Effect of a combination therapy between IL-12 and soluble IL-4 receptor (sIL-4R) on Candida albicans and herpes simplex virus type 1 infections in thermally injured mice

The effectiveness of a combination using IL-12 and soluble IL-4 receptor (sIL-4R) to treat severe infections of herpes simplex virus type 1 (HSV-1) and Candida albicans in thermally injured mice was investigated. Although sIL-4R decreased burn-associated type 2 T-cell responses, the effect of sIL-4R was minimal on the morbidity and mortality of thermally injured mice exposed to 250 times LD₅₀ of HSV-1 or 10 times LD₅₀ of C. albicans. Compared with 100% mortality in control mice, mortality for HSV-1 and C. albicans was 40 and 20%, respectively, in thermally injured mice that received IL-12 and sIL-4R in combination. After stimulation with anti-CD3 monoclonal antibody, splenic T cells from thermally injured mice exposed to large amounts of HSV-1 or C. albicans did not produce gamma interferon (IFN-γ) into their culture fluids. However, IFN-γ was produced by splenic T cells from thermally injured and infected mice treated with IL-12 and sIL-4R in combination. These results suggest that therapeutic treatment with a combination of IL-12 and sIL-4R may be effective by inducing type 1 T-cell responses in thermally injured mice exposed to large amounts of HSV-1 or C. albicans.