Protection of neutropenic mice from lethal Candida albicans infection by recombinant interleukin 1

Abstract

Natural and synthetic immunomodulators that increase nonspecific resistance to infection are also known to induce interleukin 1 (IL1) production. Previous studies have demonstrated a protective effect of recombinant human IL1β against death from infection caused by Pseudomonas aeruginosa. In the present study we investigated the effect of IL 1β or IL 1α on the survival of neutropenic mice with a lethal Candida albicans infection. Mice with cyclophosphamide-induced neutropenia were injected with 3 × 10⁵ C. albicans i.v. When 80 ng IL 1β was given as a single i.p. injection 24 h before the infection, survival compared to that in control animals was as follows: 100% vs. 97% at 24 h, 83% vs. 70% at 48 h and 70% vs. 23% at 72 h after the infection (pCandida cultured from the blood, liver, spleen, and kidney were not significantly different in IL 1β-treated and control animals. Passive transfer of serum obtained from mice pretreated with IL 1 to recipient mice did not provide protection against a subsequent lethal candidal infection. In conclusion, the present study demonstrates that IL 1β and IL 1α prolong survival in neutropenic mice with a lethal C. albicans infection.