Targeted mutation of TNF receptor I rescues the RelA-deficient mouse and reveals a critical role for NF-kappa B in leukocyte recruitment - PubMed (original) (raw)

Targeted mutation of TNF receptor I rescues the RelA-deficient mouse and reveals a critical role for NF-kappa B in leukocyte recruitment

E Alcamo et al. J Immunol. 2001.

Abstract

NF-kappaB binding sites are present in the promoter regions of many acute phase and inflammatory response genes, suggesting that NF-kappaB plays an important role in the initiation of innate immune responses. However, targeted mutations of the various NF-kappaB family members have yet to identify members responsible for this critical role. RelA-deficient mice die on embryonic day 15 from TNF-alpha-induced liver degeneration. To investigate the importance of RelA in innate immunity, we genetically suppressed this embryonic lethality by breeding the RelA deficiency onto a TNFR type 1 (TNFR1)-deficient background. TNFR1/RelA-deficient mice were born healthy, but were susceptible to bacterial infections and bacteremia and died within a few weeks after birth. Hemopoiesis was intact in TNFR1/RelA-deficient newborns, but neutrophil emigration to alveoli during LPS-induced pneumonia was severely reduced relative to that in wild-type or TNFR1-deficient mice. In contrast, radiation chimeras reconstituted with RelA or TNFR1/RelA-deficient hemopoietic cells were healthy and demonstrated no defect in neutrophil emigration during LPS-induced pneumonia. Analysis of RNA harvested from the lungs of mice 4 h after LPS insufflation revealed that the induction of several genes important for neutrophil recruitment to the lung was significantly reduced in TNFR1/RelA-deficient mice relative to that in wild-type or TNFR1-deficient mice. These results suggest that TNFR1-independent activation of RelA is essential in cells of nonhemopoietic origin during the initiation of an innate immune response.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances

LinkOut - more resources