Chronic granulomatous disease

Serum Biomarkers for Early Diagnosis of Chinese X-CGD Children: Case Reports and a Literature Review

Since X-linked chronic granulomatosis disease (X-CGD) exhibits no specific clinical symptoms at an early stage, early diagnosis is difficult and depends predominantly on neonatal screening. Therefore, the aim of this study was to explore routine biomarkers for X-CGD in children and provide clues for early diagnosis. The cases of 10 children with X-CGD diagnosed at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from 2013 to 2016 and 122 Chinese children with X-CGD reported in the literature were summarized. Serum biomarkers and clinical symptoms at acute infection were organized. A total of 132 children with X-CGD were enrolled in this study. For 55.8% of the patients, the diagnosis was delayed more than one year after the onset of the first symptoms because no typical clinical symptoms manifested. Children with X-CGD at an acute infection stage showed three recurrent signs in terms of serum biomarkers: (1) the total number of white blood cells (especially N%) was increased significantly, accompanied by anemia in some cases; (2) C-reactive protein (CRP) levels were increased significantly; and (3) most of the patients exhibited very high serum IgG levels (>12 g/L). Diagnosis of X-CGD at an early age is difficult because of its nonspecific clinical features. Our study suggested children with X-CGD suffering acute infection show increases in three typical serum biomarkers, which can provide clues for early diagnosis.

Clinical Features and Genetic Analysis of 48 Patients with Chronic Granulomatous Disease in a Single Center Study from Shanghai, China (2005-2015): New Studies and a Literature Review

Chronic Granulomatous Disease (CGD) is a rare inherited primary immunodeficiency, which is characterized by recurrent infections due to defective phagocyte NADPH oxidase enzyme. Nowadays, little is known about Chinese CGD patients. Here we report 48 CGD patients in our single center study, which is the largest cohort study from Mainland China. The ratio of male to female was 11 : 1. The mean onset age was 0.29 years old, and 52% patients had an onset within the 1st month of life. The mean diagnosis age was 2.24 years old. 11 patients (23%) had died with an average age of 2.91 years old. 13 patients (28%) had positive family histories. The most prevalent infectious sites were the lungs (77%), followed by gastrointestinal tract (54%), lymph nodes (50%), and skin (46%). In addition, septicopyemia, thrush, and hepatosplenomegaly were also commonly observed, accounting for 23%, 23%, and 40% of the cases. Lesions due to BCG vaccination occurred in more than half of the patients. X-linked CGD due to CYBB gene mutations accounted for 75% of the cases, and 11 of them were novel mutations. Autosomal recessive inheritance accounted for 6% patients, including 1 patient with CYBA, 1 with NCF1, and 1 with NCF2 gene mutations.

In vitro Study of BCG Granuloma Macrophage Morphofunctional Status

We studied the morphofunctional and cytophysiological status of macrophages emigrating from BCG granulomas forming in spleen and free splenic macrophages that are not associated with granulomas. The experimental BCG granulomatosis was induced by intravenous injection of male BALB/c mice with BCG vaccine mycobacteria. The number of granulomas in spleen, their diameter, the proportion of granuloma macrophages with mycobacteria, the number of mycobacteria in granuloma macrophages, the proportion of live bacteria in granuloma macrophages and the number of granulomas macrophages capable of expressing IL-1α, TNF-α, GM-CSF were evaluated. BCG granulomas were explanted in cultures in vitro. Fractions, containing free splenic macrophages from BCG-infected animals, were explanted in separate cultures in vitro. The phagocytic activity of macrophages that migrated from BCG granulomas explanted in cultures one month after mycobacterial infection of mice, was much higher than those of splenic macrophages of intact mice. The phagocytic activity of free macrophages and macrophages from granulomas decreased with time after infection. By contrast, the antimycobacterial activity of free splenic macrophages and macrophages from BCG granulomas increased with time after infection. The correlational analysis showed that there are different correlational relationships between the number of granuloma macrophages expressing IL-1α, TNF-α, GM-CSF and phagocytic activity of macrophages from BCG granulomas. The results of the study are important for understanding the molecular and cellularmechanisms of development of chronic granulomatous inflammation induced by mycobacterial infection.

Robust T cell responses to aspergillosis in chronic granulomatous disease: implications for immunotherapy

Chronic granulomatous disease (CGD) patients are highly susceptible to invasive aspergillosis and might benefit from aspergillus-specific T cell immunotherapy, which has shown promise in treating those with known T cell defects such as haematopoietic stem cell transplant (HSCT) recipients. But whether such T cell defects contribute to increased risks for aspergillus infection in CGD is unclear. Hence, we set out to characterize the aspergillus-specific T cell response in CGD. In murine CGD models and in patients with CGD we showed that the CD4(+) T cell responses to aspergillus were unimpaired: aspergillus-specific T cell frequencies were even elevated in CGD mice (P < 0·01) and humans (P = 0·02), compared to their healthy counterparts. CD4-depleted murine models suggested that the role of T cells might be redundant because resistance to aspergillus infection was conserved in CD4(+) T cell-depleted mice, similar to wild-type animals. In contrast, mice depleted of neutrophils alone or neutrophils and CD4(+) T cells developed clinical and pathological evidence of pulmonary aspergillosis and increased mortality (P < 0·05 compared to non-depleted animals). Our findings that T cells in CGD have a robust aspergillus CD4(+) T cell response suggest that CD4(+) T cell-based immunotherapy for this disease is unlikely to be beneficial.

Aspergillus tanneri sp. nov., a new pathogen that causes invasive disease refractory to antifungal therapy

The most common cause of invasive aspergillosis (IA) in patients with chronic granulomatous disease (CGD) is Aspergillus fumigatus followed by A. nidulans; other aspergilli rarely cause the disease. Here we review two clinical cases of fatal IA in CGD patients and describe a new etiologic agent of IA refractory to antifungal therapy. Unlike typical IA caused by A. fumigatus, the disease caused by the new species was chronic and spread from the lung to multiple adjacent organs. Mycological characteristics and the phylogenetic relationship with other aspergilli based on the sequence analysis of Mcm7, RPB2, and Tsr1 indicated that the new species, which we named as A. tanneri, belongs to Aspergillus section Circumdati. The species has a higher amphotericin B, voriconazole, and itraconazole MIC and causes more chronic infection in CGD mice than A. fumigatus. This is the first report documenting IA in CGD patients caused by a species belonging to the Aspergillus section Circumdati that is inherently resistant to azoles and amphotericin B. Unlike the results seen with many members of Aspergillus section Circumdati, ochratoxin was not detected in filtrates of cultures grown in various media. Our phenotypic and genetic characterization of the new species and the case reports will assist future diagnosis of infection caused by A. tanneri and lead to more appropriate patient management.

A Case of Chronic Granulomatous Disease with a Necrotic Mass in the Bronchus: A Case Report and a Review of Literature

Chronic granulomatous disease is a rare phagocytic disorder with recurrent, severe bacterial and fungal infections. We describe an unusual case of chronic granulomatous disease manifesting as an invasive pulmonary aspergillosis with an obstructive necrotic mass at the right middle bronchus. The patient was successfully treated with a bronchoscopic intervention for the removal of the obstructive mass and a medical therapy.

Coupling of 6-phosphogluconate dehydrogenase with NADPH oxidase in neutrophils: Nox2 activity regulation by NADPH availability

It is well known that activation of the phagocyte NADPH oxidase requires the association of cytosolic proteins (p67-phox, p47-phox, p40-phox, and Rac) with the membrane cytochrome b(558), leading to its conformation change. Recently, the phagocyte NADPH oxidase complex was isolated in a constitutively active form. In this complex, 6-phosphogluconate dehydrogenase (6PGDH), an enzyme involved in the production of intracellular NADPH, was identified. This protein was absent from the oxidase complex isolated from B lymphocytes, suggesting a specific interaction with the neutrophil NADPH oxidase. To clarify the implication of 6PGDH in the NADPH oxidase activity, a siRNA approach was conducted in neutrophil-like PLB985 cells. NADPH oxidase activity of siRNA-transfected cells was shown to be decreased. Similar results were obtained in vitro, after reconstitution of oxidase activity with subcellular fractions isolated from siRNA-transfected cells. Interestingly, the Michaelis constant (K(m)) of Nox2 for NADPH increases in 6PGDH-depleted cells. Moreover, 6PGDH coimmunoprecipitated with oxidase cytosolic factors from cytosol of stimulated cells. Data suggested that the affinity of Nox2 for NADPH is increased in the presence of 6PGDH on cell stimulation. The present work proposes a new way of NADPH oxidase activity regulation by modulating Nox2 affinity for NADPH.

Generation of a conditional null allele of NADPH oxidase activator 1 (NOXA1)

NADPH oxidase complexes are multiprotein assemblies that generate reactive oxygen species in a variety of mammalian tissues. The canonical phagocytic oxidase consists of a heterodimeric, enzymatic core comprised of the transmembrane proteins, CYBB andCYBA and is regulated, in part, by an "organizing" function of NCF1 and an "activating" activity of NCF2. In contexts outside of the phagocyte, these regulatory functions may be encoded not only by NCF1 and NCF2, but also alternatively by their respective paralogues, NOXO1 and NOXA1. To allow tissue-specific dissection of Noxa1 function in mouse, we have generated an allele of Noxa1 suitable for conditional inactivation. Moreover, by crossing Noxa1 conditional allele carriers to B6.129S4-Meox2(tm1(Cre)Sor)/J mice, we have generated first, Noxa1-null heterozygotes, and ultimately, Noxa1-null homozygotes. Through the thoughtful use of tissue-specific, Cre-expressing mouse strains, the Noxa1 conditional allele will offer insight into the roles of NOXA1 in the variety of tissues in which it is expressed.

Inflammasome activation in NADPH oxidase defective mononuclear phagocytes from patients with chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inherited disorder characterized by recurrent infections and deregulated inflammatory responses. CGD is caused by mutations in subunits of the NADPH oxidase, an enzyme that generates reactive oxygen species in phagocytes. To elucidate the contribution of the proinflammatory protease caspase-1 to aberrant inflammatory reactions in CGD, we analyzed cells isolated from patients with defects in the phagocyte oxidase subunits p22phox, p47phox or gp91phox. We report that mononuclear phagocytes from CGD patients activated caspase-1 and produced biologically active interleukin-1beta (IL-1beta) in response to danger signals. Notably, caspase-1 activation and IL-1beta secretion from CGD monocytes was elevated in asymptomatic patients and strongly increased in patients with noninfectious inflammatory conditions. Treatment with IL-1 receptor antagonist reduced IL-1 production in monocytes ex vivo and during medical therapy. Our results identify phagocyte oxidase defective monocytes as a source of elevated IL-1 and provide a potential therapeutic option to ameliorate inflammatory conditions associated with CGD.

Manipulation of indoleamine 2,3 dioxygenase; a novel therapeutic target for treatment of diseases

BACKGROUND

The discovery of indoleamine 2,3-dioxygenase (IDO) as a modulator for the maintenance of fetomaternal immuno-privileged state has been heralded as a significant step in further defining the role of IDO in immunobiology. IDO is an IFN-inducible, intracellular enzyme that catalyzes the initial and rate-limiting step in the degradation of the essential amino acid, tryptophan. It has been suggested that IDO has the capacity to regulate the immune system via two discrete mechanisms; firstly the deprivation of tryptophan, which is essential for T cell proliferation and via the cytotoxic effects of tryptophan metabolites on T(H)1 cell survival.

METHODS

The sources of information used to prepare the paper are published work on Pubmed/Medline. In this review, we examine the therapeutic role of modulating IDO activity a variety of disease states including tumour tolerance, chronic infection, transplant rejection, autoimmunity and asthma. We propose that IDO represents a novel therapeutic target for the treatment of these diseases. We also explore the diverse strategies which are being employed, either to augment or to inhibit IDO activity in order to modify various disease processes. The limitations associated with these strategies are also scrutinized.

Nox proteins in signal transduction

The NADPH oxidase (Nox) family of superoxide (O(2)(*-)) and hydrogen peroxide (H(2)O(2))-producing proteins has emerged as an important source of reactive oxygen species (ROS) in signal transduction. ROS produced by Nox proteins Nox1-5 and Duox1/2 are now recognized to play essential roles in the physiology of the brain, the immune system, the vasculature, and the digestive tract as well as in hormone synthesis. Nox-derived ROS have been implicated in regulation of cytoskeletal remodeling, gene expression, proliferation, differentiation, migration, and cell death. These processes are tightly controlled and reversible. In this review, we will discuss recent literature on Nox protein tissue distribution, subcellular localization, activation, and the resulting signal transduction mechanisms.

The mucosal firewalls against commensal intestinal microbes

Mammals coexist with an extremely dense microbiota in the lower intestine. Despite the constant challenge of small numbers of microbes penetrating the intestinal surface epithelium, it is very unusual for these organisms to cause disease. In this review article, we present the different mucosal firewalls that contain and allow mutualism with the intestinal microbiota.

Role of NADPH oxidase in formation and function of multinucleated giant cells

Macrophages play essential roles in a wide variety of physiological and pathological processes. One of the unique features of these phagocytic leukocytes is their ability to fuse, forming multinucleated giant cells. Multinucleated giant cells are important mediators of tissue remodeling and repair and are also responsible for removal or sequestration of foreign material, intracellular bacteria and non-phagocytosable pathogens, such as parasites and fungi. Depending on the tissue where fusion occurs and the inflammatory insult, multinucleated giant cells assume distinctly different phenotypes. Nevertheless, the ultimate outcome is the formation of large cells that can resorb bone tissue (osteoclasts) or foreign material and pathogens (giant cells) extracellularly. While progress has been made in recent years, the mechanisms and factors involved in macrophage fusion are still not fully understood. In addition to cytokines and a number of adhesion proteins and receptors, it is becoming increasingly clear that NADPH oxidase-generated reactive oxygen species (ROS) also play an important role in macrophage fusion. In this review, we provide an overview of macrophage multinucleation, with a specific focus on the role of NADPH oxidases and ROS in macrophage fusion and in the function of multinucleated giant cells. In addition, we provide an updated overview of the role of these cells in inflammation and various autoimmune diseases.