ABSTRACT
Cellular therapies with cardiomyocytes produced from induced pluripotent stem cells (iPSC-CMs) offer a potential route to cardiac regeneration as a treatment for chronic ischemic heart disease. Here, we report successful long-term engraftment and in vivo maturation of autologous iPSC-CMs in two rhesus macaques with small, subclinical chronic myocardial infarctions, all without immunosuppression. Longitudinal positron emission tomography imaging using the sodium/iodide symporter (NIS) reporter gene revealed stable grafts for over 6 and 12 months, with no teratoma formation. Histological analyses suggested capability of the transplanted iPSC-CMs to mature and integrate with endogenous myocardium, with no sign of immune cell infiltration or rejection. By contrast, allogeneic iPSC-CMs were rejected within 8 weeks of transplantation. This study provides the longest-term safety and maturation data to date in any large animal model, addresses concerns regarding neoantigen immunoreactivity of autologous iPSC therapies, and suggests that autologous iPSC-CMs would similarly engraft and mature in human hearts.
Subject(s)
Induced Pluripotent Stem Cells , Macaca mulatta , Myocytes, Cardiac , Animals , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/cytology , Cell Differentiation , Humans , Transplantation, Autologous , Positron-Emission Tomography , Time Factors , Myocardial Infarction/therapy , Myocardial Infarction/pathologyABSTRACT
Neutrophils play important roles in inflammatory airway diseases. In this study, we assessed whether apolipoprotein A-I modifies neutrophil heterogeneity as part of the mechanism by which it attenuates acute airway inflammation. Neutrophilic airway inflammation was induced by daily intranasal administration of LPS plus house dust mite (LPS+HDM) to Apoa1-/- and Apoa1+/+ mice for 3 d. Single-cell RNA sequencing was performed on cells recovered from bronchoalveolar lavage fluid on day 4. Unsupervised profiling identified 10 clusters of neutrophils in bronchoalveolar lavage fluid from Apoa1-/- and Apoa1+/+ mice. LPS+HDM-challenged Apoa1-/- mice had an increased proportion of the Neu4 neutrophil cluster that expressed S100a8, S100a9, and Mmp8 and had high maturation, aggregation, and TLR4 binding scores. There was also an increase in the Neu6 cluster of immature neutrophils, whereas neutrophil clusters expressing IFN-stimulated genes were decreased. An unsupervised trajectory analysis showed that Neu4 represented a distinct lineage in Apoa1-/- mice. LPS+HDM-challenged Apoa1-/- mice also had an increased proportion of recruited airspace macrophages, which was associated with a reciprocal reduction in resident airspace macrophages. Increased expression of a common set of proinflammatory genes, S100a8, S100a9, and Lcn2, was present in all neutrophils and airspace macrophages from LPS+HDM-challenged Apoa1-/- mice. These findings show that Apoa1-/- mice have increases in specific neutrophil and macrophage clusters in the lung during acute inflammation mediated by LPS+HDM, as well as enhanced expression of a common set of proinflammatory genes. This suggests that modifications in neutrophil and macrophage heterogeneity contribute to the mechanism by which apolipoprotein A-I attenuates acute airway inflammation.
Subject(s)
Apolipoprotein A-I , Mice, Knockout , Neutrophils , Pneumonia , Animals , Mice , Neutrophils/immunology , Pneumonia/immunology , Pneumonia/genetics , Apolipoprotein A-I/genetics , Mice, Inbred C57BL , Lipopolysaccharides/immunology , Bronchoalveolar Lavage Fluid/immunology , Bronchoalveolar Lavage Fluid/cytology , Lung/immunology , Lung/pathology , Calgranulin A , Calgranulin BABSTRACT
BACKGROUND: House dust mite (HDM)-challenged Apoe-/- mice display enhanced airway hyperreactivity and mucous cell metaplasia. OBJECTIVE: We sought to characterize the pathways that induce apolipoprotein E (APOE) expression by bronchoalveolar lavage fluid (BALF) macrophages from asthmatic subjects and identify how APOE regulates IL-1ß secretion. METHODS: Macrophages were isolated from asthmatic BALF and derived from THP-1 cells and human monocytes. RESULTS: HDM-derived cysteine and serine proteases induced APOE secretion from BALF macrophages through protease-activated receptor 2. APOE at concentrations of less than 2.5 nmol/L, which are similar to levels found in epithelial lining fluid from healthy adults, did not induce IL-1ß release from BALF macrophages. In contrast, APOE at concentrations of 25 nmol/L or greater induced nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein (NLRP) 3 and pro-IL-1ß expression by BALF macrophages, as well as the caspase-1-mediated generation of mature IL-1ß secreted from cells. HDM acted synergistically with APOE to both prime and activate the NLRP3 inflammasome. In a murine model of neutrophilic airway inflammation induced by HDM and polyinosinic-polycytidylic acid, APOE reached a concentration of 32 nmol/L in epithelial lining fluid, with associated increases in BALF IL-1ß levels. APOE-dependent NLRP3 inflammasome activation in macrophages was primarily mediated through a potassium efflux-dependent mechanism. CONCLUSION: APOE can function as an endogenous, concentration-dependent pulmonary danger signal that primes and activates the NLPR3 inflammasome in BALF macrophages from asthmatic subjects to secrete IL-1ß. This might represent a mechanism through which APOE amplifies pulmonary inflammatory responses when concentrations in the lung are increased to greater than normal levels, which can occur during viral exacerbations of HDM-induced asthma characterized by neutrophilic airway inflammation.
Subject(s)
Apolipoproteins E/immunology , Asthma/immunology , Bronchoalveolar Lavage Fluid/immunology , Inflammasomes/immunology , Interleukin-1beta/immunology , Macrophages/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Signal Transduction/immunology , Animals , Asthma/pathology , Female , Humans , Macrophages/pathology , Male , Mice , THP-1 CellsABSTRACT
BACKGROUND: Low-density lipoprotein receptor-related protein 1 (LRP-1) is a scavenger receptor that regulates adaptive immunity and inflammation. LRP-1 is not known to modulate the pathogenesis of allergic asthma. OBJECTIVE: We sought to assess whether LRP-1 expression by dendritic cells (DCs) modulates adaptive immune responses in patients with house dust mite (HDM)-induced airways disease. METHODS: LRP-1 expression on peripheral blood DCs was quantified by using flow cytometry. The role of LRP-1 in modulating HDM-induced airways disease was assessed in mice with deletion of LRP-1 in CD11c+ cells (Lrp1fl/fl; CD11c-Cre) and by adoptive transfer of HDM-pulsed CD11b+ DCs from Lrp1fl/fl; CD11c-Cre mice to wild-type (WT) mice. RESULTS: Human peripheral blood myeloid DC subsets from patients with eosinophilic asthma have lower LRP-1 expression than cells from healthy nonasthmatic subjects. Similarly, LRP-1 expression by CD11b+ lung DCs was significantly reduced in HDM-challenged WT mice. HDM-challenged Lrp1fl/fl; CD11c-Cre mice have a phenotype of increased eosinophilic airway inflammation, allergic sensitization, TH2 cytokine production, and mucous cell metaplasia. The adoptive transfer of HDM-pulsed LRP-1-deficient CD11b+ DCs into WT mice generated a similar phenotype of enhanced eosinophilic inflammation and allergic sensitization. Furthermore, CD11b+ DCs in the lungs of Lrp1fl/fl; CD11c-Cre mice have an increased ability to take up HDM antigen, whereas bone marrow-derived DCs display enhanced antigen presentation capabilities. CONCLUSION: This identifies a novel role for LRP-1 as a negative regulator of DC-mediated adaptive immune responses in the setting of HDM-induced eosinophilic airway inflammation. Furthermore, the reduced LRP-1 expression by circulating myeloid DCs in patients with eosinophilic asthma suggests a possible role for LRP-1 in modulating type 2-high asthma.
Subject(s)
Asthma/immunology , Dendritic Cells/immunology , Dermatophagoides pteronyssinus/immunology , Eosinophilia/immunology , Low Density Lipoprotein Receptor-Related Protein-1/immunology , Adaptive Immunity , Adult , Allergens/immunology , Animals , Antigens, Dermatophagoides/immunology , Asthma/blood , Asthma/physiopathology , Bronchoalveolar Lavage Fluid/cytology , Eosinophilia/blood , Eosinophilia/physiopathology , Female , Humans , Immunoglobulin E/blood , Immunoglobulin G/blood , Male , Mice, Transgenic , Middle AgedABSTRACT
Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but regardless of the approach, an in vivo model is needed to test each treatment. The pig is one of the most used large animal models for cardiovascular disease. Its heart is very similar in anatomy and function to that of a human. The ameroid placement technique creates an ischemic area of the heart, which has many useful applications in studying myocardial infarction. This model has been used for surgical research, pharmaceutical studies, imaging techniques, and cell therapies. There are several ways of inducing an ischemic area in the heart. Each has its advantages and disadvantages, but the placement of an ameroid constrictor remains the most widely used technique. The main advantages to using the ameroid are its prevalence in existing research, its availability in various sizes to accommodate the anatomy and size of the vessel to be constricted, the surgery is a relatively simple procedure, and the post-operative monitoring is minimal, since there are no external devices to maintain. This paper provides a detailed overview of the proper technique for the placement of the ameroid constrictor.
Subject(s)
Caseins/pharmacology , Hydrogels/pharmacology , Myocardial Ischemia/physiopathology , Animals , Chronic Disease , Disease Models, Animal , Humans , SwineABSTRACT
DNA-dependent protein kinase (DNA-PK) mediates double-stranded DNA break repair, V(D)J recombination and immunoglobulin class switch recombination, as well as innate immune and pro-inflammatory responses. However, there is limited information regarding the role of DNA-PK in adaptive immunity mediated by dendritic cells (DCs), which are the primary antigen-presenting cells in allergic asthma. Here we show that house dust mite induces DNA-PK phosphorylation, which is a marker of DNA-PK activation, in DCs via the generation of intracellular reactive oxygen species. We also demonstrate that pharmacological inhibition of DNA-PK, as well as the specific deletion of DNA-PK in DCs, attenuates the induction of allergic sensitization and Th2 immunity via a mechanism that involves the impaired presentation of mite antigens. Furthermore, pharmacological inhibition of DNA-PK following antigen priming similarly reduces the manifestations of mite-induced airway disease. Collectively, these findings suggest that DNA-PK may be a potential target for treatment of allergic asthma.
Subject(s)
DNA-Activated Protein Kinase/metabolism , DNA-Binding Proteins/metabolism , Dendritic Cells/immunology , Inflammation/immunology , Nuclear Proteins/metabolism , Th2 Cells/immunology , Adaptive Immunity , Administration, Oral , Animals , Antigen Presentation , Asthma/immunology , CD11c Antigen/metabolism , Chromones/chemistry , Dendritic Cells/parasitology , Female , Hypersensitivity/immunology , Immunoglobulin E/immunology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, SCID , Morpholines/chemistry , Phosphorylation , Pyroglyphidae , Reactive Oxygen Species/metabolism , Th2 Cells/parasitologyABSTRACT
Apolipoprotein A-I (apoA-I) is an important component of high-density lipoprotein particles that mediates reverse cholesterol transport out of cells by interacting with the ATP-binding cassette transporter 1 (ABCA1). apoA-I has also been shown to attenuate neutrophilic airway inflammation in experimental ovalbumin (OVA)-induced asthma by reducing the expression of granulocyte colony-stimulating factor (G-CSF). Here, we hypothesized that overexpression of the ABCA1 transporter might similarly attenuate OVA-induced neutrophilic airway inflammation. Tie2-human ABCA1 (hABCA1) mice expressing human ABCA1 under the control of the Tie2 promoter, which is primarily expressed by vascular endothelial cells, but can also be expressed by macrophages, received daily intranasal OVA challenges, 5 d/wk for 5 weeks. OVA-challenged Tie2-hABCA1 mice had significant reductions in total bronchoalveolar lavage fluid (BALF) cells that reflected a decrease in neutrophils, as well as reductions in peribronchial inflammation, OVA-specific IgE levels, and airway epithelial thickness. The reduced airway neutrophilia in OVA-challenged Tie2-hABCA1 mice was associated with significant decreases in G-CSF protein levels in pulmonary vascular endothelial cells, alveolar macrophages, and BALF. Intranasal administration of recombinant murine G-CSF to OVA-challenged Tie2-hABCA1 mice for 5 days increased BALF neutrophils to a level comparable to that of OVA-challenged wild-type mice. We conclude that ABCA1 suppresses OVA-induced airway neutrophilia by reducing G-CSF production by vascular endothelial cells and alveolar macrophages. These findings suggest that ABCA1 expressed by vascular endothelial cells and alveolar macrophages may play important roles in attenuating the severity of neutrophilic airway inflammation in asthma.
Subject(s)
ATP Binding Cassette Transporter 1/genetics , ATP Binding Cassette Transporter 1/immunology , Neutrophils/immunology , Pneumonia/immunology , Animals , Asthma/immunology , Bronchoalveolar Lavage Fluid/immunology , Cholesterol/immunology , Endothelial Cells/immunology , Granulocyte Colony-Stimulating Factor/genetics , Humans , Macrophages, Alveolar/immunology , Mice, Inbred C57BL , Mice, Transgenic , Ovalbumin/immunology , Ovalbumin/pharmacology , Pneumonia/chemically induced , Promoter Regions, Genetic/genetics , Receptor, TIE-2/geneticsABSTRACT
The very low density lipoprotein receptor (VLDLR) is a member of the low-density lipoprotein receptor family that binds multiple ligands and plays a key role in brain development. Although the VLDLR mediates pleiotropic biological processes, only a limited amount of information is available regarding its role in adaptive immunity. In this study, we identify an important role for the VLDLR in attenuating house dust mite (HDM)-induced airway inflammation in experimental murine asthma. We show that HDM-challenged Vldlr(-/-) mice have augmented eosinophilic and lymphocytic airway inflammation with increases in Th2 cytokines, C-C chemokines, IgE production, and mucous cell metaplasia. A genome-wide analysis of the lung transcriptome identified that mRNA levels of CD209e (DC-SIGNR4), a murine homolog of DC-SIGN, were increased in the lungs of HDM-challenged Vldlr(-/-) mice, which suggested that the VLDLR might modify dendritic cell (DC) function. Consistent with this, VLDLR expression by human monocyte-derived DCs was increased by HDM stimulation. In addition, 55% of peripheral blood CD11c(+) DCs from individuals with allergy expressed VLDLR under basal conditions. Lastly, the adoptive transfer of HDM-pulsed, CD11c(+) bone marrow-derived DCs (BMDCs) from Vldlr(-/-) mice to the airways of wild type recipient mice induced augmented eosinophilic and lymphocytic airway inflammation upon HDM challenge with increases in Th2 cytokines, C-C chemokines, IgE production, and mucous cell metaplasia, as compared with the adoptive transfer of HDM-pulsed, CD11c(+) BMDCs from wild type mice. Collectively, these results identify a novel role for the VLDLR as a negative regulator of DC-mediated adaptive immune responses in HDM-induced allergic airway inflammation.
Subject(s)
Adaptive Immunity , Dendritic Cells/immunology , Pyroglyphidae , Receptors, LDL/immunology , Respiratory Hypersensitivity/immunology , Animals , CD11c Antigen/genetics , CD11c Antigen/immunology , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/immunology , Cytokines/genetics , Cytokines/immunology , Dendritic Cells/pathology , Eosinophils/immunology , Eosinophils/pathology , Female , Genome-Wide Association Study , Humans , Immunoglobulin E/genetics , Immunoglobulin E/immunology , Lectins, C-Type/genetics , Lectins, C-Type/immunology , Male , Mice , Mice, Knockout , Receptors, Cell Surface/genetics , Receptors, Cell Surface/immunology , Receptors, LDL/genetics , Respiratory Hypersensitivity/genetics , Respiratory Hypersensitivity/pathology , Th2 Cells/immunology , Th2 Cells/pathologyABSTRACT
Peptidoglycan recognition protein (Pglyrp) 1 is a pattern-recognition protein that mediates antibacterial host defense. Because we had previously shown that Pglyrp1 expression is increased in the lungs of house dust mite (HDM)-challenged mice, we hypothesized that it might modulate the pathogenesis of asthma. Wild-type and Pglyrp1(-/-) mice on a BALB/c background received intranasal HDM or saline, 5 days/week for 3 weeks. HDM-challenged Pglyrp1(-/-) mice showed decreases in bronchoalveolar lavage fluid eosinophils and lymphocytes, serum IgE, and mucous cell metaplasia, whereas airway hyperresponsiveness was not changed when compared with wild-type mice. T helper type 2 (Th2) cytokines were reduced in the lungs of HDM-challenged Pglyrp1(-/-) mice, which reflected a decreased number of CD4(+) Th2 cells. There was also a reduction in C-C chemokines in bronchoalveolar lavage fluid and lung homogenates from HDM-challenged Pglyrp1(-/-) mice. Furthermore, secretion of CCL17, CCL22, and CCL24 by alveolar macrophages from HDM-challenged Pglyrp1(-/-) mice was markedly reduced. As both inflammatory cells and airway epithelial cells express Pglyrp1, bone marrow transplantation was performed to generate chimeric mice and assess which cell type promotes HDM-induced airway inflammation. Chimeric mice lacking Pglyrp1 on hematopoietic cells, not structural cells, showed a reduction in HDM-induced eosinophilic and lymphocytic airway inflammation. We conclude that Pglyrp1 expressed by hematopoietic cells, such as alveolar macrophages, mediates HDM-induced airway inflammation by up-regulating the production of C-C chemokines that recruit eosinophils and Th2 cells to the lung. This identifies a new family of innate immune response proteins that promotes HDM-induced airway inflammation in asthma.
Subject(s)
Asthma/etiology , Cytokines/immunology , Dermatophagoides pteronyssinus/immunology , Allergens/administration & dosage , Animals , Antigens, Dermatophagoides/administration & dosage , Asthma/immunology , Asthma/pathology , Chemokines, CC/biosynthesis , Cytokines/deficiency , Cytokines/genetics , Disease Models, Animal , Eosinophils/immunology , Eosinophils/pathology , Immunity, Innate , Lung/immunology , Lung/pathology , Macrophages, Alveolar/immunology , Macrophages, Alveolar/pathology , Mice , Mice, Inbred BALB C , Mice, Knockout , Th2 Cells/immunology , Transplantation Chimera/immunology , Up-RegulationABSTRACT
The mammalian target of rapamycin (mTOR) modulates immune responses and cellular proliferation. The objective of this study was to assess whether inhibition of mTOR with rapamycin modifies disease severity in two experimental murine models of house dust mite (HDM)-induced asthma. In an induction model, rapamycin was administered to BALB/c mice coincident with nasal HDM challenges for 3 weeks. In a treatment model, nasal HDM challenges were performed for 6 weeks and rapamycin treatment was administered during weeks 4 through 6. In the induction model, rapamycin significantly attenuated airway inflammation, airway hyperreactivity (AHR) and goblet cell hyperplasia. In contrast, treatment of established HDM-induced asthma with rapamycin exacerbated AHR and airway inflammation, whereas goblet cell hyperplasia was not modified. Phosphorylation of the S6 ribosomal protein, which is downstream of mTORC1, was increased after 3 weeks, but not 6 weeks of HDM-challenge. Rapamycin reduced S6 phosphorylation in HDM-challenged mice in both the induction and treatment models. Thus, the paradoxical effects of rapamycin on asthma severity paralleled the activation of mTOR signaling. Lastly, mediastinal lymph node re-stimulation experiments showed that treatment of rapamycin-naive T cells with ex vivo rapamycin decreased antigen-specific Th2 cytokine production, whereas prior exposure to in vivo rapamycin rendered T cells refractory to the suppressive effects of ex vivo rapamycin. We conclude that rapamycin had paradoxical effects on the pathogenesis of experimental HDM-induced asthma. Thus, consistent with the context-dependent effects of rapamycin on inflammation, the timing of mTOR inhibition may be an important determinant of efficacy and toxicity in HDM-induced asthma.
Subject(s)
Asthma/drug therapy , Asthma/etiology , Pyroglyphidae/immunology , Sirolimus/therapeutic use , Animals , Asthma/immunology , Asthma/metabolism , Bronchoalveolar Lavage Fluid/chemistry , Female , Inflammation/drug therapy , Inflammation/etiology , Inflammation/immunology , Inflammation/metabolism , Lung/drug effects , Lung/immunology , Lung/metabolism , Mice , Mice, Inbred BALB C , Phosphorylation/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Signal Transduction/genetics , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolismABSTRACT
Apolipoprotein A-I (apoA-I) is a key component of high-density lipoproteins that mediates reverse cholesterol transport from cells and reduces vascular inflammation. We investigated whether endogenous apoA-I modulates ovalbumin (OVA)-induced airway inflammation in mice. We found that apoA-I expression was significantly reduced in the lungs of OVA-challenged, compared with saline-challenged, wild-type (WT) mice. Next, to investigate the role of endogenous apoA-I in the pathogenesis of OVA-induced airway inflammation, WT and apoA-I(-/-) mice were sensitized by intraperitoneal injections of OVA and aluminum hydroxide, followed by multiple nasal OVA challenges for 4 weeks. OVA-challenged apoA-I(-/-) mice exhibited a phenotype of increased airway neutrophils compared with WT mice, which could be rescued by an administration of a 5A apoA-I mimetic peptide. Multiple pathways promoted neutrophilic inflammation in OVA-challenged apoA-I(-/-) mice, including the up-regulated expression of (1) proinflammatory cytokines (IL-17A and TNF-α), (2) CXC chemokines (CXCL5), (3) vascular adhesion molecules (i.e., vascular cell adhesion molecule-1), and (4) granulocyte colony-stimulating factors (G-CSF). Because concentrations of G-CSF in bronchoalveolar lavage fluid (BALF) were markedly increased in OVA-challenged apoA-I(-/-) mice, we hypothesized that enhanced G-CSF expression may represent the predominant pathway mediating increased neutrophilic inflammation. This was confirmed by the intranasal administration of a neutralizing anti-G-CSF antibody, which significantly reduced BALF neutrophilia by 72% in OVA-challenged apoA-I(-/-) mice, compared with mice that received a control antibody. We conclude that endogenous apoA-I negatively regulates OVA-induced neutrophilic airway inflammation, primarily via a G-CSF-dependent mechanism. Furthermore, these findings suggest that apoA-I may play an important role in modulating the severity of neutrophilic airway inflammation in asthma.
Subject(s)
Apolipoprotein A-I/immunology , Granulocyte Colony-Stimulating Factor/immunology , Inflammation/drug therapy , Inflammation/immunology , Neutrophils/immunology , Ovalbumin/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/pharmacology , Apolipoprotein A-I/genetics , Apolipoprotein A-I/metabolism , Asthma/genetics , Asthma/immunology , Asthma/metabolism , Bronchoalveolar Lavage Fluid/immunology , Chemokine CXCL5/genetics , Chemokine CXCL5/immunology , Chemokine CXCL5/metabolism , Down-Regulation , Granulocyte Colony-Stimulating Factor/metabolism , Inflammation/metabolism , Interleukin-17/genetics , Interleukin-17/immunology , Interleukin-17/metabolism , Lung/immunology , Lung/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neutrophils/drug effects , Neutrophils/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism , Up-Regulation , Vascular Cell Adhesion Molecule-1/genetics , Vascular Cell Adhesion Molecule-1/immunologyABSTRACT
Apolipoprotein E (apoE) is an endogenous negative regulator of airway hyperreactivity (AHR) and mucous cell metaplasia in experimental models of house dust mite (HDM)-induced airway disease. The gene encoding human apoE is polymorphic, with three common alleles (ε2, ε3, and ε4) reflecting single amino acid substitutions at amino acids 112 and 158. The objective of this study was to assess whether the human apoE alleles modify airway responses to repeated nasal HDM challenges. Mice expressing the human apoE ε2 (huApoE2), ε3 (huApoE3), or ε4 (huApoE4) alleles received nasal HDM challenges, and airway responses were compared with mice expressing the endogenous murine apoE gene (muApoE). huApoE3 mice displayed significant reductions in AHR, mucous cell metaplasia, and airway inflammation compared with muApoE mice. The attenuated severity of airway inflammation in huApoE3 mice was associated with reductions in lung mRNA levels of Th2 and Th17 cytokines, as well as chemokines (CCL7, CCL11, CCL24). huApoE4 mice had an intermediate phenotype, with attenuated AHR and IgE production, compared with muApoE mice, whereas airway inflammation and mucous cell metaplasia were not reduced. In contrast, HDM-induced airway responses were not modified in mice expressing the huApoE2 allele. We conclude that the polymorphic huApoE alleles differentially modulate HDM-induced airway disease, which can be stratified, in rank order of increasing disease severity, ε3 < ε4 < ε2. These results raise the possibility that the polymorphic apoE alleles may modify disease severity in human asthma.
Subject(s)
Allergens/immunology , Antigens, Dermatophagoides/immunology , Apolipoproteins E/genetics , Asthma/genetics , Bronchial Hyperreactivity/genetics , Alleles , Amino Acid Substitution , Animals , Apolipoproteins E/metabolism , Asthma/immunology , Asthma/pathology , Bronchial Hyperreactivity/immunology , Bronchial Hyperreactivity/pathology , Chemokine CCL11/biosynthesis , Chemokine CCL24/biosynthesis , Chemokine CCL7/biosynthesis , Cytokines/biosynthesis , Disease Models, Animal , Female , Gene Knock-In Techniques , Genotype , Immunoglobulin E/biosynthesis , Inflammation/genetics , Inflammation/immunology , Lung/immunology , Lung/pathology , Metaplasia , Mice , Mice, Inbred C57BL , Mice, Transgenic , RNA, Messenger/genetics , RNA, Messenger/metabolism , Th17 Cells/immunology , Th2 Cells/immunologyABSTRACT
New treatment approaches are needed for patients with asthma. Apolipoprotein A-I (apoA-I), the major structural protein of high-density lipoproteins, mediates reverse cholesterol transport and has atheroprotective and anti-inflammatory effects. In this study, we hypothesized that an apoA-I mimetic peptide might be effective at inhibiting asthmatic airway inflammation. A 5A peptide, which is a synthetic, bihelical apoA-I mimetic, was administered to wild-type A/J mice via osmotic mini-pump prior to the induction of house dust mite (HDM)-induced asthma. HDM-challenged mice that received the 5A apoA-I mimetic peptide had significant reductions in the number of bronchoalveolar lavage fluid eosinophils, lymphocytes, and neutrophils, as well as in histopathological evidence of airway inflammation. The reduction in airway inflammation was mediated by a reduction in the expression of Th2- and Th17-type cytokines, as well as in chemokines that promote T cell and eosinophil chemotaxis, including CCL7, CCL17, CCL11, and CCL24. Furthermore, the 5A apoA-I mimetic peptide inhibited the alternative activation of pulmonary macrophages in the lungs of HDM-challenged mice. It also abrogated the development of airway hyperresponsiveness and reduced several key features of airway remodeling, including goblet cell hyperplasia and the expression of collagen genes (Col1a1 and Col3a1). Our results demonstrate that the 5A apoA-I mimetic peptide attenuates the development of airway inflammation and airway hyperresponsiveness in an experimental murine model of HDM-induced asthma. These data support the conclusion that strategies using apoA-I mimetic peptides, such as 5A, might be developed further as a possible new treatment approach for asthma.
Subject(s)
Apolipoprotein A-I/administration & dosage , Asthma/immunology , Asthma/prevention & control , Molecular Mimicry/immunology , Peptide Fragments/administration & dosage , Pyroglyphidae/immunology , Administration, Inhalation , Animals , Anti-Asthmatic Agents/administration & dosage , Anti-Asthmatic Agents/therapeutic use , Apolipoprotein A-I/therapeutic use , Asthma/pathology , Bronchial Hyperreactivity/immunology , Bronchial Hyperreactivity/pathology , Bronchial Hyperreactivity/prevention & control , Cytokines/antagonists & inhibitors , Cytokines/biosynthesis , Disease Models, Animal , Female , Humans , Inflammation Mediators/antagonists & inhibitors , Inflammation Mediators/metabolism , Macrophage Activation/drug effects , Macrophage Activation/immunology , Mice , Mice, Inbred A , Peptide Fragments/therapeutic useABSTRACT
RATIONALE: Distinct sets of corticosteroid-unresponsive genes modulate disease severity in asthma. OBJECTIVES: To identify corticosteroid-unresponsive genes that provide new insights into disease pathogenesis and asthma therapeutics. METHODS: Experimental murine asthma was induced by nasal administration of house dust mite for 5 days per week. Dexamethasone and apolipoprotein E (apo E) mimetic peptides were administered via osmotic minipumps. MEASUREMENTS AND MAIN RESULTS: Genome-wide expression profiling of the lung transcriptome in a house dust mite-induced model of murine asthma identified increases in apo E mRNA levels that persisted despite corticosteroid treatment. House dust mite-challenged apo Eâ»(/)â» mice displayed enhanced airway hyperreactivity and goblet cell hyperplasia, which could be rescued by administration of an apo E(130-149) mimetic peptide. Administration of the apo E(130-149) mimetic peptide to house dust mite-challenged apo Eâ»(/)â» mice also inhibited eosinophilic airway inflammation, IgE production, and the expression of Th2 and Th17 cytokines. House dust mite-challenged low-density lipoprotein receptor (LDLR) knockout mice displayed a similar phenotype as apo Eâ»(/)â» mice with enhanced airway hyperreactivity, goblet cell hyperplasia, and mucin gene expression, but could not be rescued by the apo E(130-149) mimetic peptide, consistent with a LDLR-dependent mechanism. CONCLUSIONS: These findings for the first time identify an apo E-LDLR pathway as an endogenous negative regulator of airway hyperreactivity and goblet cell hyperplasia in asthma. Furthermore, our results demonstrate that strategies that activate the apo E-LDLR pathway, such as apo E mimetic peptides, might be developed into a novel treatment approach for patients with asthma.