Dual effect of IL-4 on resistance to systemic gram-negative infection and production of TNF-alpha

To determine the effect of interleukin 4 (IL-4) administration in a live se psis model characterised by high-level production of tumour necrosis factor alpha (TNF-alpha), mice infected systemically with lethal or sublethal ino cula of Pseudomonas aeruginosa were given the recombinant cytokine at diffe rent times before infection. Improved survival and decreased TNF-alpha prod uction mere observed in lethally infected mice treated with the cytokine 1 day before challenge. In contrast, increased mortality and overproduction o f TNF-alpha were observed in sublethally infected mice given IL-4 at the ti me of infection, (C) 2000 Academic Press.