Local Defence System in Healthy Lungs

• Published in: Clinics and practice Vol. 11; no. 4; pp. 728 - 746
• Main Authors: Lohova, Elizabeta, Vitenberga-Verza, Zane, Kazoka, Dzintra, Pilmane, Mara
• Format: Journal Article
• Language: English
• Published: Bari MDPI AG 01.10.2021; MDPI
• Subjects: Antimicrobial agents; Bacteria; Cell adhesion & migration; Chemokines; Cooperation; Cytokines; Defense; factors; Gene expression; Gram-negative bacteria; Gram-positive bacteria; healthy lungs; immunity; Infections; Inflammation; Kinases; local defence; Lungs; Lymphocytes; Neutrophils; Pathogens; Peptides; Respiratory system; Surfactants; Tumor necrosis factor-TNF; Latvia
• ISSN: 2039-7283; 2039-7275; 2039-7283
• DOI: 10.3390/clinpract11040088

Background: The respiratory system is one of the main entrance gates for infection. The aim of this work was to compare the appearance of specific mucosal pro-inflammatory and common anti-microbial defence factors in healthy lung tissue, from an ontogenetic point of view. Materials and methods: Healthy lung tissues were collected from 15 patients (three females and 12 males) in the age range from 18 to 86. Immunohistochemistry to human β defensin 2 (HBD-2), human β defensin 3 (HBD-3), human β defensin 4 (HBD-4), cathelicidine (LL-37) and interleukine 17A (IL-17A) were performed. Results: The lung tissue material contained bronchial and lung parenchyma material in which no histological changes, connected with the inflammatory process, were detected. During the study, various statistically significant differences were detected in immunoreactive expression between different factors in all lung tissue structures. Conclusion: All healthy lung structures, but especially the cartilage, alveolar epithelium and the alveolar macrophages, are the main locations for the baseline synthesis of antimicrobial proteins and IL-17A. Cartilage shows high functional plasticity of this structure, including significant antimicrobial activity and participation in local lung protection response. Interrelated changes between antimicrobial proteins in different tissue confirm baseline synergistical cooperation of all these factors in healthy lung host defence.