A comparative proteomic approach was applied to examine nasal lavage fluid (NLF) from patients with
seasonal allergic rhinitis (SAR, n = 6) and healthy subjects (controls, n = 5). NLF samples were taken both before
allergy (pollen) season and during season, and
proteins were analyzed by two-dimensional gel electrophoresis (2-DE) and matrix assisted
laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) after tryptic cleavage. Twenty
proteins were selected and quantified. During
allergy season, the levels of six sialylated
isoforms of PLUNC (palate lung nasal epithelial clone) were lower in SAR patients than controls, as were the levels of six
isoforms of
von Ebner's gland protein (VEGP), including a previously undescribed form with N-linked glycosylation, and of
cystatin S. PLUNC is a new innate immunity
protein and VEGP and
cystatin S are two endogenous
proteinase inhibitors. By contrast, the levels of an acidic form of alpha-1-antitrypsin were higher in SAR patients than controls. One previously unidentified NLF
protein was found in all samples from the SAR patients during
allergy season but not in any sample before
allergy season: this
protein was identified as
eosinophil lysophospholipase (
Charcot-Leyden crystal protein/galactin 10). MS/MS analysis of the N-terminus of the
protein showed removal of Met and acetylation of Ser. Altogether, these findings illustrate the potential use of proteomics for identifying
protein changes associated with
allergic rhinitis and for revealing post-translational modifications of such new potential markers of allergic
inflammation.