Production of IL-6 and TNF-α by the Macrophage-Like Cell Line RAW 264.7 After Treatment with a Cell Wall Extract of Candida albicans

Abstract

Treatment of the cell wall of Candida albicans with ethylenediamine yields an extract that is antigenic for both the humoral and cell-mediated arms of the immune system. This extract has been shown in previous studies by this laboratory and others to possess potent immunomodulatory activity. We report results here that show that treatment of the macrophage-like cell line RAW 264.7 with the ethylenediamine cell wall (EDA-CW) extract results in an increase in the production of both interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Our results also show that the EDA-CW extract possess potent costimulatory activity when combined with interferon-γ (IFN-γ). We have found, on the other hand, that EDA-CW extract-treated cells fail to produce elevated levels of IL-1 either alone or in combination with IFN-γ as a costimulus. Our analysis also shows that the activation of TNF-α production by the EDA-CW extract appears to be at the level of transcription, since Northern blot analysis shows that the increase in the level of TNF-α mRNA is essentially identical to the rise in TNF-α activity released. We suggest that a component of the immunomodulatory activity of the EDA-CW extract is via the activation of macrophage function.