Beschreibung:
<jats:title>Abstract</jats:title><jats:p>The involvement of CD14 in lipopolysaccharide (LPS) recognition and signaling has been demonstrated in several studies. For this reason, we investigated whether the resistance of <jats:italic>Lps</jats:italic><jats:sup><jats:italic>d</jats:italic></jats:sup> mice to LPS might be related to an impaired CD14 expression. We compared the <jats:italic>in vivo</jats:italic> and <jats:italic>in vitro</jats:italic> expression of CD14 in <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup> (LPS sensitive) and <jats:italic>Lps</jats:italic><jats:sup><jats:italic>d</jats:italic></jats:sup> mice, and its modulation by LPS, killed gramnegative and gram‐positive bacteria and double‐stranded (ds)RNA. Untreated <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup> and <jats:italic>Lps</jats:italic><jats:sup><jats:italic>d</jats:italic></jats:sup> cultured macrophages (MΦ), expressed similar amounts of CD14 mRNA and membrane‐bound (m)CD14. LPS enhanced CD14 expression only in <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup> MΦ, while all bacteria, or dsRNA, enhanced CD14 in <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup> and <jats:italic>Lps</jats:italic><jats:sup><jats:italic>d</jats:italic></jats:sup> MΦ. Similarly, <jats:italic>in vivo</jats:italic> administration of LPS induced or enhanced CD 14 mRNA in different organs of <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup> mice only, while bacteria or dsRNA in both types of mouse. Furthermore, exogenous recombinant tumor necrosis factor (TNF) induced <jats:italic>in vivo</jats:italic> and <jats:italic>in vitro</jats:italic> enhanced CD 14 expression in <jats:italic>Lps</jats:italic><jats:sup><jats:italic>n</jats:italic></jats:sup>, <jats:italic>Lps</jats:italic><jats:sup><jats:italic>d</jats:italic></jats:sup> and also in TNF receptor 2‐deficient (TNFR2−/−) mice, but failed to do so in TNFR1−/− mice, showing that TNFR1 mediates the effect of TNF on CD14. However, LPS, bacteria and dsRNA induced CD14 in both TNFR2−/− and TNFR1−/− mice to a similar extent, revealing that this induction does not require TNF signaling.</jats:p>