LPS challenge in healthy subjects: An investigation of neutrophil chemotaxis mechanisms involving CXCR1 and CXCR2

• Published in: International immunopharmacology Vol. 13; no. 3; pp. 225 - 231
• Main Authors: Aul, Raminder, Patel, Sheena, Summerhill, Susan, Kilty, Iain, Plumb, Jonathan, Singh, Dave
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.07.2012; Elsevier
• Subjects: Administration, Inhalation; Adult; Benzamides - pharmacology; Biological and medical sciences; Chemokine CCL2 - metabolism; Chemotaxis; Chemotaxis, Leukocyte - drug effects; Chemotaxis, Leukocyte - immunology; Chronic obstructive pulmonary disease, asthma; COPD; CXCR1; CXCR2; Cyclobutanes - pharmacology; Female; Humans; Interleukin-6 - metabolism; Leukocyte Count; Lipopolysaccharide; Lipopolysaccharides - administration & dosage; Male; Medical sciences; Models, Immunological; Neutrophils; Neutrophils - drug effects; Neutrophils - immunology; Pharmacology. Drug treatments; Phenylurea Compounds - pharmacology; Pneumology; Receptors, Interleukin-8A - antagonists & inhibitors; Receptors, Interleukin-8A - metabolism; Receptors, Interleukin-8B - antagonists & inhibitors; Receptors, Interleukin-8B - metabolism; Sputum - cytology; Sputum - immunology; Sulfonamides - pharmacology; Lipopolysaccharide; CXCR1; Chemotaxis; Neutrophils; CXCR2; COPD; Human; Lung disease; Healthy subject; Respiratory disease; Granulocyte; Chemokine receptor; CXCR2 chemokine receptor; Bronchus disease; Obstructive pulmonary disease; Neutrophil; CXC chemokine; Mechanism of action; CXCR1 chemokine receptor
• ISSN: 1567-5769; 1878-1705; 1878-1705
• DOI: 10.1016/j.intimp.2012.04.008

LPS inhalation was used to investigate whether sputum supernatant post-LPS challenge increases neutrophil chemotactic activity and to elucidate the role of CXCR1/CXCR2 signalling in this process. 14 healthy non-smoking subjects inhaled 30μg of LPS. Sputum was induced at baseline, 6 and 24h post-LPS challenge. Differential cell counts were determined and supernatants CXCL8, CXCL1, IL-6 and CCL2 levels measured. Peripheral blood neutrophils obtained from healthy volunteers were used for chemotaxis experiments using sputum supernatant. To delineate signalling mechanisms, the effects of a CXCR2/CXCR1 (dual) antagonist (Sch527123) and a CXCR2 specific antagonist (SB656933) were tested. LPS inhalation significantly increased sputum neutrophil counts from 45.3% to 76.7% and 69.3% at 6 and 24h respectively. LPS increased CXCL8, IL-6 and CCL2 levels but not CXCL1. Neutrophil chemotaxis significantly increased (2.7 fold) at 24h compared to baseline. Chemotaxis was inhibited by 79.0% with Sch527123 and 52.0% with SB656933. We conclude that LPS challenge increases sputum supernatant CXCL8 levels, which is associated with increased chemotactic activity which is dependent on both CXCR1 and CXCR2. ► LPS inhalation in healthy subjects increases the levels of CXCL8 but not CXCL1. ► LPS inhalation also increases the chemotactic capacity of sputum supernatant. ► Chemotactic capacity inhibited more using a dual CXCR1/CXCR2 antagonist. ► TLR4 signalling causes airway neutrophilia dependent on CXCL8 driven chemotaxis. ► Supports development of dual CXC1/CXCR2 antagonists for neutrophilic lung diseases