Roles of T lymphocytes in pulmonary fibrosis

J Leukoc Biol. 2008 Feb;83(2):237-44. doi: 10.1189/jlb.0707504. Epub 2007 Oct 25.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • CD28 Antigens / genetics
  • Connective Tissue Diseases / complications
  • Disease Models, Animal
  • Extracellular Matrix / metabolism
  • Humans
  • Inflammation
  • Lung Diseases, Interstitial / pathology
  • Lung Diseases, Interstitial / physiopathology
  • Lymphocyte Depletion
  • Lymphokines / metabolism
  • Mice
  • Mice, Knockout
  • Mice, Nude
  • Mice, SCID
  • Pulmonary Fibrosis / etiology
  • Pulmonary Fibrosis / immunology
  • Pulmonary Fibrosis / pathology*
  • Pulmonary Fibrosis / physiopathology
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / physiology*


  • CD28 Antigens
  • Lymphokines