Sub-proteomic study on macrophage response to Candida albicans unravels new proteins involved in the host defense against the fungus

• Published in: Journal of proteomics 2012-08, Vol.75 (15), p.4734-4746
• Main Authors: Reales-Calderón, Jose Antonio, Martínez-Solano, Laura, Martínez-Gomariz, Montserrat, Nombela, César, Molero, Gloria, Gil, Concha
• Format: Article
• Language: English
• Subjects: apoptosis; Candida albicans; cytoskeleton; cytosol; fractionation; fungi; Galectin-3; gene expression regulation; immune response; Inflammation; Macrophages; mice; Oxidative stress; phagocytosis; proteins; proteomics; stress response; Subcellular; unfolded protein response
• ISSN: 1874-3919
• DOI: 10.1016/j.jprot.2012.01.037

In previous proteomic studies on the response of murine macrophages against Candida albicans, many differentially expressed proteins involved in processes like inflammation, cytoskeletal rearrangement, stress response and metabolism were identified. In order to look for proteins important for the macrophage response, but in a lower concentration in the cell, 3 sub-cellular extracts were analyzed: cytosol, organelle/membrane and nucleus enriched fractions from RAW 264.7 macrophages exposed or not to C. albicans SC5314 for 3h. The samples were studied using DIGE technology, and 17 new differentially expressed proteins were identified. This sub-cellular fractionation permitted the identification of 2 mitochondrion proteins, a membrane receptor, Galectin-3, and some ER related proteins, that are not easily detected in total cell extracts. Besides, the study of different fractions allowed us to detect, not only total increase in Galectin-3 protein amount, but its distinct allocation along the interaction. The identified proteins are involved in the pro-inflammatory and oxidative responses, immune response, unfolded protein response and apoptosis. Some of these processes increase the host response and others could be the effect of C. albicans resistance to phagocytosis. Thus, the sub-proteomic approach has been a very useful tool to identify new proteins involved in macrophage–fungus interaction. This article is part of a Special Issue entitled: Translational Proteomics. [Display omitted] ► 3 Subcellular macrophage extracts were analyzed by 2D-DIGE and 26 proteins identified. ► 17 new proteins involved in the macrophage response to C. albicans were identified. ► There was a pro-inflammatory response and an increase in the oxidative stress. ► There was a reduction in the proteins involved in ER stress response. ► Galectin-3 increases in amount, secretion and its membrane allocation along the interaction.