Formation of Calprotectin-Derived Peptides in the Airways of Children with Cystic Fibrosis.
J Immunol
; 208(4): 979-990, 2022 02 15.
Article
in English
| MEDLINE | ID: covidwho-1631932
ABSTRACT
Calprotectin is released by activated neutrophils along with myeloperoxidase (MPO) and proteases. It plays numerous roles in inflammation and infection, and is used as an inflammatory biomarker. However, calprotectin is readily oxidized by MPO-derived hypohalous acids to form covalent dimers of its S100A8 and S100A9 subunits. The dimers are susceptible to degradation by proteases. We show that detection of human calprotectin by ELISA declines markedly because of its oxidation by hypochlorous acid and subsequent degradation. Also, proteolysis liberates specific peptides from oxidized calprotectin that is present at inflammatory sites. We identified six calprotectin-derived peptides by mass spectrometry and detected them in the bronchoalveolar lavage fluid of children with cystic fibrosis (CF). We assessed the peptides as biomarkers of neutrophilic inflammation and infection. The content of the calprotectin peptide ILVI was related to calprotectin (r = 0.72, p = 0.01, n = 10). Four of the peptides were correlated with the concentration of MPO (r > 0.7, p ≤ 0.01, n = 21), while three were higher (p < 0.05) in neutrophil elastase-positive (n = 14) than -negative samples (n = 7). Also, five of the peptides were higher (p < 0.05) in the bronchoalveolar lavage fluid from children with CF with infections (n = 21) than from non-CF children without infections (n = 6). The specific peptides liberated from calprotectin will signal uncontrolled activity of proteases and MPO during inflammation. They may prove useful in tracking inflammation in respiratory diseases dominated by neutrophils, including coronavirus disease 2019.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Peptides
/
Respiratory System
/
Bronchoalveolar Lavage Fluid
/
Cystic Fibrosis
/
Leukocyte L1 Antigen Complex
/
Inflammation
/
Neutrophils
Type of study:
Diagnostic study
Limits:
Child
/
Child, preschool
/
Female
/
Humans
/
Male
Language:
English
Journal:
J Immunol
Year:
2022
Document Type:
Article
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