Influence of Tumour Condition on the Macrophage Activity in Candida albicans Infection

• Published in: Scandinavian journal of immunology 2009-07, Vol.70 (1), p.10-17
• Main Authors: Venturini, J, de Camargo, M.R, Félix, M.C, Vilani-Moreno, F.R, de Arruda, M.S.P
• Format: Article
• Language: English
• Subjects: Animals; Candida albicans; Candidiasis - complications; Candidiasis - immunology; Carcinoma, Ehrlich Tumor - complications; Carcinoma, Ehrlich Tumor - immunology; Hydrogen Peroxide - metabolism; Macrophages, Peritoneal - immunology; Macrophages, Peritoneal - metabolism; Male; Mice; Nitric Oxide - biosynthesis; Opportunistic Infections - complications; Opportunistic Infections - immunology; Tumor Necrosis Factor-alpha - biosynthesis
• ISSN: 0300-9475; 1365-3083
• DOI: 10.1111/j.1365-3083.2009.02260.x

To better understand the interactions between opportunistic fungi and their hosts, we investigated hydrogen peroxide (H₂O₂), nitric oxide and TNF-α production by peritoneal macrophages from Ehrlich tumour-bearing mice (TBM) during microbial infections. For this purpose, TBM at days 7, 14 and 21 of tumour progression were inoculated intraperitoneally with C. albicans and evaluated after 24 and 72 h. We observed that TBM showed significant increases in H₂O₂, TNF-α levels and fungal clearance at day 7 after C. albicans infection. However, as the tumour advanced, there was a progressive decline in the release of H₂O₂ and TNF-α that was paired with the dissemination of C. albicans. These results demonstrate that protective macrophage activities against Candida albicans are limited to the initial stages of tumour growth; continued solid tumour growth weakened the macrophage response and as a consequence, weakened the host's susceptibility to opportunistic infections.