Model Of Chronic Granulomatous Disease Research Articles

Naked Antibody-Based Conditioning Targeting CD47 and CD117 Plus Janus Kinase Inhibition Enables Toxin-Free, Radiation-Free, and Chemotherapy-Free Fully Mismatched Allogeneic Hematopoietic Stem Cell Transplantation

INTRODUCTION: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for numerous malignant and non-malignant hematologic diseases. To enable engraftment of donor hematopoietic stem cells (HSCs), recipients undergo conditioning with chemotherapy and irradiation to make marrow space for incoming donor HSCs and suppress host immune responses that may lead to graft rejection. These cytotoxic conditioning regimens carry risks of severe toxicities which prevents many patients from accessing the lifesaving benefit of allo-HSCT. Previously, we developed fully ablative CD45- and cKit-targeted antibody-drug conjugates (ADC) which, when combined with Janus kinase 1/2 (JAK1/2) inhibitors, enabled fully mismatched allo-HSCT with full donor chimerism and minimal toxicity while providing durable antileukemia activity (Persaud et al (2022), ASH Abstract). However, even ADCs carry potential risks of acute and chronic toxicities that may preclude their common use as HSCT conditioning agents. Moreover, unlike malignant diseases, allo-HSCT for non-malignant diseases does not require the conditioning regimen to provide antitumor benefit and partial donor chimerism may be sufficient for cure, strongly favoring the use of less intense conditioning strategies with the fewest possible toxicities. We hypothesized that naked antibody-based conditioning strategies can achieve the therapeutic benefits of allo-HSCT for non-malignant hematologic diseases, obviating exposure to toxic ADC payloads. METHODS: We combined unconjugated antibodies targeting CD47 and cKit with JAK1/2 inhibition to perform minor histocompatibility antigen (miHA)-mismatched (129/Sv→B6-Ly5.1) and fully mismatched (BALB/c→B6) murine allo-HSCT. In some full mismatch HSCT experiments, recipients included B6-gp91phox -/- mice, which serve as a model of chronic granulomatous disease (CGD) due to their deficiency in a catalytic subunit of NADPH oxidase. Mice received 100 µg anti-CD47 (clone mIAP410; BioXcell) 8 days before HSCT (d-8) as a priming dose to reduce the severity of CD47 blockade-induced anemia. Next, mice received 500 µg anti-cKit (clone ACK2; BioLegend) on d-6 and daily 500 µg doses of anti-CD47 from d-6 through d-2. For JAK1/2 inhibition, mice received oral ruxolitinib (Incyte; 2 mg drug/g chow) starting d-3 or d-1 and continuing until d+28. On d0, recipients were transplanted with 20 x 10 6 whole bone marrow cells from 129/Sv (miHA) or BALB/c (fully mismatched) mice. Peripheral blood donor chimerism was followed monthly by flow cytometry for CD45.2 + (miHA) or H-2D d+ (fully mismatched) cells. Oxidative burst among granulocytes in B6-gp91phox -/- recipients was assessed by dihydrorhodamine 123 (DHR123) staining after phorbol 12-myristate 13-acetate (PMA) stimulation. RESULTS: CD47 and cKit antibodies plus ruxolitinib enabled multilineage engraftment in both miHA and fully mismatched allo-HSCT, including myeloid lineage donor chimerism of 95-99% (Figure 1A). As expected, CD47 blockade induced significant but transient morbidity from anemia during the peritransplant period; notably, a shorter duration of ruxolitinib treatment before HSCT (starting d-1 instead of d-3) improved the tolerability of the regimen without impacting engraftment success. Allo-HSCT of B6-gp91phox -/- mice led to near complete replacement of host granulocytes in peripheral blood with donor granulocytes, whose DHR123 positivity upon PMA stimulation indicated an intact oxidative burst capacity (Figure 1B). CONCLUSIONS: Combination of antibodies targeting CD47 and cKit with JAK1/2 inhibition provides a novel conditioning strategy for allo-HSCT in mouse models, achieving high-level, stable multilineage engraftment without radiation, chemotherapy, or exposure to toxic ADC payloads. The near complete donor chimerism among granulocytes made it particularly well suited to correcting phagocyte oxidase function in the gp91phox -/- model of CGD. Future studies seek to 1) mitigate the peritransplant anemia caused by CD47 blockade using Fc-silenced anti-CD47 reagents, 2) determine the proportions of donor- versus recipient-derived myeloid cells in non-hematopoietic tissues of allo-HSCT recipients, and 3) use murine infection models to evaluate the impact of allo-HSCT on host defense in transplanted B6-gp91phox -/- recipients.

Bi-fluorescent Staphylococcus aureus infection enables single-cell analysis of intracellular killing in vivo.

Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD.

Treatment with Polyethylene Glycol–Conjugated Fungal d-Amino Acid Oxidase Reduces Lung Inflammation in a Mouse Model of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a primary immunodeficiency wherein phagocytes are unable to produce reactive oxygen species (ROS) owing to a defect in the nicotinamide adenine dinucleotide phosphate oxidase (NADPH) complex. Patients with CGD experience bacterial and fungal infections and excessive inflammatory disorders. Bone marrow transplantation and gene therapy are theoretically curative; however, residual pathogenic components cause inflammation and/or organic damage in patients. Moreover, antibiotic treatments may not help in preventing excessive inflammation due to the residual presence of fungal cell wall β-glucan. Thus, better treatment strategies against CGD are urgently required. Polyethylene glycol–conjugated recombinant porcine d-amino acid oxidase (PEG-pDAO) supplies ROS to defective NADPH oxidase in neutrophils of patients with CGD, following which the neutrophils regain bactericidal activity in vitro. In this study, we employed an in vivo nonviable Candida albicans (nCA)–induced lung inflammation model of gp91-phox knockout CGD mice and supplied novel PEG conjugates of Fusarium spp. d-amino acid oxidase (PEG-fDAO), as it exhibits higher enzyme activity than PEG-pDAO. The body weight, lung weight, and lung pathology were evaluated using three experimental strategies with the in vivo lung inflammation model to test the efficacy of the ROS-generating enzyme replacement therapy with PEG-fDAO. The lung weight and pathological findings suggest the condition was ameliorated by administration PEG-fDAO, followed by intraperitoneal injection of d-phenylalanine or d-proline. Although a more precise protocol is essential, these data reveal the targeted delivery of PEG-fDAO to the nCA-induced inflammation site and show that PEG-fDAO can be used to treat inflammation in CGD in vivo.

Granuloma Formation in a Cyba-Deficient Model of Chronic Granulomatous Disease Is Associated with Myeloid Hyperplasia and the Exhaustion of B-Cell Lineage.

Haematopoiesis is a paradigm of cell differentiation because of the wide variety and overwhelming number of mature blood cells produced daily. Under stress conditions, the organism must adapt to a boosted demand for blood cells. Chronic granulomatous disease (CGD) is a genetic disease caused by inactivating mutations that affect the phagocyte oxidase. Besides a defective innate immune system, CGD patients suffer from recurrent hyper-inflammation episodes, circumstances upon which they must face emergency haematopoiesis. The targeting of Cybb and Ncf1 genes have produced CGD animal models that are a useful surrogate when studying the pathophysiology and treatment of this disease. Here, we show that Cyba−/− mice spontaneously develop granuloma and, therefore, constitute a CGD animal model to complement the existing Cybb−/− and Ncf1−/− models. More importantly, we have analysed haematopoiesis in granuloma-bearing Cyba−/− mice. These animals showed a significant loss of weight, developed remarkable splenomegaly, bone marrow myeloid hyperplasia, and signs of anaemia. Haematological analyses showed a sharped decrease of B-cells and a striking development of myeloid cells in all compartments. Collectively, our results show that granuloma inflammatory lesions dramatically change haematopoiesis homeostasis. Consequently, we suggest that besides their defective innate immunity, the alteration of haematopoiesis homeostasis upon granuloma may contribute to the dismal outcome of CGD.

A Shifted Composition of the Lung Microbiota Conditions the Antifungal Response of Immunodeficient Mice.

The microbiome, i.e., the communities of microbes that inhabit the surfaces exposed to the external environment, participates in the regulation of host physiology, including the immune response against pathogens. At the same time, the immune response shapes the microbiome to regulate its composition and function. How the crosstalk between the immune system and the microbiome regulates the response to fungal infection has remained relatively unexplored. We have previously shown that strict anaerobes protect from infection with the opportunistic fungus Aspergillus fumigatus by counteracting the expansion of pathogenic Proteobacteria. By resorting to immunodeficient mouse strains, we found that the lung microbiota could compensate for the lack of B and T lymphocytes in Rag1–/– mice by skewing the composition towards an increased abundance of protective anaerobes such as Clostridia and Bacteroidota. Conversely, NSG mice, with major defects in both the innate and adaptive immune response, showed an increased susceptibility to infection associated with a low abundance of strict anaerobes and the expansion of Proteobacteria. Further exploration in a murine model of chronic granulomatous disease, a primary form of immunodeficiency characterized by defective phagocyte NADPH oxidase, confirms the association of lung unbalance between anaerobes and Proteobacteria and the susceptibility to aspergillosis. Consistent changes in the lung levels of short-chain fatty acids between the different strains support the conclusion that the immune system and the microbiota are functionally intertwined during Aspergillus infection and determine the outcome of the infection.

Lactate Release By Bone Marrow Neutrophils Promotes Their Inflammatory Mobilization Via Endothelial GPR81 Signaling

Neutrophils are best known as glycolytic cells and an essential first host defense line of the innate immune system during inflammation. Activation of pro-inflammatory signaling by immune cells accelerates metabolic pathways, leading to increased lactate production. While lactate levels are the best clinical marker for sepsis diagnosis, the mechanisms underlying lactate production by bone marrow (BM) neutrophils and its role during inflammation remain poorly understood. Here, we report that LPS exposure in mice (mimicking bacterial inflammation) activated BM neutrophils leading to their mobilization to peripheral blood (PB) and recruitment to the liver. This happened concomitantly with an increase in BM neutrophil metabolism, reflected by high glucose uptake, high generation of reactive oxygen species (ROS) and increase in HIF-1α expression. Importantly, we identified that BM neutrophils highly express lactate dehydrogenase A (LDHA), an enzyme that converts pyruvate to lactate, as well as the lactate efflux transporter MCT4. On the other hand BM neutrophils express low levels of the lactate influx transporter MCT1 and the lactate receptor GPR81. In addition, we found that BM neutrophil depletion resulted in lower levels of BM derived lactate in mice exposed to LPS. Moreover, LPS administration up-regulated the expression of LDHA and MCT4 on BM neutrophils. Taken together, these results reveal that during acute LPS induced inflammation BM neutrophils produce and release high levels of lactate. Unexpectedly, we found that in vivo lactate treatment specifically induced rapid ROShigh neutrophil activation and mobilization from the BM to PB and liver in an NADPH oxidase/ROS dependent manner. Accordingly, reduced activated neutrophil levels in PB and liver were observed following inhibition of ROS production. Furthermore, in a genetic mouse model of Chronic Granulomatous Disease (CGD) due to NADPH oxidase inactivation, with reduced ROS generation, treatment with lactate partially reduced neutrophil mobilization from the BM. Our results demonstrate that NADPH oxidase/ROS signaling play a role in lactate-induced neutrophil mobilization. HIF-1α is a major regulator of energy metabolism and glycolysis pathway in immune cells (Reviewed by Weidemann and Johnson, Cell Death and Diff. 2008, and by O'Neill and Pearce, J. Exp. Med. 2015). Notably, our results show in myeloid specific HIF-1α-deficient mice exposed to LPS a reduction in the expression of LDHA and MCT4 on BM neutrophils compared to wild type mice, suggesting that HIF-1α is upstream of lactate. Accordingly, exogenous lactate administration restored neutrophil mobilization in myeloid HIF-1α-deficient mice implicating HIF-1α in lactate production and release by BM neutrophils and in their mobilization from the BM following acute inflammation.Further deciphering the mechanisms of lactate-induced neutrophil mobilization, we identified that BM endothelial cells (BMEC) highly express the lactate receptor GPR81. This GPCR was downregulated and internalized by lactate, as well as GPR81 agonist or LPS treatment. Interestingly, we found that lactate or GPR81 agonist reduced BMEC VE-Cadherin expression, leading to increased blood-BM vascular permeability as a possible cause for the enhanced neutrophil mobilization from the BM into the circulation. Lactate effects on BM neutrophils required functional GPR81 signaling since lactate injection together with a GPR81 antagonist, or to GPR81-deficient mice interfered with BM vascular permeability and reduced neutrophil mobilization from the BM. Moreover, in chimeras of GPR81-deficient BM reconstituted in wild type mice recipients we found that lactate induced-neutrophil mobilization is dependent on host BMEC GPR81 signaling rather than hematopoietic cell GPR81. This finding eludes to a role of endothelial GPR81 rather than to neutrophil GPR81 in lactate induced-neutrophil mobilization. In summary, our study links, for the first time, the metabolic by-product lactate secreted by BM neutrophils exposed to inflammatory conditions, to a novel GPR81 signaling axis on the BM endothelial cells which controls vascular permeability and thereby neutrophil mobilization. Our study highlights lactate as a potential target for attenuating blood neutrophilia and neutrophil injury associated with sepsis and other infectious conditions. DisclosuresNo relevant conflicts of interest to declare.

CRISPR gene-engineered CYBBko THP-1 cell lines highlight the crucial role of NADPH-induced reactive oxygen species for regulating inflammasome activation

Summary CRISPR-Cas9 engineered CYBBko THP-1 cell lines display an inflammatory profile with increased IL-1β, IL-6 and TNF-α secretion as consequence of NADPH-induced ROS deficiency. This phenotype is reminiscent of the one observed in phagocytes from CGD patients.

Antisense Inhibitors Retain Activity in Pulmonary Models of Burkholderia Infection.

The Burkholderia cepacia complex is a group of Gram-negative bacteria that are opportunistic pathogens in immunocompromised individuals, such as those with cystic fibrosis (CF) or chronic granulomatous disease (CGD). Burkholderia are intrinsically resistant to many antibiotics and the lack of antibiotic development necessitates novel therapeutics. Peptide-conjugated phosphorodiamidate morpholino oligomers are antisense molecules that inhibit bacterial mRNA translation. Targeting of PPMOs to the gene acpP, which is essential for membrane synthesis, lead to defects in the membrane and ultimately bactericidal activity. Exploration of additional PPMO sequences identified the ATG and Shine-Dalgarno sites as the most efficacious for targeting acpP. The CF lung is a complex microenvironment, but PPMO inhibition was still efficacious in an artificial model of CF sputum. PPMOs had low toxicity in human CF cells at doses that were antibacterial. PPMOs also reduced the bacterial burden in the lungs of immunocompromised CyBB mice, a model of CGD. Finally, the use of multiple PPMOs was efficacious in inhibiting the growth of both Burkholderia and Pseudomonas in an in vitro model of coinfection. Due to the intrinsic resistance of Burkholderia to traditional antibiotics, PPMOs represent a novel and viable approach to the treatment of Burkholderia infections.

AQP8 transports NOX2-generated H2O2 across the plasma membrane to promote signaling in B cells.

H2O2 acts as a second messenger in key signaling circuits, transiently modulating tyrosine phosphatases and kinases. We investigated its origin, membrane transport, and functional role during B cell activation and differentiation. Our data identified NADPH-oxidase 2 as the main source of H2O2 and aquaporin 8 as a transport facilitator across the plasma membrane. On aquaporin 8 silencing, inducible B lymphoma cells responded poorly to TLR and BCR stimulation. Their differentiation was severely impaired, as demonstrated by retarded onset of IgM polymerization, low amounts of IgM secretion, and prolonged BCR expression on the cell surface. A silencing-resistant aquaporin 8 rescued responsiveness, confirming that the import of H2O2 across the membrane is essential for B cell activation. The addition of exogenous catalase to primary B splenocytes severely impaired the tyrosine phosphorylation induced by BCR cross-linking, as did the absence of NOX2 in a murine model of chronic granulomatous disease. Importantly, re-expression of gp91phox through gene therapy restored the specific B cell signaling deficiency in NOX2-/- cells. Thus, efficient induction of B cell activation and differentiation requires intact H2O2 fluxes across the plasma membrane for signal amplification.

Strain Specific Phage Treatment for Staphylococcus aureus Infection Is Influenced by Host Immunity and Site of Infection.

The response to multi-drug resistant bacterial infections must be a global priority. While mounting resistance threatens to create what the World Health Organization has termed a “post-antibiotic era”, the recent discovery that antibiotic use may adversely impact the microbiome adds further urgency to the need for new developmental approaches for anti-pathogen treatments. Methicillin-resistant Staphylococcus aureus (MRSA), in particular, has declared itself a serious threat within the United States and abroad. A potential solution to the problem of antibiotic resistance may not entail looking to the future for completely novel treatments, but instead looking into our history of bacteriophage therapy. This study aimed to test the efficacy, safety, and commercial viability of the use of phages to treat Staphylococcus aureus infections using the commercially available phage SATA-8505. We found that SATA-8505 effectively controls S. aureus growth and reduces bacterial viability both in vitro and in a skin infection mouse model. However, this killing effect was not observed when phage was cultured in the presence of human whole blood. SATA-8505 did not induce inflammatory responses in peripheral blood mononuclear cultures. However, phage did induce IFN gamma production in primary human keratinocyte cultures and induced inflammatory responses in our mouse models, particularly in a mouse model of chronic granulomatous disease. Our findings support the potential efficacy of phage therapy, although regulatory and market factors may limit its wider investigation and use.

Olfm4 deletion enhances defense against Staphylococcus aureus in chronic granulomatous disease

Chronic granulomatous disease (CGD) patients have recurrent life-threatening bacterial and fungal infections. Olfactomedin 4 (OLFM4) is a neutrophil granule protein that negatively regulates host defense against bacterial infection. The goal of this study was to evaluate the impact of Olfm4 deletion on host defense against Staphylococcus aureus and Aspergillus fumigatus in a murine X-linked gp91phox-deficiency CGD model. We found that intracellular killing and in vivo clearance of S. aureus, as well as resistance to S. aureus sepsis, were significantly increased in gp91phox and Olfm4 double-deficient mice compared with CGD mice. The activities of cathepsin C and its downstream proteases (neutrophil elastase and cathepsin G) and serum levels of IL-1β, IL-6, IL-12p40, CXCL2, G-CSF, and GM-CSF in Olfm4-deficient as well as gp91phox and Olfm4 double-deficient mice were significantly higher than those in WT and CGD mice after challenge with S. aureus. We did not observe enhanced defense against A. fumigatus in Olfm4-deficient mice using a lung infection model. These results show that Olfm4 deletion can successfully enhance immune defense against S. aureus, but not A. fumigatus, in CGD mice. These data suggest that OLFM4 may be an important target in CGD patients for the augmentation of host defense against bacterial infection.

Deletion of OLFM4 Rescues Defective Host Defense Against Staphylococcus Aureus, but Not Aspergillus Fumigatus in Murine X-Linked Chronic Granulomatous Disease

AbstractAbstract 3276 Introduction:Chronic granulomatous disease (CGD) patients have recurrent life-threating bacterial and fungal infections due to the mutation of one of four subunits of the respiratory burst oxidase (NADPH-oxidase). Currently, the overall fatality rate in CGD patients remains high, making it necessary to better understand the basic biological processes governing host defense against bacteria and fungi in CGD. Olfactomedin 4 (OLFM4) is a neutrophil granule protein, which has been recently identified as a negative regulator of host innate immunity against bacteria infection in mice through modulation of neutrophil protease activity. The goal of this study was to evaluate the impact of OLFM4 deletion on host innate immunity against Staphylococcus aureus and Aspergillus fumigatus, two major pathogens encountered in CGD patients, in a murine X-linked CGD model. Results:We created gp91phox-and OLFM4-double deficient mice and investigated the mice defense against S. aureus and A. fumigatus infection. We found that neutrophil intracellular killing and in vivo clearance of S. aureus have been significantly increased in gp91phox- and OLFM4-double deficiency mice compared with CGD mice. The mice survival to S. aureus sepsis in gp91phox- and OLFM4-double deficiency mice has also been significantly prolonged compared with CGD mice. Our study has shown that the CGD mice immune deficiency against S. aureus has been totally corrected by additional loss of OLFM4 gene. To explore the mechanism that OLFM4 deletion rescued the bactericidal activities of CGD neutrophils, we analyzed cathepsin C and its downstream protease (neutrophil elastase and cathepsin G) activities in the mice neutrophils. Cathepsin C activities in OLFM4 deficient as well as double deficient mice neutrophils were significantly higher than those in WT mouse neutrophils. Cathepsin C activities in the neutrophils of CGD were similar to those in WT mice. Accordingly, the elastase and cathepsin G activities in the neutrophils of OLFM4 deficient and double deficient mice were also substantially higher than those in WT mice as well as CGD mice. However, we have not observed enhanced innate immunity against A. fumigatus in OLFM4 deficiency mice compared with wild-type mice using a lung infection model. The lung histopathology showed similar inflammation and fungal burden in the OLFM4 deficiency mice compared with wild-type mice. Correspondingly, mice survival to severe A. fumigatus infection did not show significant difference in gp91phox- and OLFM4-double deficiency mice compared with CGD mice, suggesting that OLFM4 may not play a role in mice host defense against A. fumigatus. Conclusion:1. The damaged neutrophil bacterial killing and host innate immunity against S. aureus in CGD mice due to oxidative mechanism deficiency could be successfully rescued by deletion of OLFM4. 2. These results showed that the granule protease activities in CGD neutrophils could be substantially enhanced above the level in normal neutrophils by deletion of OLFM4, suggesting that the increased of serine proteinase activities due to OLFM4 deletion is NADPH-independent. 3. OLFM4 may not play a role in mice host defense against pulmonary A. fumigatus infection. 4. OLFM4 might prove to be an important target in CGD patients to augment host defense against bacterial infection. Disclosures:No relevant conflicts of interest to declare.

Control of the chronic inflammatory response in a murine model of chronic granulomatous disease (54.8)

Abstract Chronic granulomatous disease (CGD) is a primary innate immunodeficiency associated with a defective phagocyte NADPH oxidase complex and thus increased susceptibility to recurrent bacterial and fungal infections. Although antimicrobials have proven useful in resolving primary infection, CGD patients face complications thought to stem from an unresolved hyper-inflammatory state. Using a murine model of CGD we found that a sterile inflammatory insult induces a systemic and long-lived chronic inflammatory response not seen in wild type controls. This persistent inflammatory response is characterized by an increased and sustained expansion of myeloid cells, including Gr1+Ly6G+ cells actively producing the pro-inflammatory IFNγ cytokine and a Gr1+Ly6G- myeloid-derived suppressor cell (MDSC) population. Interestingly, although the expansion of a functional MDSC population would suggest a viable mechanism to control the persistent hyper-inflammatory response, we found that the Gr1+Ly6G+ subpopulation antagonizes MDSC function which significantly affects control of adaptive T cell responses, including responses to inhaled antigen in the lung, a frequently affected organ in CGD patients. Understanding CGD immune dysregulation beyond the primary innate immunodeficiency allows for the development of targeted therapies to potentially prevent inflammatory complications in CGD patients and possibly other patients at risk of complications due to chronic inflammation.

279. Derivation and Functional Analysis of Patient Specific Induced Pluripotent Stem Cells as an In Vitro Model of Chronic Granulomatous Disease

279. Derivation and Functional Analysis of Patient Specific Induced Pluripotent Stem Cells as an In Vitro Model of Chronic Granulomatous Disease

CD4+ T cell vaccination overcomes defective cross-presentation of fungal antigens in a mouse model of chronic granulomatous disease

Aspergillus fumigatus is a model fungal pathogen and a common cause of infection in individuals with the primary immunodeficiency chronic granulomatous disease (CGD). Although primarily considered a deficiency of innate immunity, CGD is also linked to dysfunctional T cell reactivity. Both CD4(+) and CD8(+) T cells mediate vaccine-induced protection from experimental aspergillosis, but the molecular mechanisms leading to the generation of protective immunity and whether these mechanisms are dysregulated in individuals with CGD have not been determined. Here, we show that activation of either T cell subset in a mouse model of CGD is contingent upon the nature of the fungal vaccine, the involvement of distinct innate receptor signaling pathways, and the mode of antigen routing and presentation in DCs. Aspergillus conidia activated CD8(+) T cells upon sorting to the Rab14(+) endosomal compartment required for alternative MHC class I presentation. Cross-priming of CD8(+) T cells failed to occur in mice with CGD due to defective DC endosomal alkalinization and autophagy. However, long-lasting antifungal protection and disease control were successfully achieved upon vaccination with purified fungal antigens that activated CD4(+) T cells through the endosome/lysosome pathway. Our study thus indicates that distinct intracellular pathways are exploited for the priming of CD4(+) and CD8(+) T cells to A. fumigatus and suggests that CD4(+) T cell vaccination may be able to overcome defective antifungal CD8(+) T cell memory in individuals with CGD.

Derivation and functional analysis of patient-specific induced pluripotent stem cells as an in vitro model of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is an inherited disorder of phagocytes in which NADPH oxidase is defective in generating reactive oxygen species. In this study, we reprogrammed three normal unrelated patient's fibroblasts (p47phox and gp91phox) to pluripotency by lentiviral transduction with defined pluripotency factors. These induced pluripotent stem cells (iPSC) share the morphological features of human embryonic stem cells, express the key pluripotency factors, and possess high telomerase activity. Furthermore, all the iPSC lines formed embryoid bodies in vitro containing cells originating from all three germ layers and were capable of teratoma formation in vivo. They were isogenic with the original patient fibroblasts, exhibited normal karyotype, and retained the p47phox or gp91phox mutations found in the patient fibroblasts. We further demonstrated that these iPSC could be differentiated into monocytes and macrophages with a similar cytokine profile to blood-derived macrophages under resting conditions. Most importantly, CGD-patient-specific iPSC-derived macrophages showed normal phagocytic properties but lacked reactive oxygen species production, which correlates with clinical diagnosis of CGD in the patients. Together these results suggest that CGD-patient-specific iPSC lines represent an important tool for modeling CGD disease phenotypes, screening candidate drugs, and the development of gene therapy. Stem Cells 2012; 30:599–611

Chronic granulomatous disease

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency due to an abnormal function of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase; NADPH oxidase is a key enzyme for the cellular "respiratory burst", the cellular process that converts molecular oxygen to the oxygen free-radical superoxide. As a consequence of NADPH oxidase defect, CGD patients suffer from recurrent life-threatening infections and from exceeding inflammatory responses leading to granulomas. This article analyzes clinical aspects of CGD. Furthermore, using the CGD model, we focused on the future perspective to reduce atherosclerosis and its complications.

Role of p47phox in Antigen-Presenting Cell-Mediated Regulation of Humoral Immunity in Mice

Microbial-induced inflammation is important for eliciting humoral immunity. Genetic defects of NADPH oxidase 2-based proteins interrupt phagocyte superoxide generation and are the basis for the human immunodeficiency chronic granulomatous disease (CGD). Hyperinflammation is also a significant clinical manifestation of CGD. Herein, we evaluated humoral immunity in the phagocyte oxidase p47(phox)-deficient model of CGD and found that UV-inactivated Streptococcus pneumoniae and Listeria monocytogenes (Lm) elicited higher specific antibody (Ab) titers in p47(phox-/-) mice than wild-type (WT) mice. Both organisms elicited robust and distinct antigen-presenting cell maturation phenotypes, including IL-12 hypersecretion, and higher major histocompatibility complex II and costimulatory protein expression in Lm-stimulated p47(phox-/-) dendritic cells (DCs) relative to WT DCs. Furthermore, p47(phox-/-) DCs pulsed with Lm and adoptively transferred into naïve WT mice elicited Ab titers, whereas Lm-pulsed WT DCs did not elicit these titers. The observed robust p47(phox-/-) mouse humoral response was recapitulated with live Lm and sustained in vivo in p47(phox-/-) mice. Notably, anti-serum samples from p47(phox-/-) mice that survived secondary Lm infection were protective in WT and p47(phox-/-) mice that were rechallenged with secondary lethal Lm infection. These findings demonstrate a novel benefit of NADPH oxidase 2 deficiency (ie, dependent inflammation in antigen-presenting cell-mediated humoral immunity) and that anti-Lm Ab can be protective in an immunodeficient CGD host.

Adenosine A2A receptor activation inhibits T cell activity in a murine model of chronic granulomatous disease (87.3)

Abstract Chronic granulomatous disease (CGD) is caused by defects in the NADPH oxidase system, and is characterized by an increased susceptibility to recurrent, severe bacterial and fungal infections. Early diagnosis and aggressive treatment can be effective at combating life threatening infections, but other significant complications of CGD, such as non-infectious hyperinflammatory manifestations, result in a high associated morbidity. Recent studies suggest that the hyperinflammation observed in CGD (gp91phox deficient) mice may be due in part to dysregulated T cell activity. We have broadly characterized the phenotypes of T lymphocytes collected from p91phox deficient mice and our data indicate that although the basal activation states of T cells collected from WT and CGD mice are similar, upon activation through the T cell receptor, CGD T cells produce higher levels of the pro-inflammatory cytokines IFN-γ and IL-2 and express elevated levels of the cell surface activation markers CD25, CD69 and CD40L as compared to WT T cells. This hyper-activation of CGD T cells is effectively modulated by treatment with the selective adenosine A2A receptor agonist CGS21680, which reduces the levels of IFN-γ and IL-2 by approximately 90% and down regulates CD25, CD69 and CD40L expression by approximately 50%. These data suggest that the adenosine A2A receptor is a potential pharmacological target for the treatment of the hyperinflammatory complications observed in CGD patients.

Impaired host defence against Mycobacterium avium in mice with chronic granulomatous disease

Patients with chronic granulomatous disease (CGD), an inherited disorder of phagocytic cells, often contract recurrent life-threatening bacterial and fungal infections. CGD is considered to arise from a functional defect of the O(2)-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in phagocytes. To determine whether or not NADPH oxidase is crucial to the host defence against Mycobacterium avium, we investigated the response against M. avium using CGD model mice (gp91-phox(-)) of C57BL/6 strain. A tracheal injection of 1 x 10(7) colony-forming units (CFU)/head of M. avium strain FN into the CGD mice resulted in a pulmonary infection, while also increasing the mortality rate. In contrast, normal C57BL/6 mice injected with same dose of the organisms did not develop severe pulmonary infection and were able to survive through 2 months of observation. The macrophages obtained from the CGD mice were observed to have a higher burden of the bacterial growth than macrophages from normal C57BL/6 mice. These results suggest that the defect of the NADPH oxidase function impairs the host defence against M. avium infection.