Roles of T lymphocytes in pulmonary fibrosis.
Infiltration of T lymphocytes in the lungs is common in patients with and in animal models of pulmonary fibrosis. The role of these cells in regulating the accumulation of extracellular matrix, particularly collagen, is not understood completely. Research literature provides evidence for a profibrotic, an antifibrotic, or no significant role of T lymphocytes in pulmonary fibrosis. This review offers a discussion of such evidence with the focus on phenotypes of pulmonary T lymphocytes and related profibrotic and antifibrotic mechanisms. It appears unlikely that T lymphocytic infiltration per se is the central driving force in most cases of pulmonary fibrosis. Instead, evidence suggests that T lymphocytes may modulate the inflammatory and healing responses in the lungs in a profibrotic or antifibrotic manner, depending on their phenotype. Phenotypic reshaping, rather than elimination of the infiltrating pulmonary T lymphocytes, may be a promising approach to improving outcomes in patients with pulmonary fibrosis.
Luzina
Irina G
IG
University of Maryland School of Medicine and Baltimore VA Medical Center, Baltimore, MD 21201, USA.
Todd
Nevins W
NW
Iacono
Aldo T
AT
Atamas
Sergei P
SP
D000818:Animals; D018106:CD28 Antigens / Q000235:genetics; D003240:Connective Tissue Diseases / Q000150:complications; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D007249:Inflammation; D017563:Lung Diseases, Interstitial / Q000473:pathology / Q000503:physiopathology; D008212:Lymphocyte Depletion; D008222:Lymphokines / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008819:Mice, Nude; D016513:Mice, SCID; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000502:physiology*
D018106:CD28 Antigens; D008222:Lymphokines