Expansion of helper T cells with a non-regulatory function in smoking and COPD
(English)Manuscript (preprint) (Other academic)
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.
Respiratory Medicine and Allergy
Research subject Lung Medicine
IdentifiersURN: urn:nbn:se:umu:diva-33670OAI: oai:DiVA.org:umu-33670DiVA: diva2:317113