Research

Haploidentical Related Donor Hematopoietic Stem Cell Transplantation for DOCK8 Deficiency Using Post-Transplantation Cyclophosphamide.

March 16, 2017 By Manish Butte

Haploidentical Related Donor Hematopoietic Stem Cell Transplantation for DOCK8 Deficiency Using Post-Transplantation Cyclophosphamide.

Biol Blood Marrow Transplant. 2017 Mar 10;:

Authors: Shah NN, Freeman AF, Su H, Cole K, Parta M, Moutsopoulos NM, Baris S, Karakoc-Aydiner E, Hughes TE, Kong HH, Holland SM, Hickstein DD

Abstract
Dedicator-of-Cytokinesis-8 (DOCK8) deficiency, a primary immunodeficiency disease, can be reversed by allogeneic hematopoietic stem cell transplant (HSCT); however, there are few reports describing the use of alternative donor sources for HSCT in DOCK8 deficiency. We describe HSCT for patients with DOCK8 deficiency who lack a matched related or unrelated donor using bone marrow from haploidentical related donors and post-transplantation cyclophosphamide (PT/CY) for GVHD prophylaxis. Seven patients with DOCK8 deficiency (median age 20 years, range 7-25 years) received a haploidentical related donor HSCT. The conditioning regimen included 2 days of low-dose cyclophosphamide, 5 days of fludarabine, three days of busulfan, and 200 cGy TBI. Graft-versus host disease (GVHD) prophylaxis consisted of post-transplant cyclophosphamide (PT/CY) 50 mg/kg/day on days +3 and +4, and tacrolimus and mycophenolate mofetil starting at day +5. The median times to neutrophil and platelet engraftment were 15 and 19 days, respectively. All patients attained >90% donor engraftment by day +30. Four subjects developed acute GVHD (one with maximum grade 3). No patient developed chronic GVHD. With a median follow-up time of 20.6 months (range 9.5 – 31.7 months), 6 of 7 patients are alive and disease-free. Haploidentical related donor HSCT with PT/CY represents an effective therapeutic approach for patients with DOCK8 deficiency who lack a matched related or unrelated donor.

PMID: 28288951 [PubMed – as supplied by publisher]

Neurodegeneration in accelerated aging.

March 16, 2017 By Manish Butte

Neurodegeneration in accelerated aging.

Dan Med J. 2016 Nov;63(11):

Authors: Scheibye-Knudsen M

Abstract
The growing proportion of elderly people represents an increasing economic burden, not least because of age-associated diseases that pose a significant cost to the health service. Finding possible interventions to age-associated disorders therefore have wide ranging implications. A number of genetically defined accelerated aging diseases have been characterized that can aid in our understanding of aging. Interestingly, all these diseases are associated with defects in the maintenance of our genome. A subset of these disorders, Cockayne syndrome, Xeroderma pigmentosum group A and ataxia-telangiectasia, show neurological involvement reminiscent of what is seen in primary human mitochondrial diseases. Mitochondria are the power plants of the cells converting energy stored in oxygen, sugar, fat, and protein into ATP, the energetic currency of our body. Emerging evidence has linked this organelle to aging and finding mitochondrial dysfunction in accelerated aging disorders thereby strengthens the mitochondrial theory of aging. This theory states that an accumulation of damage to the mitochondria may underlie the process of aging. Indeed, it appears that some accelerated aging disorders that show neurodegeneration also have mitochondrial dysfunction. The mitochondrial alterations may be secondary to defects in nuclear DNA repair. Indeed, nuclear DNA damage may lead to increased energy consumption, alterations in mitochondrial ATP production and defects in mitochondrial recycling, a term called mitophagy. These changes may be caused by activation of poly-ADP-ribose-polymerase 1 (PARP1), an enzyme that responds to DNA damage. Upon activation PARP1 utilizes key metabolites that attenuate pathways that are normally protective for the cell. Notably, pharmacological inhibition of PARP1 or reconstitution of the metabolites rescues the changes caused by PARP1 hyperactivation and in many cases reverse the phenotypes associated with accelerated aging. This implies that modulation of PARP1 or the downstream metabolites may be a therapeutic strategy for treating accelerated aging disorders and potentially age-associated neurological decline seen in the normal population.

PMID: 27808039 [PubMed – indexed for MEDLINE]

Selective IgA Deficiency: Epidemiology, Pathogenesis, Clinical Phenotype, Diagnosis, Prognosis and Management.

March 16, 2017 By Manish Butte

Selective IgA Deficiency: Epidemiology, Pathogenesis, Clinical Phenotype, Diagnosis, Prognosis and Management.

Scand J Immunol. 2017 Jan;85(1):3-12

Authors: Yazdani R, Azizi G, Abolhassani H, Aghamohammadi A

Abstract
Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deficiency. Although more patients with SIgAD are asymptomatic, selected patients suffer from different clinical complications such as pulmonary infections, allergies, autoimmune diseases, gastrointestinal disorders and malignancy. Pathogenesis of SIgAD is still unknown; however, a defective terminal differentiation of B cells and defect in switching to IgA-producing plasma cells are presumed to be responsible. Furthermore, some cytogenic defects and monogenic mutations are associated with SIgAD. There is no specific treatment for patients with symptomatic IgA deficiency, although prophylactic antibiotic therapy along with circumstantial immunoglobulin replacement with justification and supportive care (using a product that contains minimal IgA) could be helpful for patients with a severe phenotype. The epidemiology, pathogenesis, clinical phenotype, diagnosis, prognosis, management and treatment in patients with SIgAD have been reviewed.

PMID: 27763681 [PubMed – indexed for MEDLINE]

FcμR in human B cell subsets in primary selective IgM deficiency, and regulation of FcμR and production of natural IgM antibodies by IGIV.

March 16, 2017 By Manish Butte

FcμR in human B cell subsets in primary selective IgM deficiency, and regulation of FcμR and production of natural IgM antibodies by IGIV.

Hum Immunol. 2016 Dec;77(12):1194-1201

Authors: Gupta S, Agrawal S, Gollapudi S, Kubagawa H

Abstract
IgMFcR (FcμR) are expressed on B cell and B cell subsets. Mice deficient in secreted IgM and FcμR share properties of impaired specific antibody response and autoimmunity with patient with selective IgM deficiency (SIGMD). Intravenous immunoglobulin (IGIV) regulates immune response, including modulation of IgGFc receptors. However, there are no data on the expression of FcμR in patients with SIGMD, and the effects of IGIV on FcμR. In this study, we investigated FcμR expression in naïve marginal zone (MZ), IgM memory, and class-switched memory B cells in patients with selective IgM deficiency and healthy controls. Furthermore, we examined the direct effect of IGIV on FcμR expression and on the upregulation of FcμR by TLR2 agonist (Pam3). Finally, we examined the effect of IVIG on spontaneously produced IgM and natural IgM anti-phosphorylcholine (PC) antibodies by B cells and B1 cells. FcμR expression is significantly decreased in MZ B cells in patients with SIGMD as compared to control. IGIV, at immunomodulatory concentrations, inhibited FcμR upregulation by Pam3 in MZ B cells, and IgM-depleted IGIV inhibited spontaneous secretion of natural IgM anti-PC antibodies and not total IgM by B1 cells. These data suggest that decreased FcμR expression on MZ B cells may play a role in the pathogenesis of SIGMD, and an inhibition of TLR-2-induced upregulation of FcμR by IGIV may be one of the mechanisms of its anti-inflammatory action. IGIV-induced inhibition of natural IgM antibodies may be one of the mechanisms of IGIV-induced immunoregulation.

PMID: 27751883 [PubMed – indexed for MEDLINE]

Abnormality of regulatory T cells in common variable immunodeficiency.

March 13, 2017 By Manish Butte

Abnormality of regulatory T cells in common variable immunodeficiency.

Cell Immunol. 2016 Dec 29;:

Authors: Azizi G, Hafezi N, Mohammadi H, Yazdai R, Alinia T, Tavakol M, Aghamohammadi A, Mirshafiey A

Abstract
Common variable immunodeficiency (CVID) is a heterogeneous group of primary antibody deficiencies (PAD) which is defined by recurrent infections, hypogammaglobulinemia and defects in B-cell differentiation into plasma cells and memory B cells. T cell abnormalities have also been described in CVID patients. Several studies reported that Treg frequencies and their functional characteristics are disturbed and might account for the aberrant immune responses observed in CVID patients. The aim of this review is to describe phenotypic and functional characteristics of Treg cells, and to review the literature with respect to the reported Treg defects and its association with the clinical manifestation in CVID.

PMID: 28284485 [PubMed – as supplied by publisher]

New frontiers in the therapy of primary immunodeficiency: From gene addition to gene editing.

March 9, 2017 By Manish Butte

New frontiers in the therapy of primary immunodeficiency: From gene addition to gene editing.

J Allergy Clin Immunol. 2017 Mar;139(3):726-732

Authors: Kohn DB, Kuo CY

Abstract
The most severe primary immune deficiency diseases (PIDs) have been successfully treated with allogeneic hematopoietic stem cell transplantation for more than 4 decades. However, such transplantations have the best outcomes when there is a well-matched donor available because immune complications, such as graft-versus-host disease, are greater without a matched sibling donor. Gene therapy has been developed as a method to perform autologous transplantations of a patient’s own stem cells that are genetically corrected. Through an iterative bench-to-bedside-and-back process, methods to efficiently add new copies of the relevant gene to hematopoietic stem cells have led to safe and effective treatments for several PIDs, including forms of severe combined immune deficiency, Wiskott-Aldrich syndrome, and chronic granulomatous disease. New methods for gene editing might allow additional PIDs to be treated by gene therapy because they will allow the endogenous gene to be repaired and expressed under its native regulatory elements, which are essential for genes involved in cell processes of signaling, activation, and proliferation. Gene therapy is providing exciting new treatment options for patients with PIDs, and advances are sure to continue.

PMID: 28270364 [PubMed – in process]

Norovirus infection in primary immune deficiency.

March 9, 2017 By Manish Butte

Norovirus infection in primary immune deficiency.

Rev Med Virol. 2017 Mar 08;:

Authors: Brown LK, Clark I, Brown JR, Breuer J, Lowe DM

Abstract
Norovirus is acknowledged to be a leading cause of acute gastroenteritis worldwide, and its importance as a cause of chronic infection in immune deficient hosts is increasingly recognised. Current evidence suggests that a coordinated response of innate immune mechanisms, CD8+ cytotoxicity and a humoral response, with CD4+ orchestration, is necessary for norovirus clearance. We explain how primary immune deficiency impairs these host defences and predisposes to chronic infection, associated with protracted diarrhoea, weight loss, and requirement for parenteral nutrition. The mucosal villous atrophy frequently seen in norovirus infection appears to be immune mediated, suggesting that some functional immune response is required in order for chronic norovirus infection to become symptomatic in primary immune deficiency. We provide a comprehensive summary of published cases of norovirus infection in patients with primary immune deficiency. Spontaneous viral clearance has been described; however, the majority of reported cases have had prolonged and severe illness. Treatment strategies are discussed in detail. Approaches that have been tried in patients with primary immune deficiency include exclusion diets, enteral and intravenous immunoglobulins, breast milk, immunosuppressants, ribavirin, and nitazoxanide. To date, only ribavirin has been used with apparent success to achieve clearance of chronic norovirus in primary immune deficiency, and randomised controlled trials are needed to evaluate a number of promising therapies that are discussed.

PMID: 28271593 [PubMed – as supplied by publisher]

Targeted strategies directed at the molecular defect: Toward precision medicine for select primary immunodeficiency disorders.

March 9, 2017 By Manish Butte

Targeted strategies directed at the molecular defect: Toward precision medicine for select primary immunodeficiency disorders.

J Allergy Clin Immunol. 2017 Mar;139(3):715-723

Authors: Notarangelo LD, Fleisher TA

Abstract
Primary immunodeficiency disorders (PIDs) represent a range of genetically determined diseases that typically have increased susceptibility to infections and in many cases also have evidence of immune dysregulation that often presents as autoimmunity. Most recently, the concept of gain-of-function mutations associated with PIDs has become well recognized and adds a new dimension to the understanding of this group of disorders, moving beyond the more commonly seen loss-of-function mutations. The rapidly expanding genetic defects that have been identified in patients with previously uncharacterized PIDs has opened up the potential for targeted therapy directed at the specific disease-causing abnormality. This has been driven by linking PID-specific genetic defects to the associated unique abnormalities in cellular signaling pathways amenable to directed therapies. These include agents that either block overactive or enhance underresponsive cellular pathways. Selected primary immunodeficiencies were chosen, the genetic defects of which have been recently characterized and are amenable to targeted therapy, as a reflection of the power of precision medicine.

PMID: 28270363 [PubMed – in process]

Recent Advances in Therapeutic Applications of Induced Pluripotent Stem Cells.

March 8, 2017 By Manish Butte

Recent Advances in Therapeutic Applications of Induced Pluripotent Stem Cells.

Cell Reprogram. 2017 Mar 07;:

Authors: Rami F, Naderi Beni S, Mojaver Kahnamooi M, Rahimmanesh I, Salehi AR, Salehi R

Abstract
Induced pluripotent stem (iPS) cells are generated by reprogramming of differentiated somatic cells. These cells are identical to human embryonic stem cells (hESCs) in gene expression pattern and the ability to differentiate. iPS cells can be used in in vitro modeling of diseases, testing drugs, assessing gene therapy methods, and cell therapy. Yet, the most important and promising application of iPS cells is in regenerative medicine. Regenerative medicine is a novel area in medicine aiming at the treatment of impaired or lost tissues by replacing them with functional and healthy ones. Currently, organ transplantation, which is considered the only treatment and cure for a number of diseases, is limited by shortage of organ donors and availability of the right match. Therefore, utilization of an alternative source of cells and tissues is critical in transplantation therapy. In this study, we review recent advances in therapeutic application of iPS cells in diseases where organ transplantation remains the only solution and will discuss the potential and usage of iPS cells in different areas of regenerative medicine. The primary theory of using iPS cells in regenerative medicine has brought lots of promises due to its potential for solving the immunological, social, and ethical problems of using ESCs. Nevertheless, several issues and problems have to be resolved before applying iPS cells in therapeutic applications.

PMID: 28266864 [PubMed – as supplied by publisher]

SM protein Munc18-2 facilitates transition of Syntaxin 11-mediated lipid mixing to complete fusion for T-lymphocyte cytotoxicity.

March 8, 2017 By Manish Butte

SM protein Munc18-2 facilitates transition of Syntaxin 11-mediated lipid mixing to complete fusion for T-lymphocyte cytotoxicity.

Proc Natl Acad Sci U S A. 2017 Mar 06;:

Authors: Spessott WA, Sanmillan ML, McCormick ME, Kulkarni VV, Giraudo CG

Abstract
The atypical lipid-anchored Syntaxin 11 (STX11) and its binding partner, the Sec/Munc (SM) protein Munc18-2, facilitate cytolytic granule release by cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Patients carrying mutations in these genes develop familial hemophagocytic lymphohistiocytosis, a primary immunodeficiency characterized by impaired lytic granule exocytosis. However, whether a SNARE such as STX11, which lacks a transmembrane domain, can support membrane fusion in vivo is uncertain, as is the precise role of Munc18-2 during lytic granule exocytosis. Here, using a reconstituted “flipped” cell-cell fusion assay, we show that lipid-anchored STX11 and its cognate SNARE proteins mainly support exchange of lipids but not cytoplasmic content between cells, resembling hemifusion. Strikingly, complete fusion is stimulated by addition of wild-type Munc18-2 to the assay, but not of Munc18-2 mutants with abnormal STX11 binding. Our data reveal that Munc18-2 is not just a chaperone of STX11 but also directly contributes to complete membrane merging by promoting SNARE complex assembly. These results further support the concept that SM proteins in general are part of the core fusion machinery. This fusion mechanism likely contributes to other cell-type-specific exocytic processes such as platelet secretion.

PMID: 28265073 [PubMed – as supplied by publisher]