Enhancement of host defence against infection with Listeria monocytogenes in newborn mice by various recombinant cytokines
Chen, Y.
Hokkaido Journal of Medical Science 66(1): 41-48
1991
ISSN/ISBN: 0367-6102 PMID: 1900802 Document Number: 381187
Neonatal mice within 24 h of birth were highly susceptible to infection of Listeria monocytogenes. The 50% lethal dose of bacterial cells for neonates and adult mice was 6.3 .times. 101 CFU and 3.2 .times. 106 CFU, respectively. A single intraperitoneal injection of recombinant murine interferon-.gamma. (rMuIFN-.gamma.) protected neonates from the simultaneous challenge with a lethal dose of L. monocytogenes. The protection of rMuIFN-.gamma. was consistently observed in neonates at doses more than 4 .times. 102 IU (0.1 .mu.g protein) per mouse. The bacterial growth in the spleens and livers of neonates treated with rMuIFN-.gamma. was significantly suppressed in comparison with that in the untreated neonates. Furthermore, survived neonates from the infection with L. monocytogenes showed an acquired resistance the intravenous injection of lethal dose of L. monocytogenes 4 weeks after the primary infection, and this resistance significantly increased in mice that has been treated with rMuIFN-.gamma. In addition, to rMuIFN-.gamma., recombinant human interleukin-1.beta. and recombinant human tumor necrosis factor -.alpha. were also effective on rescue from the lethal infection with Listeria monocytogenes in neonatal mice, but the effect was seen only in the limited doses. On the other hand, recombinant murine IFN-.beta. and recombinant human IL-2 were not effective at all. These results suggest that rMuIFN-.gamma. rather than other cytokines might endow neonatal mice with the enhanced antilisterial resistance involving macrophages and T lymphocytes.