umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Expansion of helper T cells with a non-regulatory function in smoking and COPD
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine. (Lungmedicin)
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine. (Lungmedicin)
Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine. (Lungmedicin)
Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå, Sweden. (Lungmedicin)
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Regulatory T cells have been implicated in the pathogenesis of COPD by the increased expression of CD25 on helper T cells. Regulatory CD4+ T cells are reported to have increased intracellular expression of FoxP3 and low/absent CD127 expression on the cell surface. Here, these markers were investigated in BALF from nine COPD subjects and compared to fourteen smokers with normal lung function and nine never-smokers.

In smokers with normal lung function, the expression of CD25 on CD4+ lymphocytes was increased, whereas the proportions of FoxP3+ and CD127+ were unchanged compared to never-smokers. Among the population of helper T cells expressing high levels of CD25, the proportion FoxP3+ cells was decreased and the percentage CD127+ was increased in smokers with normal lung function. CD25+ helper T cells with low/absent CD127 expression were increased in smokers with normal lung function, but not in COPD, when compared to never smokers. In COPD, a decrease in CD127 expression on CD4+CD25+ was observed in ex-smokers compared to current smokers.

Smoking induces the expansion of activated airway helper T cells that seem to persist after COPD development. The reduction of FoxP3 expression indicates that the increase in CD25 expression is not only associated with the expansion of regulatory T cells. Instead, the high CD127 and low FoxP3 expressions implicate a predominantly non-regulatory CD25+ helper T cell population in stable COPD. In some smokers with normal lung function, we identified a helper T cell population with a putative regulatory function, which may be protective against COPD development.

National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
URN: urn:nbn:se:umu:diva-33670OAI: oai:DiVA.org:umu-33670DiVA: diva2:317113
Available from: 2010-05-03 Created: 2010-05-03 Last updated: 2010-05-15Bibliographically approved
In thesis
1. T cells in chronic obstructive pulmonary disease
Open this publication in new window or tab >>T cells in chronic obstructive pulmonary disease
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background: Tobacco smoking is the main cause of chronic obstructive pulmonary disease, COPD, but the mechanisms by which cigarette smoke induces COPD are still elusive. T lymphocytes have been implicated in the pathogenesis of the disease, but their role in the airway inflammation in COPD is not fully understood. The aim of this thesis was therefore to address T lymphocyte subsets and their activation in the airways of subjects with COPD, in comparison to smokers with normal lung function (S) and never smokers (NS).

Methods: Subjects with moderate to severe COPD were recruited along with controls. They were all non-atopic and clinically stable, without any exacerbation during at least three months prior to inclusion. Only medication with short-acting β2-agonists and/or anti-cholinergic drugs was permitted. All subjects underwent bronchoscopy with endobronchial mucosal biopsy sampling as well as bronchial wash, BW, and bronchoalveolar lavage, BAL, collection. Biopsies were immunohistochemically stained for inflammatory cells and markers. BW and BAL fluids were prepared for differential cell counts. Soluble markers were measured in BW and lymphocyte subsets were determined in BAL using flow cytometry.

Results: In biopsies, an increase in epithelial CD3+ and CD8+ cells was found in COPD, compared to NS. In BAL fluid, CD8+ cells were enhanced, whereas CD4+ cells were reduced in subjects with COPD and S, compared to NS. Furthermore, CD4+ and CD8+ cells were more activated both in COPD and S, in terms of increased expression of CD25, CD69 and HLA-DR. NKG2D-expressing CD8+ T cells in BAL fluid were enhanced in both COPD and S. CD4+CD25bright cells were upregulated in COPD and S, suggesting the presence of regulatory T cells. Further analyses of T cell subsets with the more specific markers for regulatory T cells, FoxP3 and CD127, indicated a smoking-induced expansion of non-regulatory T cells, which tended to normalize after smoking cessation in COPD. Currently smoking subjects with COPD still expressed high proportions of activated non-regulatory CD4+ T cells. The data on FoxP3 expression further indicated that the increase in CD25 expression in COPD and S was not only associated with the expansion of regulatory T cells. As CD127 expression is reported to be inversely associated with FoxP3, the data indicate the expansion of a non-regulatory CD25+ population in smokers and patients with stable COPD. The immunohistochemical staining for the NKG2D ligands MICA and MICB on epithelial cells was unchanged.

Conclusion: The results of this thesis suggest a role for CD4+ and CD8+ T-cells in clinically stable COPD, indicating that T-cells are of importance in the long-term inflammatory response in COPD. Regardless of current smoking habits, activated CD8+ T lymphocytes were found to be increased in BAL fluid from subjects with COPD, suggesting that changes in CD8+ T cells are associated with a persistent immune response and, thus, of importance in COPD pathogenesis. In contrast, the expansion of non-regulatory CD25+CD4+ cells in BAL fluid seemed to be preferentially smoke-related. In summary, the data indicate that, among airway T cells, changes in CD8+ cells seem to be highly associated with COPD pathogenesis, whereas changes in CD4+ cells appear to be related to cigarette smoke-induced responses. Further, a non regulatory population of helper T cells was identified in BAL fluid of COPD patients, which may contribute to the persistent cytotoxic T cell responses.

Place, publisher, year, edition, pages
Umeå: Umeå university, 2010. 86 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1331
Keyword
airway epithelium, bronchoscopy, bronchoalveolar lavage, endobronchial mucosal biopsies, inflammation, flow cytometry, T lymphocytes, CD25, CD127, FoxP3
National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
urn:nbn:se:umu:diva-33677 (URN)978-91-7264-952-1 (ISBN)
Public defence
2010-06-04, Betula, Byggnad 6M, NUS, Umeå, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2010-05-15 Created: 2010-05-03 Last updated: 2010-08-26Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Roos-Engstrand, EsterPourazar, JamshidBehndig, Annelie FBlomberg, Anders

Search in DiVA

By author/editor
Roos-Engstrand, EsterPourazar, JamshidBehndig, Annelie FBlomberg, Anders
By organisation
Pulmonary Medicine
Respiratory Medicine and Allergy

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 86 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf