title: Immunophenotypic and Ultrastructural Analysis of Mast Cells in Hermansky-Pudlak Syndrome Type-1: A Possible Connection to Pulmonary Fibrosis.
abstract: 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.
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Arnold S
authors.initials: AS
authors.lastname: Kirshenbaum
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Glenn
authors.initials: G
authors.lastname: Cruse
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Avanti
authors.initials: A
authors.lastname: Desai
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Geethani
authors.initials: G
authors.lastname: Bandara
authors.affiliation: Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Maarten
authors.initials: M
authors.lastname: Leerkes
authors.affiliation: Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Chyi-Chia R
authors.initials: CC
authors.lastname: Lee
authors.affiliation: Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Fischer
authors.affiliation: Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: O'Brien
authors.affiliation: Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Bernadette R
authors.initials: BR
authors.lastname: Gochuico
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Kelly
authors.initials: K
authors.lastname: Stone
authors.affiliation: Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America.|Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: William A
authors.initials: WA
authors.lastname: Gahl
authors.affiliation: Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Dean D
authors.initials: DD
authors.lastname: Metcalfe
mesh_terms: D000328:Adult; D015415:Biomarkers; D016022:Case-Control Studies; D002460:Cell Line; D002478:Cells, Cultured; D002633:Chemotaxis; D016000:Cluster Analysis; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D022861:Hermanski-Pudlak Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D000068877:Imatinib Mesylate / Q000494:pharmacology; D016130:Immunophenotyping; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure*; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers; C102160:HPS1 protein, human; D008565:Membrane Proteins; D000068877:Imatinib Mesylate