La dégénérescence maculaire liée à l'âge (DMLA) est la cause la plus fréquente de déficience visuelle centrale irréversible chez les personnes de plus de 50 ans dans les pays industrialisés, avec des impacts sociétaux et financiers majeurs. La DMLA est une maladie à multiples facettes provoquée par des interactions entre les facteurs de risque et les antécédents génétiques et l'inflammation joue un rôle important. Les effets pro-inflammatoires provoquent une perturbation de l'environnement sousrétinien physiologiquement immunosuppresseur. L'accumulation de phagocytes mononucléaires (PM) dans l'espace sous-rétinien qui s'ensuit est au coeur de l'étiologie des formes atrophiques et humides de la DMLA. Après l’usage de tabac, l'obésité est l'un des facteurs de risque modifiables les plus importants. Nous avons démontré que les régimes riches en graisses exacerbent la néovascularisation choroïdienne (NVC) en modifiant le microbiote intestinal. La dysbiose intestinale entraîne une perméabilité intestinale accrue, une inflammation chronique de bas grade, une augmentation des PM sur le site de l'angiogenèse pathologique dans l'oeil et exacerbe finalement la NVC. La modification du microbiote peut réduire l'inflammation et atténuer la NVC et peut ainsi fournir des traitements peu intrusifs et rentables pour prévenir ou retarder la DMLA exsudative. Une autre option thérapeutique qui pourrait réduire la NVC par modulation inflammatoire consiste à piéger localement les ligands de NRP1 avec un piège dérivé de NRP1. Les ligands de NRP1 sont élevés dans le vitré des patients atteints de DMLA. Nous avons constaté que les PM exprimant NRP1 favorisaient la NVC en atténuant la production de facteurs inflammatoires et en favorisant l'activation alternative, donnant aux PM un caractère pro-angiogénique. Les PM moins inflammatoires et plus de type M2 qui sont enrichis avec l'âge et exacerbent la NVC peuvent être modulés et devenir moins nuisibles en empêchant l'activation de NRP1. Cette thèse explore deux angles dans lesquels la régulation de l'inflammation peut influencer la formation de NVC et jette les bases du développement futur de nouveaux traitements préventifs primaires et secondaires efficaces dans le contexte de la DMLA. / Age related macular degeneration (AMD) is the most common cause of irreversible central vision impairment in people over 50 in industrialized countries, with major societal and financial impacts. AMD is a multifaceted disease provoked by interactions among environmental risk factors and genetic backgrounds in which inflammation plays an important role. Proinflammatory effects cause a disruption of the physiologically immunosuppressive subretinal environment. The ensuing accumulation of mononuclear phagocytes in the subretinal space is central to the etiology of both atrophic and wet forms of AMD. After smoking, obesity is one of the most important modifiable risk factors. We demonstrate that high-fat diets exacerbate choroidal neovascularisation (CNV) by altering gut microbiota. Gut dysbiosis leads to heightened intestinal permeability and chronic low-grade inflammation, increases recruitment of microglia and macrophages to the site of pathological angiogenesis in the eye and ultimately exacerbates CNV. Modifying microbiota can reduce systemic and local choroidal inflammation and attenuate pathological neovascularization and may thus provide minimally intrusive and cost-effective paradigms to prevent or delay exudative AMD. Another therapeutic option that could reduce CNV through inflammatory modulation is locally trapping ligands of NRP1 with a NRP1-derived trap. Ligands for NRP1 are elevated in the vitreous of patients with AMD at times of active CNV. We found that NRP1-expressing MPs promote CNV by mitigating production of inflammatory factors and promoting alternative activation, giving the MPs a pro-angiogenic character. The less inflammatory and more M2-like MPs that are enriched with age and exacerbate CNV can be rendered less detrimental by hindering NRP1 activation. This thesis explores two angles wherein regulation of inflammation can influence the formation of CNV and lays the groundwork for future development of novel effective primary and secondary preventive treatments for AMD.

A Doença Granulomatosa Crônica é uma imunodeficiência grave e rara, na qual os quadros infecciosos por bactérias e fungos, ocorrem predominantemente nas barreiras naturais do organismo. O defeito reside em mutações em um dos componentes do sistema NADPH oxidase. O dHPLC mostrou-se mais sensível que o SSCP, sendo eficaz na detecção de alterações em 100% dos casos. Identificamos sete mutações diferentes no gene CYBB, sendo quatro delas inéditas. São elas R226X; R290X; e C537R. Dentre as mutações inéditas identificamos: T302fsX46; c.141 +5 G> T; C185R; e H222L. Identificamos a mutação V25fsX51 no gene NCF1 em duas pacientes. Estabelecemos uma correlação entre genótipo e fenótipo clínico baseado em manifestações clínicas relevantes na DGC, nos fornecendo dados importantes de cada manifestação clínica e um índice de gravidade clínica (IGC) para cada tipo de mutação. Os resultados contribuem para a construção de estratégias que permitam a identificação dos defeitos genético-moleculares relacionados à DGC. / Chronic granulomatous disease is a primary immunodeficiency characterized by recurrent and severe infections, affecting the body barriers. In these patients, phagocytes present a failure in the respiratory burst caused by a deficiency of the NADPH oxidase system, and a microbicidal defect. Mutations affecting one of the components of the NADPH oxidase system. The dHPLC proved to be more sensitive to the SSCP, being effective in detecting changes in 100% of cases. We found seven different mutations, four of which are original. Are they R226X; R290X; and C537R. Among the unpublished mutations identified: T302fsX46; c. 141 + 5 G > T; C185R; and H222L. We identify the gene mutation V25fsX51 NCF1 in two patients. We have established a correlation between genotype and phenotype clinical relevant clinical manifestations based on DGC in providing important data from each clinical and clinical severity index (CSI) for each type of mutation. The results contribute to the construction of strategies enabling the identification of molecular genetic defects related to CGD.

A Doença Granulomatosa Crônica é uma imunodeficiência grave e rara, na qual os quadros infecciosos por bactérias e fungos, ocorrem predominantemente nas barreiras naturais do organismo. O defeito reside em mutações em um dos componentes do sistema NADPH oxidase. O dHPLC mostrou-se mais sensível que o SSCP, sendo eficaz na detecção de alterações em 100% dos casos. Identificamos sete mutações diferentes no gene CYBB, sendo quatro delas inéditas. São elas R226X; R290X; e C537R. Dentre as mutações inéditas identificamos: T302fsX46; c.141 +5 G> T; C185R; e H222L. Identificamos a mutação V25fsX51 no gene NCF1 em duas pacientes. Estabelecemos uma correlação entre genótipo e fenótipo clínico baseado em manifestações clínicas relevantes na DGC, nos fornecendo dados importantes de cada manifestação clínica e um índice de gravidade clínica (IGC) para cada tipo de mutação. Os resultados contribuem para a construção de estratégias que permitam a identificação dos defeitos genético-moleculares relacionados à DGC. / Chronic granulomatous disease is a primary immunodeficiency characterized by recurrent and severe infections, affecting the body barriers. In these patients, phagocytes present a failure in the respiratory burst caused by a deficiency of the NADPH oxidase system, and a microbicidal defect. Mutations affecting one of the components of the NADPH oxidase system. The dHPLC proved to be more sensitive to the SSCP, being effective in detecting changes in 100% of cases. We found seven different mutations, four of which are original. Are they R226X; R290X; and C537R. Among the unpublished mutations identified: T302fsX46; c. 141 + 5 G > T; C185R; and H222L. We identify the gene mutation V25fsX51 NCF1 in two patients. We have established a correlation between genotype and phenotype clinical relevant clinical manifestations based on DGC in providing important data from each clinical and clinical severity index (CSI) for each type of mutation. The results contribute to the construction of strategies enabling the identification of molecular genetic defects related to CGD.

The Gram-negative aerobic coccobacillus Bordetella pertussis is one of the few exclusively human pathogens and the main causative agent of the respiratory infectious disease called pertussis, or whooping cough. Despite global vaccination programs, pertussis remains an important public-health burden and still accounts for over 100,000 infant deaths and over a dozen of millions of whooping cough cases every year. Substantial effort is devoted to studies on the mechanisms of action of virulence factors of B. pertussis, but the biology of interactions of B. pertussis with its human host remains largely underexplored. Evolution, genetics and adaptation of B. pertussis to the complex environment of human nasopharynx and the mechanisms enabling B. pertussis to overcome host innate and adaptive mucosal immune defenses, remain poorly understood. In such situations, unbiased exploratory omics approaches represent valuable tools for uncovering of unknown aspects of host-pathogen interactions and open the path to detailed analysis of virulence-underlying processes by mechanistic studies. In this thesis, I am presenting the results of three omics projects on B. pertussis biology that involved high-throughput proteomics. In the inital phosphoprotemics project, we analyzed the kinase signaling pathways hijacked...

Le CD36 est un récepteur éboueur de classe B exprimé par plusieurs types cellulaires dont les macrophages et les cellules endothéliales de la microvasculature. Le CD36 présente une haute affinité de liaison pour les ligands lipidiques tels que les lipoprotéines oxydées de basse densité (LDLox). De part sa capacité à internaliser les LDLox au niveau des macrophages et de son implication dans la formation des cellules spumeuses, le CD36 joue un rôle critique dans le développement des lésions athérosclérotiques. Nous avons testé l'hypothèse selon laquelle le EP 80317, un ligand synthétique sélectif du CD36, exerce des effets anti-athérosclérotiques chez les souris déficientes en apolipoprotéine E. Un traitement prolongé (12 semaines) avec le EP 80317 réduit fortement (de 51%) la surface des lésions athérosclérotiques par comparaison aux souris témoins. L'effet anti-athérosclérotique est associé à une diminution des taux de cholestérol plasmatique, à une réduction de l’internalisation des LDLox au niveau des macrophages et à une augmentation de l’expression des protéines impliquées dans le transport inverse du cholestérol. De plus, un traitement par le EP 80317 est également associé une diminution de l’expression aortique et plasmatique de protéines pro-inflammatoires. Nos études ont aussi montré un rôle pour le CD36 dans le recrutement des phagocytes mononucléés au niveau des lésions athérosclérotiques, tel que démontré par une réduction de l’accumulation des phagocytes mononucléés radiomarqués CD36–/– par rapport aux cellules CD36+/+. À l’échelle moléculaire, nous avons montré que les phospholipides oxydés induisent la phosphorylation de la kinase Pyk2 des podosomes des monocytes/macrophages de manière dépendante de l’expression du CD36 et de Src. Cette phosphorylation est atténuée par un traitement par le EP80317. Nos résultats appuient le rôle important du CD36 dans l’athérosclérose et suggèrent que les ligands synthétiques qui modulent la fonction du CD36 représentent potentiellement une nouvelle classe d'agents anti-athérosclérotiques. Le CD36 exprimé par les cellules endothéliales de la microvasculature est un récepteur de l’hétérodimère protéique S100A8/A9. Ces protéines s’associent à l’acide arachidonique intracellulaire (AA) des neutrophiles polymorphonucléaires (PMN) et le complexe S100A8/A9/AA peut être sécrété par les PMN activés au contact de l’endothélium. Nous avons vérifié l’hypothèse selon laquelle le CD36 exprimé par la microvasculature est impliqué dans le métabolisme transcellulaire de l’AA par la liaison du complexe S100A8/A9/AA et la réponse inflammatoire. Chez deux modèles murins d'inflammation aiguë (ischémie/reperfusion des membres inférieurs et poche d’air dorsale), nous avons observé que la réponse inflammatoire, notamment l’accumulation des PMN au niveau des sites inflammatoires, est diminuée en moyenne de 63% chez les souris CD36-/-. De même, un traitement par le EP 80317 ou par les anticorps anti-S100A8/A9 diminue chacun de 60% en moyenne l’extravasation des PMN vers les tissus inflammatoires. L’administration simultanée des deux traitements n’a aucun effet supplémentaire, et ces traitements n’exercent aucun effet chez les souris CD36-/-. Nos résultats appuient le rôle du récepteur CD36 de la microvasculature dans la régulation de la réponse inflammatoire. L’utilisation des ligands synthétiques du CD36 pourrait représenter une nouvelle avenue thérapeutique dans le traitement des réponses inflammatoires aiguës. / CD36 is a class B scavenger receptor expressed by multiple cell types such as macrophages and microvascular endothelial cells. CD36 shows a high affinity binding towards lipid-based ligands such as oxidized low-density lipoproteins (oxLDL). Macrophage CD36 has been shown to play a critical role in the development of atherosclerotic lesions by its ability to internalize oxLDL and to lead to foam cell formation. We tested the hypothesis that EP 80317, a selective CD36 ligand, exerts anti-atherosclerotic effects in apolipoprotein E-deficient (apoE–/–) mice fed on atherogenic diet. Long term treatment (12 weeks) with EP 80317 results in a striking reduction (51%) of lesion areas in EP 80317-treated apoE–/– mice. This effect was associated with a decrease in plasma cholesterol, a reduced oxLDL internalization within macrophages and an up-regulation of proteins involved in cholesterol efflux. Additionally, treatment with EP 80317 was associated with a reduced expression of vascular and plasma pro-inflammatory proteins. Our studies also showed a role of CD36 in modulating the recruitment of mononuclear phagocytes to the arterial wall, as shown by a reduced migration of radiolabeled CD36-/- macrophages into atherosclerotic lesions compared to CD36+/+ cells. At the molecular level, our studies showed that oxidized phospholipids induced the phosphorylation of the adhesion kinase Pyk2 in monocytes/macrophages, in a CD36- and Src-dependent manner. The Pyk2 phosphorylation is attenuated by treatment with EP80317. Our results strongly support the role of CD36 in atherosclerosis development and suggest that synthetic ligands featuring modulatory effect on CD36 function may represent a novel class of anti-atherosclerotic agents. CD36 expressed by microvascular endothelial cells is a receptor for the heterodimer S100A8/A9. These proteins bind intracellular arachidonic acid (AA) within polymorphonuclear neutrophils (PMN) and the complex S100A8/A9-AA may be secreted at sites of inflammation where it exerts chemotactic activities. We aimed to delineate the role of microvascular CD36, as a receptor for the S100A8/A9, in the AA transcellular metabolism and the regulation of the associated PMN trafficking to inflammatory sites. In two mouse models of acute inflammation (hind limb ischemia/reperfusion and dorsal air pouch), CD36 regulated trafficking of PMN to inflammatory sites, as shown by a mean of 63% reduction of PMN accumulation in CD36-/- mice. Treatment with EP 80317 or with S100A8/A9 antibodies reduced, each by ~ 60%, the recruitment of PMN to inflammatory sites. The combined administration of anti-S100A8/A9 and EP 80317 did not exert any additional inhibitory effect and neither treatment featured a modulatory effect in CD36-/- mice. Our results strongly support a role for microvascular CD36 in regulating PMN trafficking to inflammatory sites. Targeting CD36 might represent a novel therapeutic avenue for the treatment of acute inflammatory responses.

Dentre pacientes com imunodeficiências primárias, existem aqueles com defeitos de fagócitos e outros componentes da imunidade inata. A doença granulomatosa crônica (DGC) é uma imunodeficiência primária (IDP) causada por mutações em um dos componentes protéicos, gp91-phox, p22-phox, p47-phox, p67-phox e p40-phox, da nicotinamida adenina dinucleotídeo fosfato (NADPH) dos fagócitos. Pacientes com DGC apresentam maior susceptibilidade a infecções, assim como hiperinflamação e reação adversa à vacinas como à do Bacilo Calmette-Guérin (BCG), como consequência da atividade microbicida defeituosa dos fagócitos. Por outro lado, a susceptibilidade mendeliana a micobactérias (MSMD) é uma condição que predispõe os pacientes a infecções pelo gênero Mycobacterium sp, levando a infecções graves e por vezes à morte. O objetivo deste trabalho foi realizar o diagnóstico clínico e a análise genético-molecular de pacientes brasileiros com DGC e MSMD. A explosão respiratória de granulócitos foi avaliada pelo ensaio de dihidrorodamina (DHR). A dosagem de citocinas do eixo IL-12/IFN-&#947 foi realizada mediante o ensaio de ELISA após estimulo com lisado de micobactérias (LM), proteína purifica (PPD) e BCG. O DNA genômico dos pacientes foi extraído, amplificado e sequenciado pelo método de Sanger e seqüenciamento completo de exoma. Durante o período de 2014-2018, 181 pacientes com histórico clínico sugestivo de DGC e 75 pacientes com diagnóstico sugestivo de MSMD foram encaminhados ao nosso laboratório. Após avaliação clínica e bioquímica dos pacientes, 23 deles foram diagnosticadas com DGC e 16 com MSMD. A análise genético-molecular permitiu identificar mutações em 14 pacientes com DGC, nove deles com DGC ligada ao cromossomo X (DGC-X) e 5 com DGC autossômica recessiva (DGC-AR). Identificamos mutações em 5 pacientes com MSMD, sendo três delas no receptor de IL-12 e duas no receptor da IL-17. / Among patients with primary immunodeficiencies, there are those with defects in phagocytes and other components of the innate immunity. Chronic granulomatous disease (CGD) is a primary immunodeficiency (PID) caused by mutations in one of the protein components, gp91-phox, p22-phox, p47-phox, p67-phox and p40-phox of the Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase of phagocytes. Patients with CDG are susceptible to infections, as well as hyperinflammation and adverse reactions to vaccines such as Bacilo Calmette-Guérin (BCG) as a consequence of defective phagocytes microbicidal activity. On the other hand, Mendelian susceptibility to mycobacterial diseases (MSMD) is a condition that predisposes patients to infections by the genus Mycobacterium sp , leading to serious infections and sometimes death. The main goal of this study was to perform the clinical diagnosis and genetic-molecular analysis of Brazilian patients with CDG and MSMD. The respiratory burst of granulocytes was evaluated by the dihydrorhodamine (DHR) assay. Cytokine dosing of IL-12 / IFN-&#947 axis was performed by the ELISA assay after stimulation with mycobacterium lysate (LM), purified protein (PPD) and BCG. Patients genomic DNA was extracted, amplified and sequenced by the Sanger method and whole exome sequencing. During the period of 2014 to 2018, 181 patients with a clinical history suggestive of CDG and 75 patients with a diagnosis suggestive of MSMD were referred to our laboratory. After clinical and biochemical evaluation, 23 of them were diagnosed with CDG and 16 with MSMD. Genetic-molecular analysis allowed the identification of mutations in 14 patients with CDG, of those 9 had X-linked DGC (X-CGD) and 5 had autosomal recessive CGD (AR-CGD). Mutations were identified in 5 MSMD patients, three in the IL-12 receptor and two in the IL-17 receptor.

No description available.

Anti-microbial proteins (AMP) are the key effector arm of the innate immune system. The prevalence of AMP in single-celled eukaryotes to humans shows its importance during the course of evolution. The first report for the role of the anti-microbial peptide in clearing infection was given by Alexander Fleming in 1990’s through the discovery of Penicillin and Lysozyme. The search for antimicrobial agents in human granulocytes was begun by Ehrlich in 1870’s but the first successful isolation of an antimicrobial agent from rabbit neutrophils was done by Zeya and Spitznagel in 1969. Later work by Peter Elshbach and his group on AMPs in rabbit neutrophils brought to light an AMP that can increase the permeability of the bacterial membrane. This AMP named as Bactericidal/permeability-increasing protein (BPI) was further isolated from human neutrophils. Since then many studies have been carried out to understand the mode of action of BPI, which culminated in understanding the new functional activity of this protein viz opsonisation, LPS neutralization and anti-angiogenic function. Knowing to the role of BPI as an anti-inflammatory agent, multiple studies have tried to use BPI for treating endotoxic shock. Dysregulation of BPI expression is associated with various inflammatory diseases like Crohn’s Disease (CD), Ulcerative colitis (UC) and Infectious enteritis’s. Mutations in BPI are also linked to susceptibility to various infections. Even though there are several studies focusing on the functional aspects of BPI, the regulation of BPI expression is poorly understood. Knowing the clinical importance of dysregulation of BPI, it is vital to understand the regulation of BPI expression during the course of bacterial infection. The Thesis is divided into four chapters. As the main aim of this study is to understand the regulation of BPI expression, in Chapter 1 we introduce the known facts about the protein. A brief overview of the mode of action and regulation of BPI is discussed in this chapter. The subsequent sections describe the diseases associated with Dysregulation of BPI and the use of BPI as a therapeutic agent in various diseases. Towards the end, the objective of the present study is discussed. BPI is primarily known to be expressed in human neutrophils and epithelial cells. Previous studies have shown that among innate immune cells, murine BPI is expressed only in dendritic cells and neutrophils, but not in macrophages. Based on these results, it was presumed that BPI is not expressed in human macrophages. In Chapter 2, we report the presence of BPI in human macrophages. Our studies revealed increased expression of BPI in human macrophages stimulated with various PAMPs (Pathogen-associated molecular patterns) viz., LPS, flagellin as well as during bacterial infection. Further, during the course of an infection, BPI interacted with Gram-negative bacteria, resulting in enhanced phagocytosis and subsequent control of the bacterial replication. However, it was observed that bacteria which can maintain an active replicating niche (Salmonella Typhimurium) avoid the interaction with BPI during later stages of infection. On the other hand Salmonella mutants, which cannot maintain a replicating niche, as well as Shigella flexneri, which quit the endosomal vesicle, showed interaction with BPI. BPI was induced in both M1 and M2 differentiated macrophages suggesting its role in limiting Gram-negative bacteria and parasitic infection. These results propose an active role of BPI in Gram-negative bacterial clearance by human macrophages. This chapter concludes with a discussion on the importance of BPI expression in human but not murine macrophages. The importance of maintaining an active replicating niche by STM to evade interaction with BPI is also discussed. As the first line of defense against invading pathogens, intestinal epithelium produces various antimicrobial proteins (AMP) that help with clearance of pathogen. The precise mechanism of AMP regulation in intestinal epithelium is not clear. Intestinal epithelium being a primary entry point for various pathogens, we tried to understand the regulation of BPI expression in the intestine during the course of bacterial infection. In Chapter 3, we report a direct correlation between intestinal damage and BPI expression. In Caco-2 cells, we see a significant increase in BPI levels upon membrane damage mediated by S.aureus infection and pore-forming toxins (Streptolysin and Listeriolysin). Cells detect changes in potassium levels as a Danger-associated molecular pattern (DAMP) associated with cell damage and induce BPI expression in a p38 dependent manner. These results are further supported by in vivo findings that BPI expression in the murine intestinal epithelium is induced upon infection with bacteria which cause intestinal damage (Salmonella Typhimurium & Shigella flexneri) whereas mutants which don’t cause intestinal damage (STM fliC & STM invC), didn’t induce BPI expression. These findings have a huge impact on our current understanding of AMP response during inflammatory bowel diseases (IBD). Our results suggest that dysregulation of BPI expression might be an effect rather than a cause of IBD. This chapter concludes with a discussion on the importance of potassium efflux associated with membrane damage as an important signal that helps in discriminating the invading pathogen from the pool of gut microflora. Bactericidal/permeability-increasing protein had been shown to possess anti-inflammatory and endotoxin neutralizing activity by interacting with LPS of Gram-negative bacteria. Even though rBPI (recombinant BPI) has cleared phase III clinical trials for treating endotoxemia, the high cost of purified BPI provided by pharmaceutical companies makes it inaccessible or unavailable for the common man. In Chapter 4, we examined the feasibility of using murine BPI (mBPI) expressed on halophilic Archaeal gas vesicle nanoparticles (GVNPs) for the treatment of endotoxemia in high-risk patients, using a murine model of D-galactosamine-induced endotoxic shock. Halobacterium sp. NRC-1 was used to express the N-terminal 199 amino acid residues of mBPI fused to the GVNP GvpC protein, and bound to the surface of the haloarchaeal GVNPs. Our results indicate that delivery of mBPIN-GVNPs increase the survival rate of mice challenged with lethal concentrations of lipopolysaccharide (LPS) and D-galactosamine. Additionally, the mBPIN-GVNP-treated mice displayed reduced symptoms of inflammation including inflammatory anemia, recruitment of neutrophils, liver apoptosis and pro-inflammatory serum cytokine levels. This chapter concludes with a discussion of the advantages of using mBPIN-GVNPs over purified protein in treating endotoxic shock.

Indiana University-Purdue University Indianapolis (IUPUI) / The immune system initiates tissue repair following injury. In response to sterile tissue injury, neutrophils infiltrate the tissue to remove tissue debris and subsequently undergo apoptosis. Proper clearance of apoptotic neutrophils in the tissue by recruited macrophages, in a process termed efferocytosis, is critical to facilitate the resolution of inflammation and tissue repair. However, the events leading to suppression of sterile inflammation following efferocytosis, and the contribution of other innate cell types are not clearly defined in an in vivo setting. Using a sterile mouse peritonitis model, we identified IL-4 production from efferocytosing macrophages in the peritoneum that activate invariant NKT cells to produce cytokines including IL-4 and IL-13. Importantly, IL-4 from macrophages functions in autocrine and paracrine circuits to promote alternative activation of peritoneal exudate macrophages and augment type-2 cytokine production from NKT cells to suppress inflammation. The increased peritonitis in mice deficient in IL-4, NKT cells, or IL-4Ra expression on myeloid cells suggested that each is a key component for resolution of sterile inflammation. The phagocyte NADPH oxidase, a multi-subunit enzyme complex we demonstrated to require a physical interaction between the Rac GTPase and the oxidase subunit gp91phox for generation of reactive oxygen species (ROS), is required for production of ROS within macrophage phagosomes containing ingested apoptotic cells. In mice with X-linked chronic granulomatous disease (X-CGD) that lack gp91phox, efferocytosing macrophages were unable to produce ROS and were defective in activating iNKT during sterile peritonitis, resulting in enhanced and prolonged inflammation. Thus, efferocytosis-induced IL-4 production and activation of IL-4-producing iNKT cells by macrophages are immunomodulatory events in an innate immune circuit required to resolve sterile inflammation and promote tissue repair.