T cell subsets in human airways prior to and following endobronchial administration of endotoxin.

Abstract

BACKGROUND AND OBJECTIVES:

Bronchial instillation of lipopolysaccharide (LPS) provides a reversible model of lung inflammation that may resemble early stages of acute respiratory distress syndrome (ARDS). We investigated the distributions of T-cell subsets in the human airways and sought to determine whether pro- and anti-inflammatory T cells are involved in the local immune response to lung inflammation.

METHODS:

Bronchoalveolar lavage (BAL) was performed in 15 healthy volunteers, after which Escherichia coli LPS (4 ng/kg) was administered. BAL was repeated at 2, 4, 6, 8 or 24 h after instillation of LPS.

RESULTS:

BALF CD4+ and CD8+ T cells were characterized by expression of activation markers (HLA-DR+CD38+), the proportion of cells expressing naïve markers (CD45RA+CD27+CCR7+) was lower, and that of cells expressing effector memory markers (CD45RA-CD27+CCR7-) was higher, compared with peripheral blood. Bronchial LPS induced a local inflammatory response with recruitment of CD4+ (P=0.014), CD8+ T cells (P=0.034), an increase in the proportion of CD4+CD25+CD127lowFoxp3+ regulatory T cells (Tregs) (P=0.045) and a tendency towards an increase in CD4+CD161+ cells (P=0.071) were observed.

CONCLUSIONS:

A unique distribution of T cells with little day-to-day variation was found in human airways. An increase in Tregs after endobronchial LPS suggests a role for Tregs during early stages of pulmonary inflammation.

• Authors: Andreas Ronit, Ronni R Plovsing, Julie C Gaardbo, Ronan M G Berg, Hans J Hartling, Lars Konge, Martin Iversen, Henrik Ullum, Kirsten Møller, Susanne Dam Nielsen
• Journal: Respirology (Carlton, Vic.) (Respirology) Vol. 20 Issue 4 Pg. 579-86 (May 2015) ISSN: 1440-1843 [Electronic] Australia
• PMID: 25711164 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 Asian Pacific Society of Respirology.

Chemical References

• Endotoxins
• Lipopolysaccharides

Topics

• Bronchoalveolar Lavage Fluid (cytology)
• CD4 Lymphocyte Count
• CD4-Positive T-Lymphocytes (immunology)
• Endotoxins
• Flow Cytometry
• Humans
• Lipopolysaccharides (poisoning)
• Lymphocyte Count
• Male
• Pneumonia (chemically induced, immunology)
• Respiratory Distress Syndrome (immunology)
• T-Lymphocyte Subsets (immunology)
• T-Lymphocytes, Regulatory (immunology)
• Young Adult