1. Saps1–3 Antigens in Candida albicans: Differential Modulation Following Exposure to Soluble Proteins, Mammalian Cells, and Infection in Mice
- Author
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Pedro F. Barbosa, Diego S. Gonçalves, Lívia S. Ramos, Thaís P. Mello, Lys A. Braga-Silva, Marcia R. Pinto, Carlos P. Taborda, Marta H. Branquinha, and André L. S. Santos
- Subjects
Candida albicans ,secreted aspartic proteases ,Saps’ induction ,organic source of nitrogen ,cellular interaction ,infection ,Other systems of medicine ,RZ201-999 - Abstract
The secreted aspartic peptidases (Saps) of Candida albicans play crucial roles in various steps of fungal–host interactions. Using a flow cytometry approach, this study investigated the expression of Saps1–3 antigens after (i) incubation with soluble proteins, (ii) interaction with mammalian cells, and (iii) infection in immunosuppressed BALB/c mice. Supplementation strategies involving increasing concentrations of bovine serum albumin (BSA) added to yeast carbon base (YCB) medium as the sole nitrogenous source revealed a positive and significant correlation between BSA concentration and both the growth rate and the percentage of fluorescent cells (%FC) labeled with anti-Saps1–3 antibodies. Supplementing the YCB medium with various soluble proteins significantly modulated the expression of Saps1–3 antigens in C. albicans. Specifically, immunoglobulin G, gelatin, and total bovine/human sera significantly reduced the %FC, while laminin, human serum albumin, fibrinogen, hemoglobin, and mucin considerably increased the %FC compared to BSA. Furthermore, co-cultivating C. albicans yeasts with either live epithelial or macrophage cells induced the expression of Saps1–3 antigens in 78% (mean fluorescence intensity [MFI] = 152.1) and 82.7% (MFI = 178.2) of the yeast cells, respectively, compared to BSA, which resulted in 29.3% fluorescent cells (MFI = 50.9). Lastly, the yeasts recovered from the kidneys of infected immunosuppressed mice demonstrated a 4.8-fold increase in the production of Saps1–3 antigens (MFI = 246.6) compared to BSA, with 95.5% of yeasts labeled with anti-Saps1–3 antibodies. Altogether, these results demonstrated the positive modulation of Saps’ expression in C. albicans by various key host proteinaceous components, as well as by in vitro and in vivo host challenges.
- Published
- 2024
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