Immunophenotypic and Ultrastructural Analysis of Mast Cells in Hermansky-Pudlak Syndrome Type-1: A Possible Connection to Pulmonary Fibrosis

• Published in: PloS one Vol. 11; no. 7; p. e0159177
• Main Authors: Kirshenbaum, Arnold S, Cruse, Glenn, Desai, Avanti, Bandara, Geethani, Leerkes, Maarten, Lee, Chyi-Chia R, Fischer, Elizabeth R, O'Brien, Kevin J, Gochuico, Bernadette R, Stone, Kelly, Gahl, William A, Metcalfe, Dean D
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26.07.2016; Public Library of Science (PLoS)
• Subjects: Adult; Agglomeration; Albinism; Allergies; Alveoli; Analysis; Automation; Biology and Life Sciences; Biomarkers; Biopsy; Bleeding; Case-Control Studies; CD34 antigen; CD63 antigen; Cell culture; Cell Line; Cells, Cultured; Chemotaxis; Cluster Analysis; Colitis; Cytokines; Degranulation; Diagnosis; Extracellular matrix; Extracellular Matrix - metabolism; Female; Fibronectin; Fibrosis; Galectin-3; Gene expression; Gene Expression Profiling; Gene mutation; Genomes; Granular materials; Granule cells; Health aspects; Hereditary diseases; Hermanski-Pudlak Syndrome - diagnosis; Hermanski-Pudlak Syndrome - genetics; Hermanski-Pudlak Syndrome - metabolism; Hermansky-Pudlak syndrome; Humans; Imatinib Mesylate - pharmacology; Immune response; Immune system; Immunophenotyping; Infectious diseases; Interleukin 6; Interleukin 8; Laboratories; Lung - metabolism; Lung - pathology; Lung diseases; Male; Mast cells; Mast Cells - drug effects; Mast Cells - metabolism; Mast Cells - ultrastructure; Medicine and Health Sciences; Melanosomes; Membrane Proteins - genetics; Middle Aged; Mutation; Oculocutaneous albinism; Patients; Phenotype; Platelets; Proteins; Pulmonary Alveoli - metabolism; Pulmonary Alveoli - pathology; Pulmonary fibrosis; Pulmonary Fibrosis - etiology; Pulmonary Fibrosis - metabolism; Pulmonary Fibrosis - pathology; Research and Analysis Methods; Risk factors; Skin; Surface activation; Young Adult
• DOI: 10.1371/journal.pone.0159177
• ISSN: 1932-6203

Hermansky-Pudlak Syndrome type-1 (HPS-1) is an autosomal recessive disorder caused by mutations in HPS1 which result in reduced expression of the HPS-1 protein, defective lysosome-related organelle (LRO) transport and absence of platelet delta granules. Patients with HPS-1 exhibit oculocutaneous albinism, colitis, bleeding and pulmonary fibrosis postulated to result from a dysregulated immune response. The effect of the HPS1 mutation on human mast cells (HuMCs) is unknown. Since HuMC granules classify as LROs along with platelet granules and melanosomes, we set out to determine if HPS-1 cutaneous and CD34+ culture-derived HuMCs have distinct granular and cellular characteristics. Cutaneous and cultured CD34+-derived HuMCs from HPS-1 patients were compared with normal cutaneous and control HuMCs, respectively, for any morphological and functional differences. One cytokine-independent HPS-1 culture was expanded, cloned, designated the HP proMastocyte (HPM) cell line and characterized. HPS-1 and idiopathic pulmonary fibrosis (IPF) alveolar interstitium showed numerous HuMCs; HPS-1 dermal mast cells exhibited abnormal granules when compared to healthy controls. HPS-1 HuMCs showed increased CD63, CD203c and reduced mediator release following FcɛRI aggregation when compared with normal HuMCs. HPM cells also had the duplication defect, expressed FcɛRI and intracytoplasmic proteases and exhibited less mediator release following FcɛRI aggregation. HPM cells constitutively released IL-6, which was elevated in patients' serum, in addition to IL-8, fibronectin-1 (FN-1) and galectin-3 (LGALS3). Transduction with HPS1 rescued the abnormal HPM morphology, cytokine and matrix secretion. Microarray analysis of HPS-1 HuMCs and non-transduced HPM cells confirmed upregulation of differentially expressed genes involved in fibrogenesis and degranulation. Cultured HPS-1 HuMCs appear activated as evidenced by surface activation marker expression, a decrease in mediator content and impaired releasibility. The near-normalization of constitutive cytokine and matrix release following rescue by HPS1 transduction of HPM cells suggests that HPS-1 HuMCs may contribute to pulmonary fibrosis and constitute a target for therapeutic intervention.