Characterization of immunoglobulin binding factor in sputum from patients with chronic airway diseases

Neutrophil elastase in bronchiectasis

The role of neutrophil elastase (NE) is poorly understood in bronchiectasis because of the lack of preclinical data and so most of the assumptions made about NE inhibitor potential benefit is based on data from CF. In this context, NE seems to be a predictor of long-term clinical outcomes and a possible target of treatment. In order to better evaluate the role of NE in bronchiectasis, a systematic search of scientific evidence was performed.Two investigators independently performed the search on PubMed and included studies published up to May 15, 2017 according to predefined criteria. A final pool of 31 studies was included in the systematic review, with a total of 2679 patients. For each paper data of interest were extracted and reported in table.In this review sputum NE has proved useful as an inflammatory marker both in stable state bronchiectasis and during exacerbations and local or systemic antibiotic treatment. NE has also been associated with risk of exacerbation, time to next exacerbation and all-cause mortality. This study reviews also the role of NE as a specific target of treatment in bronchiectasis. Inhibition of NE is at a very early stage and future interventional studies should evaluate safety and efficacy for new molecules and formulations.

Identification of lipocalin and apolipoprotein A1 as biomarkers of chronic obstructive pulmonary disease

RATIONALE

Much effort is being made to discover noninvasive biomarkers of chronic airway disease that might enable better management, predict prognosis, and provide new therapeutic targets.

OBJECTIVES

To undertake a comprehensive, unbiased proteomic analysis of induced sputum and identify novel noninvasive biomarkers for chronic obstructive pulmonary disease (COPD).

METHODS

Induced sputum was obtained from patients with COPD with a spectrum of disease severity and from control subjects. Two-dimensional gel electrophoresis and mass spectrometric identification of differentially expressed proteins were first applied to induced sputum from patients with GOLD stage 2 COPD and healthy smoker control subjects. Initial results thus obtained were validated by a combination of immunoassays (Western blotting and ELISA) applied to a large subject cohort. The biomarkers were localized to bronchial mucosa by immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

Of 1,325 individual protein spots identified, 37 were quantitatively and 3 qualitatively different between the two groups (P < 0.05%). Forty protein spots were subjected to tandem mass spectrometry, which identified 15 separate protein species. Seven of these were further quantified in induced sputum from 97 individuals. Using this sequential approach, two of these potential biomarkers (apolipoprotein A1 and lipocalin-1) were found to be significantly reduced in patients with COPD when compared with healthy smokers. Their levels correlated with FEV(1)/FVC, indicating their relationship to disease severity.

CONCLUSIONS

A potential role for apolipoprotein A1 and lipocalin-1 in innate defense has been postulated previously; our discovery of their reduction in COPD indicates a deficient innate defense system in airway disease that could explain increased susceptibility to infectious exacerbations.

Human seminal plasma antibody-binding proteins

PROBLEM

The physiological role of antibody-binding proteins in human seminal plasma and the potential role of these proteins in infertility is relatively unknown.

METHOD OF STUDY

Literature on antibody-binding proteins.

RESULTS

Human seminal plasma has a diverse effect on immune function of the reproductive tracts. This review describes (1) the presence of receptors like proteins that can react with monoclonal antibodies against Fcgamma receptors III (Fcgamma RIII) but are distinctly different from Fcgamma RIII; (2) IgG binding factors (IgGBF), a group of low molecular weight proteins that are capable of binding human IgG; (3) other proteins that can bind antibodies, such as prolactin-inducible protein and three other novel proteins that we have discovered. These proteins potentially all have the ability to reduce the interactions between antisperm antibodies and effector components of the immune system, such as phagocytic cells.

CONCLUSIONS

Human seminal plasma contains proteins that can bind antibodies. However, to date our knowledge of these proteins especially, whether they have a physiological role in either the male and female reproductive tracts is limited.

Antibody-binding proteins in human seminal plasma

PROBLEM

The significance of antibody-mediated infertility is unclear and complicated by the finding of that antisperm antibodies are found both in fertile and infertile couples. Seminal plasma contains immunosuppressive factors, one such factor may be antibody-binding proteins (ABP's).

METHOD OF STUDY

Antibody-binding-proteins were purified using human IgG or IgG-Fc affinity chromatography columns. The purified antibody-binding proteins were characterized by their molecular weights, partial amino acid sequences, and immunoreactivities.

RESULTS

Three proteins of molecular weight 74, 70 and 55 kDa and other low molecular weight proteins specifically bound to the IgG or IgG-Fc affinity columns demonstrating Fc-binding specificities. These proteins were not FcgammaRIII, IgG, or fragments of these proteins by their behaviors under reducing conditions, Western blot, and partial amino acid sequence analyses. Amino acid sequence data demonstrated some of these proteins to be novel.

CONCLUSIONS

We have isolated and partially characterized several ABP's from seminal plasma. The IgG-binding proteins we have identified may protect spermatozoa against antibody-mediated damage by conferring protection to antibody-coated spermatozoa. If this hypothesis holds true, differences in the level or function of these ABP's may alter the status of fertility.

Database of bronchoalveolar lavage fluid proteins

Bronchoalveolar lavage during fiberoptic bronchoscopy is extensively used for investigating cellular and biochemical alterations of the epithelial lining fluid in various lung disorders. Two-dimensional electrophoresis (2-DE) offers the possibility to simultaneously display and analyze proteins contained in bronchoalveolar lavage fluid (BALF). We present the current status of 2-DE of BALF samples with an updated listing of the proteins already identified and of their level and/or posttranslational alterations in lung disorders. Alternatives to 2-DE of BALF samples and future prospects of proteomics to unravel lung functions and pathologies are discussed.