Manish Butte

Human CARD9: A Critical Molecule of Fungal Immune Surveillance.

Front Immunol. 2018;9:1836

Authors: Drummond RA, Franco LM, Lionakis MS

Abstract
CARD9 is a signaling adaptor protein that is involved in the transduction of signals from a variety of innate pattern recognition receptors, including the C-type lectin receptors and intracellular NOD receptors and nucleic acid sensors. As a result, CARD9 has been shown in animal models to be an important regulator of immunity to bacteria, fungi, and viruses. Studies in humans with autosomal recessive CARD9 deficiency have indicated a highly specific role for this molecule in the activation of antifungal immune responses in the central nervous system, the oral mucosa, and the skin. Moreover, CARD9-dependent functions have recently been indicated to modulate the development of autoimmunity, inflammatory bowel diseases, and cancer. In this mini-review, we highlight the recent studies that have identified several novel functions of CARD9 in various disease contexts, and we summarize the contemporary understanding of the genetics and immunology of human CARD9 deficiency.

PMID: 30127791 [PubMed – in process]

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Disruption of an antimycobacterial circuit between dendritic and helper T cells in human SPPL2a deficiency.

Nat Immunol. 2018 Aug 20;:

Authors: Kong XF, Martinez-Barricarte R, Kennedy J, Mele F, Lazarov T, Deenick EK, Ma CS, Breton G, Lucero KB, Langlais D, Bousfiha A, Aytekin C, Markle J, Trouillet C, Jabot-Hanin F, Arlehamn CSL, Rao G, Picard C, Lasseau T, Latorre D, Hambleton S, Deswarte C, Itan Y, Abarca K, Moraes-Vasconcelos D, Ailal F, Ikinciogullari A, Dogu F, Benhsaien I, Sette A, Abel L, Boisson-Dupuis S, Schröder B, Nussenzweig MC, Liu K, Geissmann F, Tangye SG, Gros P, Sallusto F, Bustamante J, Casanova JL

Abstract
Human inborn errors of IFN-γ immunity underlie mycobacterial diseases. We describe patients with Mycobacterium bovis (BCG) disease who are homozygous for loss-of-function mutations of SPPL2A. This gene encodes a transmembrane protease that degrades the N-terminal fragment (NTF) of CD74 (HLA invariant chain) in antigen-presenting cells. The CD74 NTF therefore accumulates in the HLA class II+ myeloid and lymphoid cells of SPPL2a-deficient patients. This toxic fragment selectively depletes IL-12- and IL-23-producing CD1c+ conventional dendritic cells (cDC2s) and their circulating progenitors. Moreover, SPPL2a-deficient memory TH1* cells selectively fail to produce IFN-γ when stimulated with mycobacterial antigens in vitro. Finally, Sppl2a-/- mice lack cDC2s, have CD4+ T cells that produce small amounts of IFN-γ after BCG infection, and are highly susceptible to infection with BCG or Mycobacterium tuberculosis. These findings suggest that inherited SPPL2a deficiency in humans underlies mycobacterial disease by decreasing the numbers of cDC2s and impairing IFN-γ production by mycobacterium-specific memory TH1* cells.

PMID: 30127434 [PubMed – as supplied by publisher]

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Hyperactivated PI3Kδ promotes self and commensal reactivity at the expense of optimal humoral immunity.

Nat Immunol. 2018 Aug 20;:

Authors: Preite S, Cannons JL, Radtke AJ, Vujkovic-Cvijin I, Gomez-Rodriguez J, Volpi S, Huang B, Cheng J, Collins N, Reilley J, Handon R, Dobbs K, Huq L, Raman I, Zhu C, Li QZ, Li MO, Pittaluga S, Uzel G, Notarangelo LD, Belkaid Y, Germain RN, Schwartzberg PL

Abstract
Gain-of-function mutations in the gene encoding the phosphatidylinositol-3-OH kinase catalytic subunit p110δ (PI3Kδ) result in a human primary immunodeficiency characterized by lymphoproliferation, respiratory infections and inefficient responses to vaccines. However, what promotes these immunological disturbances at the cellular and molecular level remains unknown. We generated a mouse model that recapitulated major features of this disease and used this model and patient samples to probe how hyperactive PI3Kδ fosters aberrant humoral immunity. We found that mutant PI3Kδ led to co-stimulatory receptor ICOS-independent increases in the abundance of follicular helper T cells (TFH cells) and germinal-center (GC) B cells, disorganized GCs and poor class-switched antigen-specific responses to immunization, associated with altered regulation of the transcription factor FOXO1 and pro-apoptotic and anti-apoptotic members of the BCL-2 family. Notably, aberrant responses were accompanied by increased reactivity to gut bacteria and a broad increase in autoantibodies that were dependent on stimulation by commensal microbes. Our findings suggest that proper regulation of PI3Kδ is critical for ensuring optimal host-protective humoral immunity despite tonic stimulation from the commensal microbiome.

PMID: 30127432 [PubMed – as supplied by publisher]

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STAT3-Deficient hyperimmunoglobulin E syndrome: report of a case with orofacial granulomatosis-like disease.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Jul 21;:

Authors: Carey B, Mercadante V, Fedele S, Glover M, Cale C, Porter S

Abstract
Hyperimmunoglobulin E syndrome (HIES) is a rare heterogeneous primary immunodeficiency disorder characterized by infections of the lung and skin, elevated serum immunoglobulin E, and involvement of soft and bony tissues. Autosomal dominant HIES and related disorders are caused by defects in the Janus activated kinase-signal transducer and activator of transcription signaling pathway, leading to reduced numbers of T helper cell type 17 and impaired production of interleukin (IL)-17 A, IL-17 F, and IL-22. In addition, neutrophils have chemotactic defects, resulting in impaired responses at skin and lung sites. We report here a case of orofacial granulomatosis-like disease in a teenage boy ultimately found to have autosomal dominant HIES caused by a heterozygous mutation in the STAT3 gene.

PMID: 30126807 [PubMed – as supplied by publisher]

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The Iceberg Map of germline mutations in childhood cancer: focus on primary immunodeficiencies.

Curr Opin Pediatr. 2018 Aug 16;:

Authors: Kindler O, Quehenberger F, Benesch M, Seidel MG

Abstract
PURPOSE OF REVIEW: The risk of cancer is higher, and its outcome is worse in patients with primary immunodeficiency (PID) than in members of the general population. Thus, the inter-relationship of malignant diseases with PIDs requires more study.
RECENT FINDINGS: Large genetic screens identified a vast number of germline mutations in childhood cancer patient samples. Although TP53 was the most frequent single gene identified as mutated, many PID disorders like DNA repair defects are among the inborn causes of childhood cancer. We provide a comprehensive analysis of compiled data from seven recent studies that focused on germline genetic landscapes and preexisting conditions in pediatric oncology. As potentially causal germline variants were identified in ≈8% of malignancies in children and adolescents, we visualized this proportion as the ‘tips of the icebergs’. The results of additional network analyses showed the shared patterns of germline mutations in various malignancies and yielded a spatial distribution of the ‘icebergs’.
SUMMARY: The ‘iceberg map of germline mutations in childhood cancers’ was created to increase the awareness of the inborn genetic underpinnings of childhood malignancies and their relationships with immunodeficiencies. Needs and perspectives of clinical immunologists and pediatric oncologists to both improve patient care and guide research at this critical interface are discussed. VIDEO ABSTRACT.

PMID: 30124581 [PubMed – as supplied by publisher]

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Timing of infections in patients with primary immunodeficiencies treated with intravenous immunoglobulin (IVIg).

Allergy Asthma Clin Immunol. 2018;14:35

Authors: Gill PK, Betschel SD

Abstract
Purpose: Patients with common variable immune deficiency and X-linked agammaglobulinemia are unable to produce their own antibodies thus leading to a higher incidence of recurrent infections, particularly those involving the sinuses and lungs. Treatment with intravenous immunoglobulin therapy aims to reduce the incidence of infections; however, as serum IgG approaches its trough during the third and fourth week after infusion, we hypothesized that the rate of infection would be higher during this time period.
Methods: Patients with a diagnosis of either common variable immunodeficiency (CVID) or X-linked agammaglobulinemia (XLA) treated with intravenous immunoglobulin (IVIg) were analyzed in a prospective cohort study. Data was obtained as to the timing of symptom onset post infusion, the type of infection, as well as timing of the initiation of antibiotics. Descriptive analyses were conducted to explore the patterns of the data at each month and then over the course of the study year.
Results: Twenty-three patients with a diagnosis of either CVID (n = 22), or XLA (n = 1) were enrolled with a mean follow duration of 11.3 months. The mean number of days to infection after IVIg infusion, the primary endpoint, was 17.0 days with the most common infections reported as sinusitis and upper respiratory tract infections. There was no statistically significant difference (p = 0.70) in the rates of infection when considering the weeks post-infusion.
Conclusions: We believe that this pilot study is the first reported prospective study to examine the timing of infections after IVIg infusion in individuals with CVID and XLA. Further multi-centered research with a larger sample size is required into the comparison of infection rates in primary immunodeficiency patients treated with IVIg versus subcutaneous immunoglobulin therapy, where serum IgG levels remain at steady state.

PMID: 30123298 [PubMed]

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Two siblings with PRKDC defect who presented with cutaneous granulomas and review of the literature.

Clin Immunol. 2018 Aug 16;:

Authors: Esenboga S, Akal C, Karaatmaca B, Erman B, Dogan S, Orhan D, Boztug K, Ayvaz D, Tezcan İ

Abstract
V(D)J recombination, during which recognition and repair of broken DNA chains are accomplished by non-homologous end joining pathway, is a critical process in B and T cell development.Null mutations of each enzyme or protein of this pathway result in T- B- NK+ severe combined immunodeficiency whereas hypomorphic mutations result in atypical(leaky)severe combined immunodeficiency forms. We present two siblings with PRKDC (Protein Kinase, DNA-Activated, Catalytic Polypeptide) mutation who presented with granulomatous skin lesions and recurrent lung infections. Primary immune deficiencies may initially present with skin findings. Disruption in central and peripheral B-cell tolerance and impaired intrathymic T-cell maturation,a central player in T-cell tolerance, have been identified as the mechanism of autoimmunity and granuloma seen in patients. The variation in clinical phenotypes of patients with PRKDC mutation suggests that additional factors such as modifying genes, epigenetic and environmental factors may affect the severity and clinical phenotype of the disease. Functional studies during the follow-up and evaluation before and after hematopoeitic stem cell transplantation will hopefully increase our knowledge about the autoimmune and inflammatory process of the disease spectrum.

PMID: 30121298 [PubMed – as supplied by publisher]

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Simulation of the Dynamics of Primary Immunodeficiencies in B Cells.

Front Immunol. 2018;9:1785

Authors: Teku GN, Vihinen M

Abstract
Primary immunodeficiencies (PIDs) are a group of over 300 hereditary, heterogeneous, and mainly rare disorders that affect the immune system. Various aspects of immune system and PID proteins and genes have been investigated and facilitate systems biological studies of effects of PIDs on B cell physiology and response. We reconstructed a B cell network model based on data for the core B cell receptor activation and response processes and performed semi-quantitative dynamic simulations for normal and B cell PID failure modes. The results for several knockout simulations correspond to previously reported molecular studies and reveal novel mechanisms for PIDs. The simulations for CD21, CD40, LYN, MS4A1, ORAI1, PLCG2, PTPRC, and STIM1 indicated profound changes to major transcription factor signaling and to the network. Significant effects were observed also in the BCL10, BLNK, BTK, loss-of-function CARD11, IKKB, MALT1, and NEMO, simulations whereas only minor effects were detected for PIDs that are caused by constitutively active proteins (PI3K, gain-of-function CARD11, KRAS, and NFKBIA). This study revealed the underlying dynamics of PID diseases, confirms previous observations, and identifies novel candidates for PID diagnostics and therapy.

PMID: 30116248 [PubMed – in process]

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Clinical Manifestation of Hyper IgE Syndrome Including Otitis Media.

Curr Allergy Asthma Rep. 2018 Aug 15;18(10):51

Authors: Wu J, Hong L, Chen TX

Abstract
PURPOSE OF REVIEW: The hyper IgE syndromes (HIES) comprise a group of rare primary immunodeficiency disorders (PIDDs), which are characterized by extremely high serum IgE levels, eczema, recurrent skin and pulmonary infections. Both autosomal dominant (AD) HIES due to STAT3 mutations and autosomal recessive (AR) HIES due to PGM3, SPINK5, DOCK8 and TKY2 mutations have been reported. Here, we aim to summarize and compare the major clinical manifestations of different subtypes of HIES. We will also discuss otitis media, which usually do not get enough attention in HIES. Update and familiarity with these clinical features will help to make a better diagnose, assessment and treatment of HIES.
RECENT FINDINGS: Although hyper serum IgE levels have been identified in PGM3 deficiency and Comel-Netherton syndrome, PGM3 and SPINK5 genes were not included in the list of genetic etiologies of AR-HIES by the Expert Committee of the International Union of Immunological Societies until 2015. The identification of these HIES-causing genes greatly promoted the pathogenic mechanism studies of HIES. Also, in recent years, more clinical manifestations, which were often not of concern in HIES patients, have been shown to be highly related to HIES. For example, a significantly high frequency of vascular and gastrointestinal abnormities has been reported in STAT3-deficient AD-HIES patients. These new findings might help to provide new clues to the functional study of these HIES-related genes. This review summarizes and compares the major clinical manifestations of different subtypes of HIES, and we suggest that the incidence and severity of otitis media should not be underestimated in HIES patients.

PMID: 30112673 [PubMed – in process]

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