Role of PLUNC in diabetes and oral disease

Objectives: Palate, lung, and nasal epithelium clone protein (PLUNC) is a secreted protein in saliva, upper respiratory tract, and lung. PLUNC is known to associated with several oral conditions including diabetes and periodontitis.

Methods: Using computational and proteomic methods, we define the structural domain of PLUNC and propose how PLUNC may function in saliva. Using mass spectrometry proteomics, we compared (1) the salivary proteomes from patients with diabetes and non-diabetic patients; and (1) the salivary proteomes from HIV patients with and without oral candidiasis. Multidimensional liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) was used. Cluster analysis and principle component analysis were used to define the protein biomarkers.

Results: PLUNC appears to have a globular structure similar to bactericidal/permeability-increasing proteins (BPI) and lipopolysaccharide-binding proteins (LBP). The N-terminal portion of PLUNC is unstructured. Mass spectrometry proteomics suggest that PLUNC is among the most prominent biomarkers found associated with diabetes and oral candidiasis associated with HIV-infection.

Conclusions: PLUNC plays an important role in oral immunity. PLUNC may prevent oral infection in patients with  diabetes and prevent candidal opportunistic infection in HIV-infected patients.