Diffusible signal to murine alveolar macrophages from lipopolysaccharide- and Escherichia coli-stimulated lung Type II epithelial cells.
OBJECTIVE
To demonstrate a diffusible intercellular macrophage activation factor secreted by Type II alveolar epithelial cells (AECs) in transwell co-cultures.


METHODS
T(7), our Type II conditionally immortalized AEC line; MH-S, an alveolar macrophage cell line; Lipopolysaccharide (LPS) or uv-killed Escherichia coli (UVEC) for antigen presentation.


METHODS
LPS or UVEC stimulation of T(7) cells in the lower chamber was investigated for ability to activate MH-S cells in the upper chamber, as assayed by nitric oxide production and western blots for inducible nitric oxide synthase-2.


RESULTS
Both transwell and UVEC-conditioned medium experiments showed secretion of an MH-S activation factor by T(7) cells. Many common inflammatory cytokines were ruled out as this immunoactivator.


CONCLUSIONS
Demonstration of a diffusible activation factor produced by Type II AECs supports their potential role as first responders of innate immunity in the lung.
Farberman
M M
MM
Department of Pathology, Saint Louis University Health Sciences Center, 3635 Vista Avenue, St. Louis, MO 63110, USA.
Hoffmann
J W
JW
Ryerse
J S
JS
Demello
D E
DE
D000818:Animals; D002460:Cell Line; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000737:chemistry; D004058:Diffusion; D004847:Epithelial Cells / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008168:Lung / Q000166:cytology / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000276:immunology*; D051379:Mice; D015398:Signal Transduction
D017077:Culture Media, Conditioned; D008070:Lipopolysaccharides