ic-87114 and Inflammation

Topics: Animals; Autoimmune Diseases; B-Lymphocytes; Class Ia Phosphatidylinositol 3-Kinase; Class Ib Phosphatidylinositol 3-Kinase; Humans; Inflammation; Isoenzymes; Molecular Targeted Therapy; Neutrophils; Phosphoinositide-3 Kinase Inhibitors; Protein Conformation; T-Lymphocytes

Activated PI3-kinase delta syndrome (APDS) was recently reported as a novel primary immunodeficiency caused by heterozygous gain-of-function mutations in PIK3CD gene. Here we describe immunological studies in a 19year old APDS patient for whom genetic diagnosis was discovered by Whole Exome Sequencing (WES) analysis. In addition to the progressive lymphopenia and defective antibody production we showed that the ability of the patient's B cells to differentiate in vitro is severely reduced. An in depth analysis of the myeloid compartment showed an increased expression of CD83 activation marker on monocytes and mono-derived DC cells. Moreover, monocytes-derived macrophages (MDMs) failed to solve the Mycobacterium bovis bacillus Calmette Guèrin (BCG) infection in vitro. Selective p110δ inhibitor IC87114 restored the MDM capacity to kill BCG in vitro. Our data show that the constitutive activation of Akt-mTOR pathway induces important alterations also in the myeloid compartment providing new insights in order to improve the therapeutic approach in these patients.

Topics: Adenine; B-Lymphocytes; Cell Differentiation; Class I Phosphatidylinositol 3-Kinases; Dendritic Cells; Humans; Immunologic Deficiency Syndromes; In Vitro Techniques; Inflammation; Lymphopenia; Macrophages; Male; Mycobacterium bovis; Primary Immunodeficiency Diseases; Proto-Oncogene Proteins c-akt; Quinazolines; Signal Transduction; TOR Serine-Threonine Kinases; Young Adult

Sensitisation with Aspergillus fumigatus (Af) is known to be associated with severe allergic lung inflammation, but the mechanism remains to be clarified. Phosphoinositide 3-kinase (PI3K)-δ and endoplasmic reticulum (ER) stress are suggested to be involved in steroid-resistant lung inflammation. We aimed to elucidate the role of PI3K-δ and its relationship with ER stress in fungus-induced allergic lung inflammation.. Using Af-exposed in vivo and in vitro experimental systems, we examined whether PI3K-δ regulates ER stress, thereby contributing to steroid resistance in fungus-induced allergic lung inflammation. Moreover, we checked expression of an ER stress marker in lung tissues isolated from patients with allergic bronchopulmonary aspergillosis.. Af-exposed mice showed that ER stress markers, unfolded protein response (UPR)-related proteins, phosphorylated Akt, generation of mitochondrial reactive oxygen species (mtROS), eosinophilic allergic inflammation, and airway hyperresponsiveness (AHR) were increased in the lung. Similarly, glucose-regulated protein 78 was increased in lung tissues of patients with ABPA. A PI3K-δ inhibitor reduced Af-induced increases in ER stress markers, UPR-related proteins, allergic inflammation and AHR in mice. However, dexamethasone failed to reduce Af-induced allergic inflammation, AHR and elevation of ER stress. Administration of an ER stress inhibitor or a mtROS scavenger improved Af-induced allergic inflammation. The PI3K-δ inhibitor reduced Af-induced mtROS generation and the mtROS scavenger ameliorated ER stress. In primary cultured tracheal epithelial cells, Af-induced ER stress was inhibited by blockade of PI3K-δ.. These findings suggest that PI3K-δ regulates Af-induced steroid-resistant eosinophilic allergic lung inflammation through ER stress.

Topics: Adenine; Animals; Aspergillosis, Allergic Bronchopulmonary; Biomarkers; Blotting, Western; Bronchoalveolar Lavage; CCAAT-Enhancer-Binding Proteins; Endoplasmic Reticulum Stress; Female; Glutathione; Glutathione Disulfide; Immunoglobulin E; Inflammation; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Phosphatidylinositol 3-Kinases; Quinazolines; RNA, Small Interfering

PI3K/Akt pathway is a well-characterized pathway controlling cellular processes such as proliferation, migration and survival, and its role in cancer is vastly studied. There is also evidence to suggest the involvement of this pathway in the regulation of inflammatory responses. In this study, an attempt was made to investigate the role of PI3Ks in acute inflammation in vivo using pharmacological inhibitors against PI3Ks in the carrageenan-induced paw oedema model. A non-selective PI3K inhibitor LY294002 and a PI3Kδ-selective inhibitor IC87114 were used. Both of these inhibitors reduced inflammatory oedema upon carrageenan challenge in the mouse paw. To explain this result, the effects of the two inhibitors on inflammatory gene expression were investigated in activated macrophages. LY294002 and IC87114 prevented Akt phosphorylation as expected and down-regulated the expression of inflammatory factors IL-6, MCP-1,TNFα and iNOS. These findings suggest that PI3K inhibitors could be used to attenuate inflammatory responses and that the mechanism of action behind this effect is the down-regulation of inflammatory gene expression.

Topics: Adenine; Animals; Carrageenan; Chemokine CCL2; Chromones; Down-Regulation; Edema; Enzyme Inhibitors; Inflammation; Interleukin-6; Macrophages; Mice; Morpholines; Nitric Oxide Synthase Type II; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Quinazolines; Tumor Necrosis Factor-alpha

Although members of the class I phosphoinositide 3-kinases (PI3Ks) have been implicated in neutrophil inflammatory responses, the contribution of the individual PI3K isoforms in neutrophil activation has not been tractable with the non-selective inhibitors, LY294002 and wortmannin. We have developed a novel series of PI3K inhibitors that is selective for PI3K delta, an isoform expressed predominantly in hematopoietic cells. In addition to being selective between members of class I PI3Ks, representatives of these inhibitors such as IC980033 and IC87114 did not inhibit any protein kinases tested. Utilizing these inhibitors we report here a novel role for PI3K delta in neutrophil activation. Inhibition of PI3K delta with IC980033 and IC87114 blocked both fMLP- and TNF1 alpha-induced neutrophil superoxide generation and elastase exocytosis. The PI3K delta inhibitor IC87114 also blocked TNF1 alpha-stimulated elastase exocytosis from neutrophils in a mouse model of inflammation. To our knowledge, this is the first in vivo efficacy demonstration of a PI3K delta inhibitor in an animal model. Inhibition of PI3K delta, however, had no effect on in vitro neutrophil bactericidal activity and Fc gamma R-stimulated superoxide generation. Thus, PI3K delta plays an essential role in certain signaling pathways of neutrophil activation and appears to be an attractive target for the development of an anti-inflammatory therapeutic.

Topics: Adenine; Androstadienes; Animals; Anti-Inflammatory Agents; Chromones; Class I Phosphatidylinositol 3-Kinases; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Exocytosis; Inflammation; Leukocyte Elastase; Mice; Mice, Inbred BALB C; Morpholines; Neutrophils; Phosphatidylinositol 3-Kinases; Protein Isoforms; Quinazolines; Signal Transduction; Superoxides; Time Factors; Wortmannin