Biomarkers for Comorbidities Modulate the Activity of T-Cells in COPD.

In smoking-induced chronic obstructive pulmonary disease (COPD), various comorbidities are linked to systemic inflammation and infection-induced exacerbations. The underlying mechanisms are unclear but might provide therapeutic targets. T-cell activity is central in systemic inflammation and for infection-defense mechanisms and might be influenced by comorbidities. Hypothesis: Circulating biomarkers of comorbidities modulate the activity of T-cells of the T-helper type 1 (Th1) and/or T-cytotoxic type 1 (Tc1). T-cells in peripheral blood mononuclear cells (PBMCs) from non-smokers (NS), current smokers without COPD (S), and COPD subjects (total n = 34) were ex vivo activated towards Th1/Tc1 and were then stimulated with biomarkers for metabolic and/or cardiovascular comorbidities (Brain Natriuretic Peptide, BNP; chemokine (C-C motif) ligand 18, CCL18; C-X3-C motif chemokine ligand 1, CX3CL1; interleukin-18, IL-18) or for asthma- and/or cancer-related comorbidities (CCL22; epidermal growth factor, EGF; IL-17; periostin) each at 10 or 50 ng/mL. The Th1/Tc1 activation markers interferon-γ (IFNγ), tumor necrosis factor-α (TNFα), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were analyzed in culture supernatants by Enzyme-Linked Immunosorbent Assay (ELISA). Ex-vivo activation induced IFNγ and TNFα without differences between the groups but GM-CSF more in S vs. NS. At 10 ng/mL, the different biomarkers increased or reduced the T-cell activation markers without a clear trend for one direction in the different categories of comorbidities or for the different T-cell activation markers. At 50 ng/mL, there was a clear shift towards suppressive effects, particularly for the asthma- and cancer-related biomarkers and in cells of S and COPD. Comorbidities might suppress T-cell immunity in COPD. This could explain the association of comorbidities with frequent exacerbations.

Simvastatin requires activation in accessory cells to modulate T-cell responses in asthma and COPD.

T-cell-dependent airway and systemic inflammation triggers the progression of chronic obstructive pulmonary disease (COPD) and asthma. Retrospective studies suggest that simvastatin has anti-inflammatory effects in both diseases but it is unclear, which cell types are targeted. We hypothesized that simvastatin modulates T-cell activity. Circulating CD4+ and CD8+ T-cells, either pure, co-cultured with monocytes or alveolar macrophages (AM) or in peripheral blood mononuclear cells (PBMCs), were ex vivo activated towards Th1/Tc1 or Th2/Tc2 and incubated with simvastatin. Markers for Th1/Tc1 (IFNγ) and Th2/Tc2 (IL-5, IL-13) were measured by ELISA; with PBMCs this was done comparative between 11 healthy never-smokers, 11 current smokers without airflow limitation, 14 smokers with COPD and 11 never-smokers with atopic asthma. T-cell activation induced IFNγ, IL-5 and IL-13 in the presence and absence of accessory cells. Simvastatin did not modulate cytokine expression in pure T-cell fractions. ß-hydroxy-simvastatin acid (activated simvastatin) suppressed IL-5 and IL-13 in pure Th2- and Tc2-cells. Simvastatin suppressed IL-5 and IL-13 in Th2-cells co-cultivated with monocytes or AM, which was partially reversed by the carboxylesterase inhibitor benzil. Simvastatin suppressed IL-5 production of Th2/Tc2-cells in PBMCs without differences between cohorts and IL-13 stronger in never-smokers and asthma compared to COPD. Simvastatin induced IFNγ in Th1/Tc1-cells in PBMCs of all cohorts except asthmatics. Simvastatin requires activation in accessory cells likely by carboxylesterase to suppress IL-5 and IL-13 in Th2/Tc2-cells. The effects on Il-13 are partially reduced in COPD. Asthma pathogenesis prevents simvastatin-induced IFNγ up-regulation. Simvastatin has anti-inflammatory effects that could be of interest for asthma therapy.