title: Characterization of a human surfactant protein A1 (SP-A1) gene-specific antibody; SP-A1 content variation among individuals of varying age and pulmonary health.
abstract: The human surfactant protein A (SP-A) locus consists of two functional genes (SP-A1, SP-A2) with gene-specific products exhibiting qualitative and quantitative differences. The aim here was twofold: 1) generate SP-A1 gene-specific antibody, and 2) use this to assess gene-specific SP-A content in the bronchoalveolar lavage fluid (BALF). An SP-A1-specific polyclonal antibody (hSP-A1_Ab(68-88)_Col) was raised in chicken, and its specificity was determined by immunoblot and ELISA using mammalian Chinese hamster ovary (CHO) cell-expressed SP-A1 and SP-A2 variants and by immunofluorescence with stably transfected CHO cell lines expressing SP-A1 or SP-A2 variants. SP-A1 content was evaluated according to age and lung status. A gradual decrease (P < 0.05) in SP-A1/SP-A ratio was observed in healthy subjects (HS) with increased age, although no significant change was observed in total SP-A content among age groups. Total SP-A and SP-A1 content differed significantly between alveolar proteinosis (AP) patients and HS, with no significant difference observed in SP-A1/SP-A ratio between AP and HS. The cystic fibrosis (CF) ratio was significantly higher compared with AP, HS, and noncystic fibrosis (NCF), even though SP-A1 and total SP-A were decreased in CF compared with most of the other groups. The ratio was higher in culture-positive vs. culture-negative samples from CF and NCF (P = 0.031). A trend of an increased ratio was observed in culture-positive CF (0.590 +/- 0.10) compared with culture-positive NCF (0.368 +/- 0.085). In summary, we developed and characterized an SP-A1 gene-specific antibody and used it to identify gene-specific SP-A content in BALFs as a function of age and lung health.
authors.affiliation: Departments of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA.
authors.forename: Hephzibah Rani S
authors.initials: HR
authors.lastname: Tagaram
authors.forename: Guirong
authors.initials: G
authors.lastname: Wang
authors.forename: Todd M
authors.initials: TM
authors.lastname: Umstead
authors.forename: Anatoly N
authors.initials: AN
authors.lastname: Mikerov
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Thomas
authors.forename: Gavin R
authors.initials: GR
authors.lastname: Graff
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Hess
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Thomassen
authors.forename: Mani S
authors.initials: MS
authors.lastname: Kavuru
authors.forename: David S
authors.initials: DS
authors.lastname: Phelps
authors.forename: Joanna
authors.initials: J
authors.lastname: Floros
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D018893:Bronchoalveolar Lavage; D016466:CHO Cells; D002648:Child; D006224:Cricetinae; D003412:Cricetulus; D003550:Cystic Fibrosis / Q000503:physiopathology*; D014644:Genetic Variation; D006801:Humans; D008168:Lung / Q000502:physiology* / Q000503:physiopathology; D037662:Pulmonary Surfactant-Associated Protein A / Q000235:genetics* / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D037662:Pulmonary Surfactant-Associated Protein A; C445842:SFTPA1 protein, human