title: Expression sites of the collectin SP-D suggest its importance in first line host defence: power of combining in situ hybridisation, RT-PCR and immunohistochemistry.
abstract: Surfactant proteins A and D are pattern recognition molecules that play a role in pulmonary host defence. In this paper, we describe for the first time the expression and localisation of both collectins in various porcine tissues using a combination of in situ hybridisation (ISH), RT-PCR and immunohistochemistry (IHC). SP-D was expressed in several tissues including lung, tongue, intestinal tract, thymus, skin, gall bladder and lacrimal gland. Focal SP-D expression was detected in oesophagus, stomach, kidney, liver, prostate and spleen with both histological techniques. These tissues tested negative with RT-PCR. In contrast, SP-A expression was limited to the lung as measured by ISH and IHC. Interestingly, analysis by RT-PCR showed that thymus, trachea, jejunum and duodenum are positive for the presence of SP-A mRNA. We conclude that the combination of different methods can be advantageous if tissue-specific expression is studied. The importance of SP-D in innate immune defence of the pig is underlined by its expression at the potential ports of entry of pathogens.
authors.affiliation: Department of Infectious Diseases and Immunology, Division Molecular Host Defence, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80175, NL-3508 TD Utrecht, The Netherlands.
authors.forename: M Veronica
authors.initials: MV
authors.lastname: Herías
authors.forename: Astrid
authors.initials: A
authors.lastname: Hogenkamp
authors.forename: Alphons J A M
authors.initials: AJ
authors.lastname: van Asten
authors.forename: Monique H G
authors.initials: MH
authors.lastname: Tersteeg
authors.forename: Martin
authors.initials: M
authors.lastname: van Eijk
authors.forename: Henk P
authors.initials: HP
authors.lastname: Haagsman
mesh_terms: D000818:Animals; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D037662:Pulmonary Surfactant-Associated Protein A / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D037663:Pulmonary Surfactant-Associated Protein D / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D014018:Tissue Distribution / Q000235:genetics / Q000276:immunology
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D012333:RNA, Messenger