Purification of surfactant protein D (SP-D) from pooled amniotic fluid and bronchoalveolar lavage.
Surfactant protein SP-D is a multimeric collagenous lectin, called collectin. SP-D is a multifunctional, pattern recognition innate immune molecule, which binds in a calcium dependent manner to an array of carbohydrates and lipids, thus offering resistance to invading pathogens, allergen challenge, and pulmonary inflammation. SP-D is predominantly found in the endoplasmic reticulum of type 2 pneumocytes and in the secretory granules of Clara or non-ciliated bronchiolar cells. The highest expression of SP-D is observed in the distal airways and alveoli. There is also an extra pulmonary existence of SP-D. The common sources of native full-length human SP-D are bronchoalveolar lavage (BAL) washings from normal or preferably patients suffering from alveolar proteinosis who overproduce SP-D in the lungs. Amniotic fluid collected at the term during parturition is another reasonable source. Here, we describe a simple and rapid method of purifying native SP-D away from SP-A which is also present in the same source. We also describe procedures of expressing and purifying a recombinant fragment of human SP-D (rhSP-D) comprising trimeric neck and carbohydrate recognition domains that has been shown to have therapeutic effects in murine models of allergy and infection.
Centre for Infection, Immunity and Disease Mechanisms, Biosciences, School of Health Sciences and Social Care, Brunel University, London, UK.
Eswari
E
Dodagatta-Marri
Asif S
AS
Qaseem
Najmunisa
N
Karbani
Anthony G
AG
Tsolaki
Patrick
P
Waters
Taruna
T
Madan
Uday
U
Kishore
D000653:Amniotic Fluid / Q000737:chemistry*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002846:Chromatography, Affinity / Q000379:methods; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D037663:Pulmonary Surfactant-Associated Protein D / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification
D037663:Pulmonary Surfactant-Associated Protein D; D011994:Recombinant Proteins