Research

Two Faces of LRBA Deficiency in Siblings: Hypogammaglobulinemia and Normal Immunoglobulin Levels.

J Investig Allergol Clin Immunol. 2018;28(1):48-50

Authors: Azizi G, Abolhassani H, Habibi S, Rahamooz T, Mohammadi H, Jafarnezhad-Ansariha F, Mortazavi-Jahromi SS, Yazdani R, Aghamohammadi A

PMID: 29461210 [PubMed – in process]

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First Occurrence of Plasmablastic Lymphoma in Adenosine Deaminase-Deficient Severe Combined Immunodeficiency Disease Patient and Review of the Literature.

Front Immunol. 2018;9:113

Authors: Migliavacca M, Assanelli A, Ponzoni M, Pajno R, Barzaghi F, Giglio F, Ferrua F, Frittoli M, Brigida I, Dionisio F, Nicoletti R, Casiraghi M, Roncarolo MG, Doglioni C, Peccatori J, Ciceri F, Cicalese MP, Aiuti A

Abstract
Adenosine deaminase-deficient severe combined immunodeficiency disease (ADA-SCID) is a primary immune deficiency characterized by mutations in the ADA gene resulting in accumulation of toxic compounds affecting multiple districts. Hematopoietic stem cell transplantation (HSCT) from a matched donor and hematopoietic stem cell gene therapy are the preferred options for definitive treatment. Enzyme replacement therapy (ERT) is used to manage the disease in the short term, while a decreased efficacy is reported in the medium-long term. To date, eight cases of lymphomas have been described in ADA-SCID patients. Here we report the first case of plasmablastic lymphoma occurring in a young adult with ADA-SCID on long-term ERT, which turned out to be Epstein-Barr virus associated. The patient previously received infusions of genetically modified T cells. A cumulative analysis of the eight published cases of lymphoma from 1992 to date, and the case here described, reveals a high mortality (89%). The most common form is diffuse large B-cell lymphoma, which predominantly occurs in extra nodal sites. Seven cases occurred in patients on ERT and two after haploidentical HSCT. The significant incidence of immunodeficiency-associated lymphoproliferative disorders and poor survival of patients developing this complication highlight the priority in finding a prompt curative treatment for ADA-SCID.

PMID: 29456531 [PubMed]

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Donor Genotype in the Interleukin-7 Receptor α-Chain Predicts Risk of Graft-versus-Host Disease and Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation.

Front Immunol. 2018;9:109

Authors: Kielsen K, Enevold C, Heilmann C, Sengeløv H, Pedersen AE, Ryder LP, Müller K

Abstract
The efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute and chronic graft-versus-host disease (aGVHD and cGVHD) and viral infections due to long-lasting immunodeficiency. Interleukin-7 (IL-7) is a cytokine essential for de novo T cell generation in thymus and peripheral T cell homeostasis. In this study, we investigated the impact of the single nucleotide polymorphism rs6897932 in the IL-7 receptor α-chain (IL-7Rα) which has previously been associated with several autoimmune diseases. We included 460 patients undergoing allogeneic HSCT after a myeloablative conditioning. Patients had a median age of 26.3 years (0.3-67.0 years), and 372 (80.9%) underwent HSCT for malignant diseases. Donors were matched sibling donors (n = 147), matched unrelated donors (n = 244) or mismatched unrelated donors (n = 69), and the stem cell source were either bone marrow (n = 329) or peripheral blood (n = 131). DNA from donors was genotyped for the IL-7Rα single nucleotide polymorphism (SNP) rs6897932 using an allele-specific primer extension assay (CC: n = 252, CT: n = 178, TT: n = 30). The donor T allele was associated with a higher risk of grades III-IV aGVHD (HR = 2.0, 95% CI = 1.1-3.8, P = 0.034) and with significantly increased risk of extensive cGVHD (HR = 2.0, 95% CI = 1.1-3.6, P = 0.025) after adjustment for potential risk factors. In addition, the TT genotype was associated with a higher risk of cytomegalovirus (CMV) infection post-transplant (HR = 2.4, 95% CI = 1.2-4.3, P = 0.0068). Numbers of T cells were significantly higher on day +60 in patients receiving a rs6897932 TT graft (CD3+: 109% increase, P = 0.0096; CD4+: 64% increase, P = 0.038; CD8+: 133% increase, P = 0.011). Donor heterozygosity for the T allele was associated with inferior overall survival (HR = 1.7, 95% CI = 1.2-2.3, P = 0.0027) and increased treatment-related mortality (HR = 2.3, 95% CI = 1.3-4.0, P = 0.0047), but was not associated with the risk of relapse (P = 0.35). In conclusion, the IL-7Rα rs6897932 genotype of the donor is predictive of aGVHD and cGVHD, CMV infection, and mortality following HSCT. These findings indicate that IL-7Rα SNP typing of donors may optimize donor selection and facilitate individualization of treatment in order to limit treatment-related complications.

PMID: 29456530 [PubMed]

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Caveolin-1: The Unnoticed Player in TCR and BCR Signaling.

Adv Immunol. 2018;137:83-133

Authors: Fiala GJ, Minguet S

Abstract
T and B lymphocytes are key players of the adaptive immune system. They recognize pathogenic cues via the T cell antigen receptor (TCR) and the B cell antigen receptor (BCR) to get activated and execute their protective function. TCR and BCR signaling are initiated at the plasma membrane and subsequently propagated into the cell, ultimately leading to cell activation and a protective immune response. However, inappropriate activation of T and B cells can be detrimental to the host resulting in autoimmune disorders, immunodeficiencies, and cancer. The TCR and BCR are located at the plasma membrane, which composition is highly heterogenic. Membrane compartmentalization based on specific lipid-lipid and protein-lipid interactions has raised the interest of the scientific community, converting the plasma membrane into an active player in the initiation of signaling and adding an additional layer of regulation to our current understanding of the functioning of antigen receptors. Caveolin-1 is an integral membrane protein and a crucial component of caveolae. It has been long thought that lymphocytes lack Caveolin-1 expression, due to the absence of detectable caveolae in lymphocytes and the failure to detect Caveolin-1 in T and B cell lines. However, Caveolin-1 is expressed at low levels in primary lymphocytes, and recent studies have shown the importance of Caveolin-1 for the basal membrane organization of the BCR and the TCR as well as their reorganization upon activation. Here, we review our current understanding of the initial signaling events of TCR and BCR activation with respect to receptor compartmentalization on the plasma membrane and with special emphasis on the previously unnoticed role of Caveolin-1.

PMID: 29455848 [PubMed – in process]

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Role of Bruton’s tyrosine kinase in B cells and malignancies.

Mol Cancer. 2018 Feb 19;17(1):57

Authors: Pal Singh S, Dammeijer F, Hendriks RW

Abstract
Bruton’s tyrosine kinase (BTK) is a non-receptor kinase that plays a crucial role in oncogenic signaling that is critical for proliferation and survival of leukemic cells in many B cell malignancies. BTK was initially shown to be defective in the primary immunodeficiency X-linked agammaglobulinemia (XLA) and is essential both for B cell development and function of mature B cells. Shortly after its discovery, BTK was placed in the signal transduction pathway downstream of the B cell antigen receptor (BCR). More recently, small-molecule inhibitors of this kinase have shown excellent anti-tumor activity, first in animal models and subsequently in clinical studies. In particular, the orally administered irreversible BTK inhibitor ibrutinib is associated with high response rates in patients with relapsed/refractory chronic lymphocytic leukemia (CLL) and mantle-cell lymphoma (MCL), including patients with high-risk genetic lesions. Because ibrutinib is generally well tolerated and shows durable single-agent efficacy, it was rapidly approved for first-line treatment of patients with CLL in 2016. To date, evidence is accumulating for efficacy of ibrutinib in various other B cell malignancies. BTK inhibition has molecular effects beyond its classic role in BCR signaling. These involve B cell-intrinsic signaling pathways central to cellular survival, proliferation or retention in supportive lymphoid niches. Moreover, BTK functions in several myeloid cell populations representing important components of the tumor microenvironment. As a result, there is currently a considerable interest in BTK inhibition as an anti-cancer therapy, not only in B cell malignancies but also in solid tumors. Efficacy of BTK inhibition as a single agent therapy is strong, but resistance may develop, fueling the development of combination therapies that improve clinical responses. In this review, we discuss the role of BTK in B cell differentiation and B cell malignancies and highlight the importance of BTK inhibition in cancer therapy.

PMID: 29455639 [PubMed – in process]

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Low Serum IgE Is a Sensitive and Specific Marker for Common Variable Immunodeficiency (CVID).

J Clin Immunol. 2018 Feb 17;:

Authors: Lawrence MG, Palacios-Kibler TV, Workman LJ, Schuyler AJ, Steinke JW, Payne SC, McGowan EC, Patrie J, Fuleihan RL, Sullivan KE, Lugar PL, Hernandez CL, Beakes DE, Verbsky JW, Platts-Mills TAE, Cunningham-Rundles C, Routes JM, Borish L

Abstract
Although small prior studies have suggested that IgE can be low in common variable immunodeficiency (CVID), the workup for patients with recurrent infections and suspected hypogammaglobulinemia does not include the routine measurement of serum IgE. We sought to test the hypothesis that low/undetectable serum IgE is characteristic of CVID by comparing the frequency of low/undetectable serum IgE in healthy controls and patients with CVID. We measured total serum IgE in a large multi-center cohort of patients with CVID (n = 354) and compared this to large population-based cohorts of children and adults. We further compared IgE levels in patients with CVID to those with other forms of humoral immunodeficiency, and in a subset, measured levels of allergen-specific serum IgE and IgG subclasses. Lastly, we evaluated for the presence of IgE in commercially available immunoglobulin replacement therapy (IgRT) products. An undetectable serum IgE (< 2 IU/ml) occurs in only 3.3% (95% CI, 1.9-5.7%) of the general population. In contrast, an undetectable IgE occurs in 75.6% (95% CI, 65.6-85.7%) of patients with CVID. Conversely, a high IgE (> 180 IU/ml) is very uncommon in CVID (0.3% of patients). IgE is > 2 IU/ml in 91.2% of patients with secondary hypogammaglobulinemia, and thus, an IgE < LLOD is suggestive of a primary humoral immunodeficiency. Allergen-specific IgE is not detectable in 96.5% of patients with CVID. Sufficient quantities of IgE to change the total serum IgE are not contained in IgRT. The IgG1/IgG4 ratio is increased in subjects with low IgE, regardless of whether they are controls or have CVID. These findings support the routine measurement of serum IgE in the workup of patients with hypogammaglobulinemia.

PMID: 29453744 [PubMed – as supplied by publisher]

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Seminars in Cell and Developmental Biology Human Dendritic Cell Immunodeficiencies.

Semin Cell Dev Biol. 2018 Feb 13;:

Authors: Bigley V, Cytlak U, Collin M

Abstract
The critical functions of dendritic cells (DCs) in immunity and tolerance have been demonstrated in many animal models but their non-redundant roles in humans are more difficult to probe. Human primary immunodeficiency (PID), resulting from single gene mutations, may result in DC deficiency or dysfunction. This relatively recent recognition illuminates the in vivo role of human DCs and the pathophysiology of the associated clinical syndromes. In this review, the development and function of DCs as established in murine models and human in vitro systems, is discussed. This forms the basis of predicting the effects of DC deficiency in vivo and understanding the consequences of specific mutations on DC development and function. DC deficiency syndromes are associated with heterozygous GATA2 mutation, bi-allelic and heterozygous IRF8 mutation and heterozygous IKZF1 mutation. The intricate involvement of DCs in the balance between immunity and tolerance is leading to increased recognition of their involvement in a number of other immunodeficiency and autoimmune conditions. Owing to the precise control of transcription factor gene expression by super-enhancer elements, phenotypic anomalies are relatively commonly caused by heterozygous mutations.

PMID: 29452225 [PubMed – as supplied by publisher]

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Immunoglobulin E-an Innocent Bystander in Host Defense?

J Clin Immunol. 2018 Feb 15;:

Authors: Zhang Q, Seppänen MRJ

PMID: 29450679 [PubMed – as supplied by publisher]

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Intestinal immunity suppresses carrying capacity of rats for the model tapeworm, Hymenolepis diminuta.

Parasitol Int. 2018 Feb 12;:

Authors: Ohno T, Kai T, Miyasaka Y, Maruyama H, Ishih A, Kino H

Abstract
Hymenolepis diminuta is a parasitic tapeworm of the rat small intestine and is recognized as a useful model for the analysis of cestode-host interactions. In this study, we analyzed factors affecting the biomass of the tapeworm through use of rat strains carrying genetic mutations, namely X-linked severe combined immunodeficiency (xscid; T, B and NK cells deficiency), nude (rnu; T cell deficiency), and mast cell deficient rats. The worm biomass of F344-xscid rats after infection with 5 cysticercoids was much larger than control F344 rats from 3 to 8 weeks. The biomass of F344-rnu rats was also larger than the controls, but was intermediate between F344-xscid and control rats. These observations demonstrated that host immunity can control the maximal tapeworm biomass, i.e., carrying capacity, of the rat small intestine. Both T cell and other immune cells (B and NK cells) have roles in determining the carrying capacity of tapeworms. Total worm biomass and worm numbers in mast cell deficient rats (WsRC-Ws/Ws) were not significantly different from control WsRC-+/+ rats after 3 and 6 weeks of primary infection. Mast cell deficient rats displayed reinfection resistance for worm biomass but not worm expulsion. These findings suggest that the mast cell has a role for controlling the biomass of this tapeworm in reinfection alone, but does not affect the rate of worm expulsion. Overall, our findings indicate that the mast cell is not a major effector cell for the control of the carrying capacity of tapeworms. The identity of the major effector cell remains unknown.

PMID: 29448016 [PubMed – as supplied by publisher]

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Neutrophils drive type-I interferon production and autoantibodies in Wiskott-Aldrich syndrome.

J Allergy Clin Immunol. 2018 Feb 12;:

Authors: Cervantes-Luevano KE, Caronni N, Castiello MC, Fontana E, Piperno G, Naseem A, Uva P, Bosticardo M, Marcovecchio GE, Notarangelo LD, Cicalese MP, Aiuti A, Villa A, Benvenuti F

Abstract
BACKGROUND: Wiskott-Aldrich syndrome (WAS) is a rare primary immunodeficiency caused by mutations in WASp, a key regulator of cytoskeletal dynamics in hematopoietic cells. A high proportion of patients develop autoimmunity due to a breakdown in T and B cell tolerance. Moreover, excessive production of type-I interferon by plasmacytoid DCs contribute to autoimmune signs, however, the factors that triggers excessive innate activation have not been defined.
OBJECTIVE: Neutrophils extracellular traps (NETs) emerged as major initiating factors in diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In this study, we explored the possible involvement of aberrant neutrophil functions in WAS.
METHODS: We evaluated the expression of a set of granulocyte genes associated with NETs in a cohort of WAS patients and the presence of NET-inducers in sera. Using a mouse model of WAS, we analyzed NET release by WASp-null neutrophils, and we evaluated the composition and homeostasis of neutrophils in vivo. By means of depletion experiments, we assessed the impact of neutrophils in promoting inflammation and reactivity against auto-antigens.
RESULTS: Transcripts of genes encoding neutrophil enzymes and antimicrobial peptides were elevated in granulocytes of WAS patients, and serum soluble factors triggered NET release. WASp-null neutrophils showed increased spontaneous NETosis, induced type-I interferon production by plasmacytoid DCs (pDCs), and activated B cells via BAFF. Consistently, their depletion abolished constitutive pDCs activation, normalized circulating IFN-I levels and, importantly, abolished production of autoantibodies directed against dsDNA, nucleosomes and MPO.
CONCLUSIONS: These findings reveal that neutrophils are involved in the pathogenic loop that causes excessive activation of innate cells and autoreactive B cell, thus identifying novel mechanisms that contribute to the autoimmunity of WAS.

PMID: 29447842 [PubMed – as supplied by publisher]

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