[Show abstract][Hide abstract]ABSTRACT: CTLA-4 is a critical inhibitory "checkpoint" molecule of immune activation. Several recent reports have described patients with immune dysregulation and lymphoproliferative disease resulting from two different genetic diseases that directly or indirectly cause CTLA-4 deficiency. Numerous articles have also been published describing CTLA-4 blockade in cancer immunotherapy and its side effects, which are ultimately the consequence of treatment-induced CTLA-4 deficiency. Here, we review these two diseases and CTLA-4 blockade therapy, emphasizing the crucial role of CTLA-4 in immune checkpoint regulation.
[Show abstract][Hide abstract]ABSTRACT: Background Activated phosphoinositide 3-kinase δ syndrome (APDS) 2 (p110δ-activating mutations causing senescent T cells, lymphadenopathy, and immunodeficiency [PASLI]–R1), a recently described primary immunodeficiency, results from autosomal dominant mutations in PIK3R1, the gene encoding the regulatory subunit (p85α, p55α, and p50α) of class IA phosphoinositide 3-kinases. Objectives We sought to review the clinical, immunologic, and histopathologic phenotypes of APDS2 in a genetically defined international patient cohort. Methods The medical and biological records of 36 patients with genetically diagnosed APDS2 were collected and reviewed. Results Mutations within splice acceptor and donor sites of exon 11 of the PIK3R1 gene lead to APDS2. Recurrent upper respiratory tract infections (100%), pneumonitis (71%), and chronic lymphoproliferation (89%, including adenopathy [75%], splenomegaly [43%], and upper respiratory tract lymphoid hyperplasia [48%]) were the most common features. Growth retardation was frequently noticed (45%). Other complications were mild neurodevelopmental delay (31%); malignant diseases (28%), most of them being B-cell lymphomas; autoimmunity (17%); bronchiectasis (18%); and chronic diarrhea (24%). Decreased serum IgA and IgG levels (87%), increased IgM levels (58%), B-cell lymphopenia (88%) associated with an increased frequency of transitional B cells (93%), and decreased numbers of naive CD4 and naive CD8 cells but increased numbers of CD8 effector/memory T cells were predominant immunologic features. The majority of patients (89%) received immunoglobulin replacement; 3 patients were treated with rituximab, and 6 were treated with rapamycin initiated after diagnosis of APDS2. Five patients died from APDS2-related complications. Conclusion APDS2 is a combined immunodeficiency with a variable clinical phenotype. Complications are frequent, such as severe bacterial and viral infections, lymphoproliferation, and lymphoma similar to APDS1/PASLI-CD. Immunoglobulin replacement therapy, rapamycin, and, likely in the near future, selective phosphoinositide 3-kinase δ inhibitors are possible treatment options.
[Show abstract][Hide abstract]ABSTRACT: This review provides a synopsis for genetic counselors of the major concepts of lymphoma predisposition: genomic instability, immune deficiency, inappropriate lymphoproliferation, and chronic antigen stimulation. We discuss syndromes typifying each of these mechanisms. Importantly, our review of the genetic counseling literature reveals sparse discussion of genetically-based immune-mediated lymphoma predisposition, which we address in depth here. We aim to increase awareness among genetic counselors and colleagues in oncology about familial susceptibility and facilitate critical thinking about lymphoma risk assessment. Clinical application of this knowledge is aided by recommendations for collection of personal and family history to guide risk assessment and testing. Lastly, we include a special discussion of genetic counseling issues including perceptions of the context, nature, and magnitude of lymphoma risk, as well as coping with awareness of susceptibility to lymphoma.
Full-text available · Article · Jun 2016 · Journal of Genetic Counseling
[Show abstract][Hide abstract]ABSTRACT: Activated PI3-kinase delta syndrome 2 (APDS2/PASLI-R1), a recently described primary immunodeficiency, results from autosomal dominant mutations in PIK3R1, the gene encoding the regulatory subunit (p85α, p55α and p50α) of class IA PI3-kinases.
Article · Apr 2016 · Journal of Allergy and Clinical Immunology
[Show abstract][Hide abstract]ABSTRACT: Purpose:
The clinical immunology literature is punctuated with research on psychosocial dimensions of illness. Studies investigating the lived experiences and stated needs of patients with primary immune deficiencies and their families are essential to improving clinical management and determining the research questions that matter to patients and other stakeholders. Yet, to move the field forward, a systematic review of literature and proposed agenda is needed.
A systematic review was conducted via PubMed and Scopus to include original research on psychological, social, or behavioral aspects of primary immune deficiencies published between 1999 and 2015. A Title/Abstract keyword search was conducted, 317 candidate article abstracts were manually reviewed, and forward/backward reference searches were completed.
Twenty-nine studies met inclusion criteria. These illuminate the complex psychological, social, and emotional experiences of primary immune deficiency. Themes included the potential for negative psychosocial impact from disease; adaptation over time; the multi-dimensional assessments of quality of life; familial impact; the important roles of hope, developing a sense of control, social support; and addressing anxiety/depression in our patients and their families. Methodological considerations and areas for improvement are discussed.
We propose the research agenda focus on study creativity and rigor, with improved engagement with existing literature and critical study design (e.g., methodology with adequate statistical power, careful variable selection, etc.). This review highlights opportunities to advance psychosocial research and bring a brighter future to clinicians, researchers, and families affected by primary immune deficiency.
Article · Feb 2016 · Journal of Clinical Immunology
[Show abstract][Hide abstract]ABSTRACT: Necroptosis as a molecular program, rather than simply incidental cell death, was established by elucidating the roles of receptor interacting protein (RIP) kinases 1 and 3, along with their downstream partner, mixed lineage kinase-like domain protein (MLKL). Previous studies suggested that phosphoglycerate mutase family member 5 (PGAM5), a mitochondrial protein that associates with RIP1/RIP3/MLKL complex, promotes necroptosis. We have generated mice deficient in the pgam5 gene and surprisingly found PGAM5-deficiency exacerbated rather than reduced necroptosis in response to multiple in vitro and in vivo necroptotic stimuli, including ischemic reperfusion injury (I/R) in the heart and brain. Electron microscopy, biochemical, and confocal analysis revealed that PGAM5 is indispensable for the process of PINK1 dependent mitophagy which antagonizes necroptosis. The loss of PGAM5/PINK1 mediated mitophagy causes the accumulation of abnormal mitochondria, leading to the overproduction of reactive oxygen species (ROS) that worsen necroptosis. Our results revise the former proposal that PGAM5 acts downstream of RIP1/RIP3 to mediate necroptosis. Instead, PGAM5 protects cells from necroptosis by independently promoting mitophagy. PGAM5 promotion of mitophagy may represent a therapeutic target for stroke, myocardial infarction and other diseases caused by oxidative damage and necroptosis.
Full-text available · Article · Jan 2016 · PLoS ONE
[Show abstract][Hide abstract]ABSTRACT: LDH cytotoxicity assay for the TCZ induced necroptosis in Pink1 WT and KO MEFs.
Pink1 WT and KO MEFs (50,000 cells/well) were plated in 24-well plate. 12 hours later, cells were treated with TNF-α, z-VAD and Cycloheximide as mentioned in the manuscript. LDH cytotoxicity was measured by using the Pierce LDH cytotoxity Assay Kit.
[Show abstract][Hide abstract]ABSTRACT: Re-introduced PINK1 in Pink1 KO MEFs protect cells from necroptosis.
Immortalized Pink1 KO MEFs were transduced with lentivirus expressing Wide type PINK1 protein, or control vector. Transduced KO MEFs and Pink1 WT MEFs were then treated with TNF-α, z-VAD as well as CHX as mentioned in the manuscript (Necroptosis inhibitor Necrostain 1 (Nec1) was also involved as an inhibitor for necroptosis). Finally, cell viability was evaluated by MTT assay.
[Show abstract][Hide abstract]ABSTRACT: GenomicDNAsequencing technologies have been one of the great advances of the 21st century, having decreased in cost by seven orders of magnitude and opening up new fields of investigation throughout research and clinical medicine. Genomics coupled with biochemical investigation has allowed the molecular definition of a growing number of new genetic diseases that reveal new concepts of immune regulation. Also, defining the genetic pathogenesis of these diseases has led to improved diagnosis, prognosis, genetic counseling, and, most importantly, new therapies. We highlight the investigational journey from patient phenotype to treatment using the newly defined XMEN disease, caused by the genetic loss of the MAGT1 magnesium transporter, as an example. This disease illustrates how genomics yields new fundamental immunoregulatory insights as well as how research genomics is integrated into clinical immunology. At the end, we discuss two other recently described diseases, PASLI (PI3K dysregulation) and CHAI/LATAIE (CTLA-4 deficiency), as additional examples of the journey from unknown immunological diseases to new precision medicine treatments using genomics. Expected final online publication date for the Annual Review of Immunology Volume 34 is May 20, 2016. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
[Show abstract][Hide abstract]ABSTRACT: Members of the miR-290 family are the most abundantly expressed microRNAs (miRNAs) in mouse embryonic stem cells (ESCs). They regulate aspects of differentiation, pluripotency, and proliferation of ESCs, but the molecular program that they control has not been fully delineated. In the absence of Dicer, ESCs fail to express mature miR-290 miRNAs and have selective aberrant overexpression of Hoxa, Hoxb, Hoxc, and Hoxd genes essential for body plan patterning during embryogenesis, but they do not undergo a full differentiation program. Introduction of mature miR-291 into DCR(-/-) ESCs restores Hox gene silencing. This was attributed to the unexpected regulation of Polycomb-mediated gene targeting by miR-291. We identified the methyltransferase Ash1l as a pivotal target of miR-291 mediating this effect. Collectively, our data shed light on the role of Dicer in ESC homeostasis by revealing a facet of molecular regulation by the miR-290 family.
Full-text available · Article · Nov 2015 · Stem Cell Reports
[Show abstract][Hide abstract]ABSTRACT: Background:
The most important complication in hemophilia A treatment is the development of inhibitory anti-Factor VIII (FVIII) antibodies in patients after FVIII therapy. Patients with severe hemophilia who express no endogenous FVIII, i.e. cross-reacting material (CRM), have the greatest incidence of inhibitor formation. However, current mouse models of severe hemophilia A produce low levels of truncated FVIII. The lack of a corresponding mouse model hampers the study of inhibitor formation in the complete absence of FVIII protein.
We aimed to generate and characterize a novel mouse model of severe hemophilia A (designated the F8(TKO) strain) lacking the complete coding sequence of F8 and any FVIII CRM.
Mice were created on a C57BL/6 background using Cre-Lox recombination and characterized using in vivo bleeding assays, measurement of FVIII activity by coagulation and chromogenic assays, and anti-FVIII antibody production using ELISA.
All F8 exonic coding regions were deleted from the genome and no F8 mRNA was detected in F8(TKO) mice. The bleeding phenotype of F8(TKO) mice was comparable to E16 mice by measurements of factor activity and tail snip assay. Similar levels of anti-FVIII antibody titers after recombinant FVIII injections were observed between F8(TKO) and E16 mice.
We describe a new C57BL/6 mouse model for severe hemophilia A patients lacking CRM. These mice can be directly bred to the many C57BL/6 strains of genetically engineered mice making it valuable for studying the impact of a wide variety of genes on FVIII inhibitor formation on a defined genetic background. This article is protected by copyright. All rights reserved.
Article · Nov 2015 · Journal of Thrombosis and Haemostasis
[Show abstract][Hide abstract]ABSTRACT: Common autoimmune diseases are relatively heterogeneous with both genetic and environmental factors influencing disease susceptibility and progression. As the populations in developed countries age, these chronic diseases will become an increasing burden in human suffering and health care costs. By contrast, rare immune diseases that are severe and develop early in childhood are frequently monogenic and fully penetrant, often with a Mendelian inheritance pattern. Although these may be incompatible with survival or cured by hematopoietic stem cell transplantation, we will argue that they constitute a rich source of genetic insights into immunological diseases. Here, we discuss five examples of well-studied Mendelian disease-causing genes and their known or predicted roles in conferring susceptibility to common, polygenic diseases of autoimmunity. Mendelian disease mutations, as experiments of nature, reveal human loci that are indispensable for immune regulation and, therefore, most promising as therapeutic targets.
Article · Oct 2015 · Current opinion in immunology
[Show abstract][Hide abstract]ABSTRACT: Advances in human genomics, when validated functionally, can lead to new insights into how the immune system works. Notably, previously unknown mechanisms revealed by genomics can lead to the development of precision medicine unanticipated on the basis of phenotype alone.