Increased T-regulatory cells in lungs and draining lymph nodes in a murine model of COPD: Fig. 1—

Abstract

To the Editors: The characterisation of regulatory T (Treg) cells in chronic obstructive pulmonary disease (COPD) has become of particular interest considering the recent reports on adaptive immune responses in COPD. More specifically, peribronchial and parenchymal lymphoid follicles ( i.e. tertiary lymphoid organs) correlate in number with disease severity in COPD patients 1 and murine models of COPD 2, but their developing mechanisms and function have yet to be revealed 3. In COPD patients, pulmonary lymphoid follicles mainly appear as a B-cell core surrounded by a predominant cluster of differentiation (CD)4+ T-cell population 3. Treg cells situated within these structures are ideally located to exert cell contact-dependent immunosuppression. The observation on increased Treg cells in lymphoid follicles of moderate COPD patients by Plumb et al. 4, is therefore particularly intriguing. The different reports on Treg cells in COPD vary greatly, depending on the pulmonary anatomical compartment of interest and the phenotype used to define …