Role of inducible bronchus associated lymphoid tissue (iBALT) in respiratory immunity

Nat Med. 2004 Sep;10(9):927-34. doi: 10.1038/nm1091. Epub 2004 Aug 15.


Bronchus-associated lymphoid tissue (BALT) is occasionally found in the lungs of mice and humans; however, its role in respiratory immunity is unknown. Here we show that mice lacking spleen, lymph nodes and Peyer's patches generate unexpectedly robust primary B- and T-cell responses to influenza, which seem to be initiated at sites of induced BALT (iBALT). Areas of iBALT have distinct B-cell follicles and T-cell areas, and support T and B-cell proliferation. The homeostatic chemokines CXCL13 and CCL21 are expressed independently of TNFalpha and lymphotoxin at sites of iBALT formation. In addition, mice with iBALT, but lacking peripheral lymphoid organs, clear influenza infection and survive higher doses of virus than do normal mice, indicating that immune responses generated in iBALT are not only protective, but potentially less pathologic, than systemic immune responses. Thus, iBALT functions as an inducible secondary lymphoid tissue for respiratory immune responses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Northern
  • Bromodeoxyuridine
  • Bronchi / immunology*
  • Chemokine CCL21
  • Chemokine CXCL13
  • Chemokines, CC / metabolism
  • Chemokines, CXC / metabolism
  • Chromium Radioisotopes
  • DNA, Complementary / genetics
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Immunity, Cellular / immunology*
  • Immunohistochemistry
  • Lymphocytes / immunology
  • Lymphoid Tissue / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Orthomyxoviridae / immunology
  • Orthomyxoviridae Infections / immunology*
  • Sequence Analysis, DNA


  • Ccl21c protein, mouse
  • Chemokine CCL21
  • Chemokine CXCL13
  • Chemokines, CC
  • Chemokines, CXC
  • Chromium Radioisotopes
  • Cxcl13 protein, mouse
  • DNA, Complementary
  • Bromodeoxyuridine