Su, Helen C and Notarangelo, Giulia and Jiang, Ping and Morawski, Aaron and Kanellopoulou, Chrysi and Binder, Kyle and Mukherjee, Ratnadeep and Anibal, James T and Sellers, Brian and Zheng, Lixin and He, Tingyan and George, Alex B and Pittaluga, Stefania and Powers, Astin and Kleiner, David E and Kapuria, Devika and Ghany, Marc and Hunsberger, Sally and Cohen, Jeffrey I and Uzel, Gulbu and Bergerson, Jenna and Wolfe, Lynne and Toro, Camilo and Gahl, William and Folio, Les R and Matthews, Helen and Angelus, Pam and Chinn, Ivan K and Orange, Jordan S and Trujillo-Vargas, Claudia M and Franco, Jose Luis and Orrego-Arango, Julio and Guti{\'e}rrez-Hincapi{\'e}, Sebastian and Patel, Niraj Chandrakant and Raymond, Kimiyo and Patiroglu, Turkan and Unal, Ekrem and Karakukcu, Musa and Day, Alexandre Gr and Mehta, Pankaj and Masutani, Evan and De Ravin, Suk S and Malech, Harry L and Altan-Bonnet, Gr{\'e}goire and Rao, V Koneti and Mann, Matthias and Lenardo, Michael J} } @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} }