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1.
Mol Ther Methods Clin Dev ; 32(1): 101183, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38282895

ABSTRACT

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic disorder caused by mutations in the FOXP3 gene, required for generation of regulatory T (Treg) cells. Loss of Treg cells leads to immune dysregulation characterized by multi-organ autoimmunity and early mortality. Hematopoietic stem cell (HSC) transplantation can be curative, but success is limited by autoimmune complications, donor availability and/or graft-vs.-host disease. Correction of FOXP3 in autologous HSC utilizing a homology-directed repair (HDR)-based platform may provide a safer alternative therapy. Here, we demonstrate efficient editing of FOXP3 utilizing co-delivery of Cas9 ribonucleoprotein complexes and adeno-associated viral vectors to achieve HDR rates of >40% in vitro using mobilized CD34+ cells from multiple donors. Using this approach to deliver either a GFP or a FOXP3 cDNA donor cassette, we demonstrate sustained bone marrow engraftment of approximately 10% of HDR-edited cells in immune-deficient recipient mice at 16 weeks post-transplant. Further, we show targeted integration of FOXP3 cDNA in CD34+ cells from an IPEX patient and expression of the introduced FOXP3 transcript in gene-edited primary T cells from both healthy individuals and IPEX patients. Our combined findings suggest that refinement of this approach is likely to provide future clinical benefit in IPEX.

2.
Mol Ther ; 31(8): 2472-2488, 2023 08 02.
Article in English | MEDLINE | ID: mdl-37147803

ABSTRACT

Engineered T cells represent an emerging therapeutic modality. However, complex engineering strategies can present a challenge for enriching and expanding therapeutic cells at clinical scale. In addition, lack of in vivo cytokine support can lead to poor engraftment of transferred T cells, including regulatory T cells (Treg). Here, we establish a cell-intrinsic selection system that leverages the dependency of primary T cells on IL-2 signaling. FRB-IL2RB and FKBP-IL2RG fusion proteins were identified permitting selective expansion of primary CD4+ T cells in rapamycin supplemented medium. This chemically inducible signaling complex (CISC) was subsequently incorporated into HDR donor templates designed to drive expression of the Treg master regulator FOXP3. Following editing of CD4+ T cells, CISC+ engineered Treg (CISC EngTreg) were selectively expanded using rapamycin and maintained Treg activity. Following transfer into immunodeficient mice treated with rapamycin, CISC EngTreg exhibited sustained engraftment in the absence of IL-2. Furthermore, in vivo CISC engagement increased the therapeutic activity of CISC EngTreg. Finally, an editing strategy targeting the TRAC locus permitted generation and selective enrichment of CISC+ functional CD19-CAR-T cells. Together, CISC provides a robust platform to achieve both in vitro enrichment and in vivo engraftment and activation, features likely beneficial across multiple gene-edited T cell applications.


Subject(s)
CD4-Positive T-Lymphocytes , Interleukin-2 , Mice , Animals , CD4-Positive T-Lymphocytes/metabolism , Interleukin-2/genetics , Interleukin-2/pharmacology , Interleukin-2/metabolism , T-Lymphocytes, Regulatory/metabolism , Sirolimus/pharmacology , Receptors, Interleukin-2/metabolism
3.
Sci Transl Med ; 14(665): eabn1716, 2022 10 05.
Article in English | MEDLINE | ID: mdl-36197963

ABSTRACT

Adoptive transfer of regulatory T cells (Tregs) is therapeutic in type 1 diabetes (T1D) mouse models. Tregs that are specific for pancreatic islets are more potent than polyclonal Tregs in preventing disease. However, the frequency of antigen-specific natural Tregs is extremely low, and ex vivo expansion may destabilize Tregs, leading to an effector phenotype. Here, we generated durable, antigen-specific engineered Tregs (EngTregs) from primary human CD4+ T cells by combining FOXP3 homology-directed repair editing and lentiviral T cell receptor (TCR) delivery. Using TCRs derived from clonally expanded CD4+ T cells isolated from patients with T1D, we generated islet-specific EngTregs that suppressed effector T cell (Teff) proliferation and cytokine production. EngTregs suppressed Teffs recognizing the same islet antigen in addition to bystander Teffs recognizing other islet antigens through production of soluble mediators and both direct and indirect mechanisms. Adoptively transferred murine islet-specific EngTregs homed to the pancreas and blocked diabetes triggered by islet-specific Teffs or diabetogenic polyclonal Teffs in recipient mice. These data demonstrate the potential of antigen-specific EngTregs as a targeted therapy for preventing T1D.


Subject(s)
Diabetes Mellitus, Type 1 , Islets of Langerhans , Animals , Cytokines , Diabetes Mellitus, Type 1/genetics , Forkhead Transcription Factors , Humans , Mice , Receptors, Antigen, T-Cell , T-Lymphocytes, Regulatory
4.
Mol Ther Methods Clin Dev ; 20: 635-651, 2021 Mar 12.
Article in English | MEDLINE | ID: mdl-33718514

ABSTRACT

X-linked agammaglobulinemia (XLA) is an immune disorder caused by mutations in Bruton's tyrosine kinase (BTK). BTK is expressed in B and myeloid cells, and its deficiency results in a lack of mature B cells and protective antibodies. We previously reported a lentivirus (LV) BTK replacement therapy that restored B cell development and function in Btk and Tec double knockout mice (a phenocopy of human XLA). In this study, with the goal of optimizing both the level and lineage specificity of BTK expression, we generated LV incorporating the proximal human BTK promoter. Hematopoietic stem cells from Btk -/- Tec -/- mice transduced with this vector rescued lineage-specific expression and restored B cell function in Btk -/- Tec -/- recipients. Next, we tested addition of candidate enhancers and/or ubiquitous chromatin opening elements (UCOEs), as well as codon optimization to improve BTK expression. An Eµ enhancer improved B cell rescue, but increased immunoglobulin G (IgG) autoantibodies. Addition of the UCOE avoided autoantibody generation while improving B cell development and function and reducing vector silencing. An optimized vector containing a truncated UCOE upstream of the BTK promoter and codon-optimized BTK cDNA resulted in stable, lineage-regulated BTK expression that mirrored endogenous BTK, making it a strong candidate for XLA therapy.

5.
Sci Transl Med ; 12(546)2020 06 03.
Article in English | MEDLINE | ID: mdl-32493794

ABSTRACT

Thymic regulatory T cells (tTregs) are potent inhibitors of autoreactive immune responses, and loss of tTreg function results in fatal autoimmune disease. Defects in tTreg number or function are also implicated in multiple autoimmune diseases, leading to growing interest in use of Treg as cell therapies to establish immune tolerance. Because tTregs are present at low numbers in circulating blood and may be challenging to purify and expand and also inherently defective in some subjects, we designed an alternative strategy to create autologous Treg-like cells from bulk CD4+ T cells. We used homology-directed repair (HDR)-based gene editing to enforce expression of FOXP3, the master transcription factor for tTreg Targeted insertion of a robust enhancer/promoter proximal to the first coding exon bypassed epigenetic silencing, permitting stable and robust expression of endogenous FOXP3. HDR-edited T cells, edTregs, manifested a transcriptional program leading to sustained expression of canonical markers and suppressive activity of tTreg Both human and murine edTregs mediated immunosuppression in vivo in models of inflammatory disease. Further, this engineering strategy permitted generation of antigen-specific edTreg with robust in vitro and in vivo functional activity. Last, edTreg could be enriched and expanded at scale using clinically relevant methods. Together, these findings suggest that edTreg production may permit broad future clinical application.


Subject(s)
Forkhead Transcription Factors , Gene Editing , Animals , Forkhead Transcription Factors/genetics , Humans , Immune Tolerance , Mice , Phenotype , T-Lymphocytes, Regulatory
6.
J Exp Med ; 215(9): 2445-2461, 2018 09 03.
Article in English | MEDLINE | ID: mdl-30127060

ABSTRACT

Activating mutations in the adapter protein CARD11 associated with diffuse large B cell lymphomas (DLBCLs) are predicted to arise during germinal center (GC) responses, leading to inappropriate activation of NF-κB signaling. Here, we modeled the B cell-intrinsic impact of the L251P activating mutation in CARD11 (aCARD11) on the GC response. Global B cell aCARD11 expression led to a modest increase in splenic B cells and a severe reduction in B1 B cell numbers, respectively. Following T cell-dependent immunization, aCARD11 cells exhibited increased rates of GC formation, resolution, and differentiation. Restriction of aCARD11 to GC B cells similarly altered the GC response and B cell differentiation. In this model, aCARD11 promoted dark zone skewing along with increased cycling, AID levels, and class switch recombination. Furthermore, aCard11 GC B cells displayed increased biomass and mTORC1 signaling, suggesting a novel strategy for targeting aCARD11-driven DLBCL. While aCARD11 potently impacts GC responses, the rapid GC contraction suggests it requires collaboration with events that limit terminal differentiation to promote lymphoma.


Subject(s)
B-Lymphocytes/immunology , CARD Signaling Adaptor Proteins/immunology , Cell Differentiation/immunology , Germinal Center/immunology , Lymphoma, Large B-Cell, Diffuse/immunology , Mechanistic Target of Rapamycin Complex 1/immunology , Models, Immunological , Neoplasm Proteins/immunology , Signal Transduction/immunology , Animals , B-Lymphocytes/pathology , CARD Signaling Adaptor Proteins/genetics , Cell Differentiation/genetics , Germinal Center/pathology , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/pathology , Mechanistic Target of Rapamycin Complex 1/genetics , Mice , Mice, Transgenic , Neoplasm Proteins/genetics , Signal Transduction/genetics
7.
Mol Ther Methods Clin Dev ; 4: 1-16, 2017 Mar 17.
Article in English | MEDLINE | ID: mdl-28344987

ABSTRACT

Wiskott-Aldrich syndrome (WAS) is a life-threatening immunodeficiency caused by mutations within the WAS gene. Viral gene therapy to restore WAS protein (WASp) expression in hematopoietic cells of patients with WAS has the potential to improve outcomes relative to the current standard of care, allogeneic bone marrow transplantation. However, the development of viral vectors that are both safe and effective has been problematic. While use of viral transcriptional promoters may increase the risk of insertional mutagenesis, cellular promoters may not achieve WASp expression levels necessary for optimal therapeutic effect. Here we evaluate a self-inactivating (SIN) lentiviral vector combining a chromatin insulator upstream of a viral MND (MPSV LTR, NCR deleted, dl587 PBS) promoter driving WASp expression. Used as a gene therapeutic in Was-/- mice, this vector resulted in stable WASp+ cells in all hematopoietic lineages and rescue of T and B cell defects with a low number of viral integrations per cell, without evidence of insertional mutagenesis in serial bone marrow transplants. In a gene transfer experiment in non-human primates, the insulated MND promoter (driving GFP expression) demonstrated long-term polyclonal engraftment of GFP+ cells. These observations demonstrate that the insulated MND promoter safely and efficiently reconstitutes clinically effective WASp expression and should be considered for future WAS therapy.

8.
Mol Ther Methods Clin Dev ; 4: 192-203, 2017 Mar 17.
Article in English | MEDLINE | ID: mdl-28345004

ABSTRACT

Gene editing by homology-directed recombination (HDR) can be used to couple delivery of a therapeutic gene cassette with targeted genomic modifications to generate engineered human T cells with clinically useful profiles. Here, we explore the functionality of therapeutic cassettes delivered by these means and test the flexibility of this approach to clinically relevant alleles. Because CCR5-negative T cells are resistant to HIV-1 infection, CCR5-negative anti-CD19 chimeric antigen receptor (CAR) T cells could be used to treat patients with HIV-associated B cell malignancies. We show that targeted delivery of an anti-CD19 CAR cassette to the CCR5 locus using a recombinant AAV homology template and an engineered megaTAL nuclease results in T cells that are functionally equivalent, in both in vitro and in vivo tumor models, to CAR T cells generated by random integration using lentiviral delivery. With the goal of developing off-the-shelf CAR T cell therapies, we next targeted CARs to the T cell receptor alpha constant (TRAC) locus by HDR, producing TCR-negative anti-CD19 CAR and anti-B cell maturation antigen (BCMA) CAR T cells. These novel cell products exhibited in vitro cytolytic activity against both tumor cell lines and primary cell targets. Our combined results indicate that high-efficiency HDR delivery of therapeutic genes may provide a flexible and robust method that can extend the clinical utility of cell therapeutics.

9.
Mol Ther ; 25(3): 570-579, 2017 03 01.
Article in English | MEDLINE | ID: mdl-28143740

ABSTRACT

The treatment or cure of HIV infection by cell and gene therapy has been a goal for decades. Recent advances in both gene editing and chimeric antigen receptor (CAR) technology have created new therapeutic possibilities for a variety of diseases. Broadly neutralizing monoclonal antibodies (bNAbs) with specificity for the HIV envelope glycoprotein provide a promising means of targeting HIV-infected cells. Here we show that primary human T cells engineered to express anti-HIV CARs based on bNAbs (HIVCAR) show specific activation and killing of HIV-infected versus uninfected cells in the absence of HIV replication. We also show that homology-directed recombination of the HIVCAR gene expression cassette into the CCR5 locus enhances suppression of replicating virus compared with HIVCAR expression alone. This work demonstrates that HIV immunotherapy utilizing potent bNAb-based single-chain variable fragments fused to second-generation CAR signaling domains, delivered directly into the CCR5 locus of T cells by homology-directed gene editing, is feasible and effective. This strategy has the potential to target HIV-infected cells in HIV-infected individuals, which might help in the effort to cure HIV.


Subject(s)
HIV Antibodies/immunology , HIV Infections/immunology , HIV Infections/therapy , HIV-1/immunology , Lymphocyte Subsets/immunology , Lymphocyte Subsets/metabolism , Receptors, Antigen, T-Cell/metabolism , Recombinant Fusion Proteins , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/metabolism , Cytotoxicity, Immunologic , Epitopes/immunology , Gene Order , Genetic Engineering , Genetic Vectors/genetics , HIV Antibodies/genetics , HIV Antibodies/metabolism , HIV Envelope Protein gp120/immunology , HIV Infections/genetics , Humans , Immunotherapy , Lymphocyte Activation/immunology , Receptors, Antigen, T-Cell/genetics , Receptors, CCR5/genetics , Receptors, CCR5/metabolism , Single-Chain Antibodies , Virus Replication
10.
Mol Ther Nucleic Acids ; 5(8): e352, 2016 Aug 23.
Article in English | MEDLINE | ID: mdl-27741222

ABSTRACT

A naturally occurring 32-base pair deletion of the HIV-1 co-receptor CCR5 has demonstrated protection against HIV infection of human CD4+ T cells. Recent genetic engineering approaches using engineered nucleases to disrupt the gene and mimic this mutation show promise for HIV therapy. We developed a megaTAL nuclease targeting the third extracellular loop of CCR5 that we delivered to primary human T cells by mRNA transfection. The CCR5 megaTAL nuclease established resistance to HIV in cell lines and disrupted the expression of CCR5 on primary human CD4+ T cells with a high efficiency, achieving up to 80% modification of the locus in primary cells as measured by molecular analysis. Gene-modified cells engrafted at levels equivalent to unmodified cells when transplanted into immunodeficient mice. Furthermore, genetically modified CD4+ cells were preferentially expanded during HIV-1 infection in vivo in an immunodeficient mouse model. Our results demonstrate the feasibility of targeting CCR5 in primary T cells using an engineered megaTAL nuclease, and the potential to use gene-modified cells to reconstitute a patient's immune system and provide protection from HIV infection.

11.
Blood ; 127(21): 2513-22, 2016 05 26.
Article in English | MEDLINE | ID: mdl-26903548

ABSTRACT

Loss of CD40 ligand (CD40L) expression or function results in X-linked hyper-immunoglobulin (Ig)M syndrome (X-HIGM), characterized by recurrent infections due to impaired immunoglobulin class-switching and somatic hypermutation. Previous attempts using retroviral gene transfer to correct murine CD40L expression restored immune function; however, treated mice developed lymphoproliferative disease, likely due to viral-promoter-dependent constitutive CD40L expression. These observations highlight the importance of preserving endogenous gene regulation in order to safely correct this disorder. Here, we report efficient, on-target, homology-directed repair (HDR) editing of the CD40LG locus in primary human T cells using a combination of a transcription activator-like effector nuclease-induced double-strand break and a donor template delivered by recombinant adeno-associated virus. HDR-mediated insertion of a coding sequence (green fluorescent protein or CD40L) upstream of the translation start site within exon 1 allowed transgene expression to be regulated by endogenous CD40LG promoter/enhancer elements. Additionally, inclusion of the CD40LG 3'-untranslated region in the transgene preserved posttranscriptional regulation. Expression kinetics of the transgene paralleled that of endogenous CD40L in unedited T cells, both at rest and in response to T-cell stimulation. The use of this method to edit X-HIGM patient T cells restored normal expression of CD40L and CD40-murine IgG Fc fusion protein (CD40-muIg) binding, and rescued IgG class switching of naive B cells in vitro. These results demonstrate the feasibility of engineered nuclease-directed gene repair to restore endogenously regulated CD40L, and the potential for its use in T-cell therapy for X-HIGM syndrome.


Subject(s)
B-Lymphocytes/immunology , CD40 Ligand , Gene Editing/methods , Gene Expression Regulation/immunology , Hyper-IgM Immunodeficiency Syndrome, Type 1 , T-Lymphocytes/immunology , Targeted Gene Repair/methods , 3' Untranslated Regions/immunology , Animals , CD40 Ligand/genetics , CD40 Ligand/immunology , Enhancer Elements, Genetic/immunology , Female , Humans , Hyper-IgM Immunodeficiency Syndrome, Type 1/genetics , Hyper-IgM Immunodeficiency Syndrome, Type 1/immunology , Hyper-IgM Immunodeficiency Syndrome, Type 1/therapy , Immunoglobulin Class Switching/genetics , Immunoglobulin Class Switching/immunology , Male , Mice , Mice, Inbred NOD , Mice, SCID , Somatic Hypermutation, Immunoglobulin/genetics , Somatic Hypermutation, Immunoglobulin/immunology
12.
Sci Transl Med ; 7(307): 307ra156, 2015 Sep 30.
Article in English | MEDLINE | ID: mdl-26424571

ABSTRACT

Genetic mutations or engineered nucleases that disrupt the HIV co-receptor CCR5 block HIV infection of CD4(+) T cells. These findings have motivated the engineering of CCR5-specific nucleases for application as HIV therapies. The efficacy of this approach relies on efficient biallelic disruption of CCR5, and the ability to efficiently target sequences that confer HIV resistance to the CCR5 locus has the potential to further improve clinical outcomes. We used RNA-based nuclease expression paired with adeno-associated virus (AAV)-mediated delivery of a CCR5-targeting donor template to achieve highly efficient targeted recombination in primary human T cells. This method consistently achieved 8 to 60% rates of homology-directed recombination into the CCR5 locus in T cells, with over 80% of cells modified with an MND-GFP expression cassette exhibiting biallelic modification. MND-GFP-modified T cells maintained a diverse repertoire and engrafted in immune-deficient mice as efficiently as unmodified cells. Using this method, we integrated sequences coding chimeric antigen receptors (CARs) into the CCR5 locus, and the resulting targeted CAR T cells exhibited antitumor or anti-HIV activity. Alternatively, we introduced the C46 HIV fusion inhibitor, generating T cell populations with high rates of biallelic CCR5 disruption paired with potential protection from HIV with CXCR4 co-receptor tropism. Finally, this protocol was applied to adult human mobilized CD34(+) cells, resulting in 15 to 20% homologous gene targeting. Our results demonstrate that high-efficiency targeted integration is feasible in primary human hematopoietic cells and highlight the potential of gene editing to engineer T cell products with myriad functional properties.


Subject(s)
Deoxyribonucleases/metabolism , Dependovirus/metabolism , Hematopoietic Stem Cells/metabolism , Receptors, CCR5/metabolism , Adult , Antigens, CD34/metabolism , CD3 Complex/metabolism , Cells, Cultured , DNA Repair , Genetic Loci , Genetic Therapy , Green Fluorescent Proteins/metabolism , Humans , RNA Editing/genetics , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes/metabolism
13.
J Oncol Pract ; 10(5): e293-8, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24963136

ABSTRACT

INTRODUCTION: Although survivorship care recommendations exist, there is limited evidence about current practices and patient preferences. METHODS: A cross-sectional survey was completed by survivors of lymphoma, head and neck, and gastrointestinal cancers at an academic cancer center. The survey was designed to capture patients' reports of receipt of survivorship care planning and their attitudes, preferences, and perceived needs regarding content and timing of cancer survivorship care information. Elements of survivorship care were based on the Institute of Medicine recommendations, literature review, and clinical experience. RESULTS: Eighty-five survivors completed the survey (response rate, 81%). More than 75% reported receiving a follow-up plan or appointment schedule, a monitoring plan for scans and blood tests, information about short- and long-term adverse effects, and a detailed treatment summary. These elements were reported as desired by more than 90% of responders. Approximately 40% of these elements were only verbally provided. Although more than 70% described not receiving information about employment, smoking cessation, sexual health, genetic counseling, fertility, or financial resources, these elements were not reported as desired. However, "strategies to cope with the fear of recurrence" was most often omitted, yet desired by most respondents. Survivors' preferences regarding optimal timing for information varied depending on the element. CONCLUSIONS: Our study suggests that cancer survivorship care planning is heterogeneous and may not need to be comprehensive, but rather tailored to individual survivors' needs. Providers must assess patient needs early and continue to revisit them during the cancer care continuum.


Subject(s)
Gastrointestinal Neoplasms/therapy , Head and Neck Neoplasms/therapy , Lymphoma/therapy , Neoplasms/therapy , Survivors , Adult , Aged , Attitude , Continuity of Patient Care , Cross-Sectional Studies , Female , Follow-Up Studies , Gastrointestinal Neoplasms/psychology , Head and Neck Neoplasms/psychology , Humans , Internet , Lymphoma/psychology , Male , Medical Oncology/methods , Medical Oncology/trends , Middle Aged , Neoplasms/psychology , Patient Care Planning , Patient Preference , Surveys and Questionnaires , Treatment Outcome , Young Adult
14.
J Clin Oncol ; 32(6): 496-503, 2014 Feb 20.
Article in English | MEDLINE | ID: mdl-24419123

ABSTRACT

PURPOSE: To identify and characterize potentially avoidable hospitalizations in patients with GI malignancies. PATIENTS AND METHODS: We compiled a retrospective series of sequential hospital admissions in patients with GI cancer. Patients were admitted to an inpatient medical oncology or palliative care service between December 2011 and July 2012. Practicing oncology clinicians used a consensus-driven medical record review process to categorize each hospitalization as "potentially avoidable" or "not avoidable." Patient demographic and clinical data were abstracted, and quantitative and qualitative analyses were performed to identify patient characteristics and outcomes associated with potentially avoidable hospitalizations. RESULTS: We evaluated 201 hospitalizations in 154 unique patients. The median age was 62 years, and colorectal cancer was the most common diagnosis (32%). The majority of hospitalized patients had metastatic cancer (81%). In all, 53% of hospitalizations were attributable to cancer symptoms, and 28% were attributable to complications of cancer treatment. Medical oncologists identified 39 hospitalizations (19%) as potentially avoidable. Hospitalizations were more likely to be categorized as potentially avoidable for patients with the following characteristics: age ≥ 70 years (odds ratio [OR], 2.63; 95% CI, 1.15 to 6.02), receipt of an oncologist's advice to consider hospice (OR, 6.09; 95% CI, 2.54 to 14.58), or receipt of three or more lines of chemotherapy (OR, 2.68; 95% CI, 1.01 to 7.08). Ninety-day mortality was higher after avoidable hospitalizations compared with hospitalizations that were not avoidable (OR, 6.4; 95% CI, 1.8 to 22.3). CONCLUSION: Potentially avoidable hospitalizations are common in patients with advanced GI cancer. The majority of potentially avoidable hospitalizations occurred in patients with advanced treatment-refractory cancers near the end of life.


Subject(s)
Gastrointestinal Neoplasms/diagnosis , Gastrointestinal Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Electronic Health Records , Female , Hospitalization , Humans , Male , Middle Aged , Palliative Care/methods , Randomized Controlled Trials as Topic , Retrospective Studies , Young Adult
15.
Mol Cell Biol ; 33(6): 1149-63, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23297344

ABSTRACT

Antigen receptors activate pathways that control cell survival, proliferation, and differentiation. Two important targets of antigen receptors, NF-κB and Jun N-terminal kinase (JNK), are activated downstream of CARMA1, a scaffolding protein that nucleates a complex including BCL10, MALT1, and other IκB kinase (IKK)-signalosome components. Somatic mutations that constitutively activate CARMA1 occur frequently in diffuse large B cell lymphoma (DLBCL) and mediate essential survival signals. Mechanisms that downregulate this pathway might thus yield important therapeutic targets. Stimulation of antigen receptors induces not only BCL10 activation but also its degradation downstream of CARMA1, thereby ultimately limiting signals to its downstream targets. Here, using lymphocyte cell models, we identify a kinase-independent requirement for TAK1 and its adaptor, TAB1, in antigen receptor-induced BCL10 degradation. We show that TAK1 acts as an adaptor for E3 ubiquitin ligases that target BCL10 for degradation. Functionally, TAK1 overexpression restrains CARMA1-dependent activation of NF-κB by reducing BCL10 levels. TAK1 also promotes counterselection of NF-κB-addicted DLBCL lines by a dual mechanism involving kinase-independent degradation of BCL10 and kinase-dependent activation of JNK. Thus, by directly promoting BCL10 degradation, TAK1 counterbalances NF-κB and JNK signals essential for the activation and survival of lymphocytes and CARMA1-addicted lymphoma types.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , CARD Signaling Adaptor Proteins/metabolism , Endosomal Sorting Complexes Required for Transport/metabolism , MAP Kinase Kinase Kinases/metabolism , NF-kappa B/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , B-Lymphocytes/metabolism , Cell Line , Chickens , HEK293 Cells , Humans , MAP Kinase Kinase 4/metabolism , Mice , Mice, Inbred C57BL , Protein Kinase C/metabolism , Protein Kinase C beta , Proteolysis , Receptors, Antigen/metabolism , Signal Transduction , T-Lymphocytes/metabolism , Ubiquitination
16.
Mol Cell Biol ; 30(4): 922-34, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20008554

ABSTRACT

The adaptor protein CARMA1 is required for antigen receptor-triggered activation of IKK and JNK in lymphocytes. Once activated, the events that subsequently turn off the CARMA1 signalosome are unknown. In this study, we found that antigen receptor-activated CARMA1 underwent lysine 48 (K48) polyubiquitination and proteasome-dependent degradation. The MAGUK region of CARMA1 was an essential player in this event; the SH3 and GUK domains contained the main ubiquitin acceptor sites, and deletion of a Hook domain (an important structure for maintaining inactive MAGUK proteins) between SH3 and GUK was sufficient to induce constitutive ubiquitination of CARMA1. A similar deletion promoted the ubiquitination of PSD-95 and Dlgh1, suggesting that a conserved mechanism may control the turnover of other MAGUK family protein complexes. Functionally, we demonstrated that elimination of MAGUK ubiquitination sites in CARMA1 resulted in elevated basal and inducible NF-kappaB and JNK activation as a result of defective K48 ubiquitination and increased persistence of this ubiquitination-deficient CARMA1 protein in activated lymphocytes. The coordination of degradation with the full activation of the CARMA1 molecule likely provides an intrinsic feedback control mechanism to balance lymphocyte activation upon antigenic stimulation.


Subject(s)
Avian Proteins/metabolism , CARD Signaling Adaptor Proteins/metabolism , Lymphocytes/metabolism , NF-kappa B/metabolism , Ubiquitination , Amino Acid Sequence , Animals , Avian Proteins/deficiency , CARD Signaling Adaptor Proteins/chemistry , CARD Signaling Adaptor Proteins/deficiency , CARD Signaling Adaptor Proteins/genetics , Cells, Cultured , Chickens , Humans , Mice , Molecular Sequence Data , Mutation , Proteasome Endopeptidase Complex/metabolism , Protein Interaction Domains and Motifs , Protein Kinase C/deficiency , Protein Kinase C/metabolism , Protein Kinase C beta , Sequence Alignment
17.
J Immunol ; 183(11): 7362-70, 2009 Dec 01.
Article in English | MEDLINE | ID: mdl-19917688

ABSTRACT

Phosphorylation of CARMA1 is a crucial event initiating the assembly of IkappaB kinase and JNK signaling complexes downstream of activated Ag receptors. We previously mapped three protein kinase C (PKC) target sites in murine CARMA1 in vitro, and demonstrated that mutation of two of these serines (S564 and S657) resulted in reduced NF-kappaB activation, whereas mutation of the third serine (S649) had no clear effect. In this study, we report that when low concentrations of Ag receptor activators are used, loss of S649 (by mutation to alanine) promotes enhanced IkappaB kinase and JNK activation in both B and T cell lines. Reconstitution of CARMA1(-/-) DT40 B cells with CARMA1 S649A leads to increased cell death and reduced cell growth in comparison to wild-type CARMA1, likely a result of enhanced JNK activation. To directly determine whether S649 is modified in vivo, we generated phospho-specific Abs recognizing phospho-S649, and phospho-S657 as a positive control. Although phospho-S657 peaked and declined rapidly after Ag receptor stimulation, phospho-S649 occurred later and was maintained for a significantly longer period poststimulation in both B and T cells. Interestingly, phospho-S657 was completely abolished in PKCbeta-deficient B cells, whereas delayed phosphorylation at S649 was partially intact and depended, in part, upon novel PKC activity. Thus, distinct PKC-mediated CARMA1 phosphorylation events exert opposing effects on the activation status of CARMA1. We propose that early phosphorylation events at S657 and S564 promote the initial assembly of the CARMA1 signalosome, whereas later phosphorylation at S649 triggers CARMA1 down-regulation.


Subject(s)
B-Lymphocytes/enzymology , CARD Signaling Adaptor Proteins/metabolism , Guanylate Cyclase/metabolism , Protein Kinase C/metabolism , Signal Transduction/immunology , T-Lymphocytes/enzymology , Animals , B-Lymphocytes/immunology , Blotting, Western , CARD Signaling Adaptor Proteins/immunology , Cell Line , Chickens , Down-Regulation , Enzyme Activation , Guanylate Cyclase/immunology , Humans , I-kappa B Kinase/immunology , I-kappa B Kinase/metabolism , Immunoprecipitation , MAP Kinase Kinase 4/immunology , MAP Kinase Kinase 4/metabolism , Mice , Phosphorylation , Protein Kinase C/immunology , Serine/metabolism , T-Lymphocytes/immunology
18.
Sci Signal ; 2(72): ra25, 2009 May 26.
Article in English | MEDLINE | ID: mdl-19471023

ABSTRACT

Wnts are secreted ligands that activate several receptor-mediated signal transduction cascades. Homeostatic Wnt signaling through beta-catenin is required in adults, because either elevation or attenuation of beta-catenin function has been linked to diverse diseases. To contribute to the identification of both protein and pharmacological regulators of this pathway, we describe a combinatorial screen that merged data from a high-throughput screen of known bioactive compounds with an independent focused small interfering RNA screen. Each screen independently revealed Bruton's tyrosine kinase (BTK) as an inhibitor of Wnt-beta-catenin signaling. Loss of BTK function in human colorectal cancer cells, human B cells, zebrafish embryos, and cells derived from X-linked agammaglobulinemia patients with a mutant BTK gene resulted in elevated Wnt-beta-catenin signaling, confirming that BTK acts as a negative regulator of this pathway. From affinity purification-mass spectrometry and biochemical binding studies, we found that BTK directly interacts with a nuclear component of Wnt-beta-catenin signaling, CDC73. Further, we show that BTK increased the abundance of CDC73 in the absence of stimulation and that CDC73 acted as a repressor of beta-catenin-mediated transcription in human colorectal cancer cells and B cells.


Subject(s)
Protein-Tyrosine Kinases/metabolism , Signal Transduction , Wnt Proteins/metabolism , beta Catenin/metabolism , Agammaglobulinaemia Tyrosine Kinase , Animals , Cell Line , Chromatography, Affinity , Humans , Mass Spectrometry , Protein-Tyrosine Kinases/isolation & purification
19.
Jt Comm J Qual Patient Saf ; 33(2): 83-94, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17370919

ABSTRACT

BACKGROUND: Although patients suffer the effects of medical errors and iatrogenic injuries, little is known about their ability to recognize these events in ambulatory specialty care. METHODS: At a Boston cancer center in 2004, 193 adult oncology patients treated on a chemotherapy infusion unit were interviewed by four patient safety liaisons--volunteers recruited from the organization's Adult Patient and Family Advisory Council. RESULTS: Among 193 patients, 83 reported 121 incidents. Investigators classified 2 (1%) adverse events, 4 (2%) close calls, 14 (7%) errors without risk of harm, and 101 (52%) service quality incidents. Respondents reported high staff compliance with safe practices such as identity checking (95%). Examining the most serious described by each of 42 (22%) respondents who reported a recent unsafe experience, investigators classified only one adverse event, 3 close calls, 9 harmless errors, and 27 service quality incidents. DISCUSSION: Patients' perception of unsafe care was surprising, given the same patients' recognition of consistent application of safe practices, such as the use of two forms of identification before performing tests and administering treatments. Many ambulatory oncology patients also reported poor service quality. The relationship between patient perception of safe care, medical injury, and service quality merits further study.


Subject(s)
Medical Errors/classification , Neoplasms , Oncology Service, Hospital/standards , Outpatient Clinics, Hospital/standards , Outpatients/psychology , Patient Satisfaction , Quality Indicators, Health Care , Safety/standards , Adult , Boston , Cancer Care Facilities , Family/psychology , Health Care Surveys , Humans , Interviews as Topic , Medical Errors/psychology , Neoplasms/diagnosis , Neoplasms/psychology , Neoplasms/therapy , Outpatients/education , Patient Education as Topic , Perception , Prospective Studies
20.
Nat Rev Immunol ; 6(11): 799-812, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17063183

ABSTRACT

The recognition of antigen by B- or T-cell receptors initiates an intracellular signalling cascade that results in the nuclear translocation and activation of the transcription factor nuclear factor-kappaB (NF-kappaB). NF-kappaB is an important regulator of lymphocyte development and function, and its dysregulation is associated with many immune disorders. Defining the mechanisms that transmit signals from the antigen receptor to NF-kappaB is therefore an important goal for immunologists. In this Review, we merge information gleaned from research of the innate immune system with what we know about antigen-receptor signals in the adaptive immune system, to propose a cohesive model of how antigen receptors activate NF-kappaB.


Subject(s)
Apoptosis Regulatory Proteins/immunology , Guanylate Cyclase/immunology , Immunity, Innate/immunology , Lymphocytes/immunology , Signal Transduction/immunology , Animals , Apoptosis Regulatory Proteins/metabolism , Guanylate Cyclase/metabolism , Humans , Lymphocytes/metabolism
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