Cell-specific interleukin-15 and interleukin-15 receptor subunit expression and regulation in pneumococcal pneumonia--comparison to chlamydial lung infection.
Interleukin (IL)-15 has critical impact on the homeostasis and activation of natural killer cells, natural killer T cells, gammadeltaT cells, and CD8(+)T cells, and contributes to antimicrobial defenses particularly at mucosal sites. The respiratory tract comprises a large mucosal surface and harbors significant amounts of lymphocytes, however the expression pattern of IL-15 in the lung and its role in local immune responses are largely unknown. We therefore analyzed the differential expression of IL-15 and the IL-15 receptor (IL-15R) complex in the lungs of mice and demonstrated substantial constitutive expression in bronchial and alveolar epithelial cells, alveolar macrophages, and vascular smooth muscle cells, implicating contribution to pulmonary immune cell homeostasis already under normal conditions. The induction of pneumococcal pneumonia but not the infection with Chlamydophila pneumoniae evoked a significant up-regulation of IL-15 on alveolar macrophages and bronchial epithelial cells, with the latter presenting de-novo expression of IL-15 on their basolateral surface and additional up-regulation of IL-15Ralpha. Moreover, transcriptome analysis as well as semi-quantitative PCR indicated at least partial transcriptional regulation in mice lungs. In conclusion IL-15 is suggested being of functional importance in the pulmonary immune response against pneumococcal pneumonia.
Hocke
Andreas C
AC
Charité - Universitätsmedizin Berlin, Department of Internal Medicine, Infectious and Respiratory Diseases, Chariteplatz 1, 10117 Berlin, Germany.
Lampe
Matthias P
MP
Witzenrath
Martin
M
Mollenkopf
Hans
H
Zerrahn
Jens
J
Schmeck
Bernd
B
Kessler
Ulrich
U
Krüll
Matthias
M
Hammerschmidt
Sven
S
Hippenstiel
Stefan
S
Schütte
Hartwig
H
Suttorp
Norbert
N
Rosseau
Simone
S
D000818:Animals; D002690:Chlamydia Infections / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D053631:Interleukin Receptor Common gamma Subunit / Q000096:biosynthesis / Q000235:genetics; D019409:Interleukin-15 / Q000096:biosynthesis / Q000235:genetics*; D053720:Interleukin-15 Receptor alpha Subunit / Q000096:biosynthesis / Q000235:genetics; D053646:Interleukin-2 Receptor beta Subunit / Q000096:biosynthesis / Q000235:genetics; D008168:Lung / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D011018:Pneumonia, Pneumococcal / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D053647:Receptors, Interleukin-15 / Q000096:biosynthesis / Q000235:genetics*
D053631:Interleukin Receptor Common gamma Subunit; D019409:Interleukin-15; D053720:Interleukin-15 Receptor alpha Subunit; D053646:Interleukin-2 Receptor beta Subunit; D053647:Receptors, Interleukin-15