Project description:Few monogenic causes for severe manifestations of common allergic diseases have been identified. Through next-generation sequencing on a cohort of patients with severe atopic dermatitis with and without comorbid infections, we found eight individuals, from four families, with novel heterozygous mutations in CARD11, which encodes a scaffolding protein involved in lymphocyte receptor signaling. Disease improved over time in most patients. Transfection of mutant CARD11 expression constructs into T cell lines demonstrated both loss-of-function and dominant-interfering activity upon antigen receptor-induced activation of nuclear factor-κB and mammalian target of rapamycin complex 1 (mTORC1). Patient T cells had similar defects, as well as low production of the cytokine interferon-γ (IFN-γ). The mTORC1 and IFN-γ production defects were partially rescued by supplementation with glutamine, which requires CARD11 for import into T cells. Our findings indicate that a single hypomorphic mutation in CARD11 can cause potentially correctable cellular defects that lead to atopic dermatitis.
Project description:Activation of NFkB pathway by CARD11 Cy3-labelled untreated sample and Cy5-labelled treated sample were hybridized to a Lymphochip microarray.
Project description:Atopic dermatitis (AD) is the most common inflammatory skin disease, with high unmet need for new therapies that are safe for chronic use. Emerging data suggest that TH2-cytokines play important roles in a variety of allergic and atopic conditions, including asthma and AD. In early phase clinical trials, dupilumab (a fully human monoclonal antibody against IL-4Rα that potently blocks IL-4 and IL-13 signaling) rapidly and markedly improved clinical measures in adults with either asthma (with elevated eosinophil counts) or moderate-to-severe AD. The pathomechanisms that may be impacted by IL-4/13 blockade in these disease settings have not yet been characterized in detail. Transcriptome analyses in pre- and post-treatment skin biopsies from patients with moderate-to-severe AD treated with dupilumab or placebo in two completed clinical trials
Project description:In order to investigate the molecular mechanism of CARD11 in immune cell system, we applied the RNA-seq analysis using RNA isolated from WT and CARD11 mutant (E134G and K215M) mouse spleen B cells. By comparing the transcriptome files, we found some different expressed gene involved in due to the CARD11 point mutation and in vitro RT-PCR had confirmed this result.
Project description:BACKGROUND:Caspase activation and recruitment domain 11 (CARD11) encodes a scaffold protein in lymphocytes that links antigen receptor engagement with downstream signaling to nuclear factor ?B, c-Jun N-terminal kinase, and mechanistic target of rapamycin complex 1. Germline CARD11 mutations cause several distinct primary immune disorders in human subjects, including severe combined immune deficiency (biallelic null mutations), B-cell expansion with nuclear factor ?B and T-cell anergy (heterozygous, gain-of-function mutations), and severe atopic disease (loss-of-function, heterozygous, dominant interfering mutations), which has focused attention on CARD11 mutations discovered by using whole-exome sequencing. OBJECTIVES:We sought to determine the molecular actions of an extended allelic series of CARD11 and to characterize the expanding range of clinical phenotypes associated with heterozygous CARD11 loss-of-function alleles. METHODS:Cell transfections and primary T-cell assays were used to evaluate signaling and function of CARD11 variants. RESULTS:Here we report on an expanded cohort of patients harboring novel heterozygous CARD11 mutations that extend beyond atopy to include other immunologic phenotypes not previously associated with CARD11 mutations. In addition to (and sometimes excluding) severe atopy, heterozygous missense and indel mutations in CARD11 presented with immunologic phenotypes similar to those observed in signal transducer and activator of transcription 3 loss of function, dedicator of cytokinesis 8 deficiency, common variable immunodeficiency, neutropenia, and immune dysregulation, polyendocrinopathy, enteropathy, X-linked-like syndrome. Pathogenic variants exhibited dominant negative activity and were largely confined to the CARD or coiled-coil domains of the CARD11 protein. CONCLUSION:These results illuminate a broader phenotypic spectrum associated with CARD11 mutations in human subjects and underscore the need for functional studies to demonstrate that rare gene variants encountered in expected and unexpected phenotypes must nonetheless be validated for pathogenic activity.
Project description:Atopic dermatitis (AD) is the most common inflammatory skin disease, with high unmet need for new therapies that are safe for chronic use. Emerging data suggest that TH2-cytokines play important roles in a variety of allergic and atopic conditions, including asthma and AD. In early phase clinical trials, dupilumab (a fully human monoclonal antibody against IL-4R? that potently blocks IL-4 and IL-13 signaling) rapidly and markedly improved clinical measures in adults with either asthma (with elevated eosinophil counts) or moderate-to-severe AD. The pathomechanisms that may be impacted by IL-4/13 blockade in these disease settings have not yet been characterized in detail. Transcriptome analyses in pre- and post-treatment skin biopsies from patients with moderate-to-severe AD treated with dupilumab or placebo in two completed clinical trials 18 Patients with AD treated with dupilumab or placebo. 28 biopsies in lesional (LS) Skin (16 pre-treatment and 12 post-treatment). 12 biopsies in non-lesional (NL) Skin (7 pre-treatment and 5 post treatment)
Project description:PurposeActivating germline mutations in CARD11 have recently been linked to a rare genetic disorder associated with congenital B cell lymphocytosis. We describe a patient with a similar clinical phenotype who had a de novo germline G123D CARD11 mutation.MethodsWhole exome sequencing was performed on DNA from the patient and his biological parents. Laboratory studies examined characteristics of the patient's B and T lymphocytes. A CARD11 cDNA containing the mutation was transfected into a lymphocyte cell line to gain an understanding of its function. RNA sequencing was performed on samples from the patient and from patients with alternate germline CARD11 mutations and differential gene expression analysis was performed.ResultsThe patient had a decade-long history of severe polyclonal B lymphocytosis in the 20,000-90,000 lymphocytes/mm(3) range, which was markedly exacerbated by EBV infection and splenectomy at different times. He had a heterozygous germline CARD11 mutation causing a G123D amino acid substitution, which was demonstrated to induce NF-κB activation in unstimulated lymphocytes. In contrast to previous patients with CARD11 mutations, this patient's B cells exhibited higher expression of several cell cycle progression genes, as well as enhanced proliferation and improved survival following B cell receptor stimulation.ConclusionsThis is the third reported germline and first de novo CARD11 mutation shown to cause congenital B cell lymphocytosis. The mutation was associated with a dramatically greater lymphocytosis than in previously described cases, disproportionate to the level of constitutive NF-κB activation. However, comparative review of the patient's clinical history, combined with additional genomic and functional analyses, underscore other important variables that may affect pathophysiology or regulate mutant CARD11 function in B cell proliferation and disease. We now refer to these patients as having BENTA disease (B cell Expansion with NF-κB and T cell Anergy).