Enhanced Frequency but Preserved Th1/Tc1 Responses of Rhinovirus-Specific T Cells in COPD

Viral infections, particularly by rhinoviruses (RVs), represent major triggers of acute exacerbations in chronic obstructive pulmonary disease (COPD). However, the role of RV-specific T cell responses in COPD remains poorly characterized. Here, we investigated T cell recall responses to conserved RV-specific T cell epitopes in COPD patients and age-matched healthy controls using activation-induced marker and intracellular cytokine staining assays. The frequency of RV-specific CD4⁺ T cells was increased in COPD patients compared with healthy participants. RV-specific CD8⁺ T cells also tended to be increased in COPD participants, although the differences did not reach statistical significance. Functional T cell responses to RV-specific epitopes were biased toward IFN-γ and TNF-α production in COPD and healthy participants, with no significant differences between groups. Accordingly, there is a degree of functional dissociation between enhanced RV-specific CD4⁺ T cell recognition and cytokine responses in COPD. A modest inverse correlation, yet not statistically significant (p = 0.066), was observed between IFN-γ-producing CD4⁺ T cells and disease severity, as assessed by FEV₁. Collectively, our findings suggest that T cell responses to conserved RV-specific epitopes are unlikely to be major drivers of COPD immunopathology, supporting their potential relevance for epitope-vaccine development in COPD.