Endotoxin-induced, neutrophil-mediated endothelial cytotoxicity is enhanced by T-lymphocytes.
The role of T-lymphocytes (T cells) and interferon-gamma (IFN-gamma) in the pathogenesis of sepsis-induced microvascular endothelial injury remains unclear. We sought to determine whether the syngeneic coculture of human T cells in the presence of LPS promoted subsequent neutrophil (PMN)-mediated endothelial cytotoxicity. Syngeneic T cells were cocultured with 51Cr-loaded human adipose microvascular endothelial cell (HAMVEC) monolayers in the absence and presence of LPS. Subsequent PMN-mediated HAMVEC cytotoxicity (measured as percent specific 51Cr release) was absent in cultures that contained T cells but no LPS and was significantly increased when T cells were cocultured in the presence of LPS. This was true both following addition of unstimulated PMNs (-0.8 +/- 3.0% vs 4.9 +/- 4.7% for T cells alone vs T cells plus LPS, respectively) and PMNs stimulated with f-Met-Leu-Phe (-0.4 +/- 3.1% vs 10.7 +/- 3.0% for T cells alone vs T cells plus LPS, respectively). Increased cytotoxicity was associated with increased expression of the endothelial adhesion molecules ICAM-1 and VCAM-1. Control experiments failed to demonstrate cytotoxicity when HAMVEC were cultured in the presence of IFN-gamma alone, LPS alone, or T cells without LPS. It appears that there is a necessary requirement of both LPS and (presumably activated) T cells or their products (other than IFN-gamma) for enhanced PMN-mediated endothelial cytotoxicity. This phenomenon may also be mediated by increased expression of endothelial adhesion molecules that promote subsequent PMN adhesion.
Tennenberg
S D
SD
Department of Surgery, Detroit Veterans Affairs Medical Center, Michigan, USA.
Weller
J J
JJ
D002470:Cell Survival / Q000187:drug effects; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D004731:Endotoxins / Q000494:pharmacology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000502:physiology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
D004731:Endotoxins; D011994:Recombinant Proteins; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma