Project description:Candida albicans is a commensal of the urogenital tract and the predominant cause of vulvovaginal candidiasis (VVC). Roughly, 70% of otherwise healthy women succumb to VVC at least once in their life time. Elevated oestrogen levels are associated with C. albicans colonisation of the vagina and symptomatic infection. However, little is known about how C. albicans adapts to oestrogen. Here, we investigate how adaptation of C. albicans to elevated concentrations of oestrogen on the C. albicans host-pathogen interaction. Growth of C. albicans in physiological relevant concentrations of oestrogen promoted fungal innate immune evasion through reduction of both macrophage and neutrophil phagocytosis. Oestrogen-induced innate immune evasion was mediated via inhibition of opsonophagocytosis through enhanced Gpd2 dependent acquisition of Factor H on the fungal cell surface. The zebrafish larval model of infection confirmed that in vivo oestrogen and Gpd2 promote pathogenicity. Understanding the impact of oestrogen on C. albicans host-pathogen interaction will help improve our knowledge on how oestrogen promotes VVC.
Project description:To characterize the interaction of Candida albicans with intestinal epithelial cells (C2BBe1) from early fungal adhesion to invasion (up to 6 h) and the late translocation and damage phase (12 -24 h), we conducted dual RNA-sequencing of C. albicans-infected C2BBe1 cells over a 24 h time course, with sampling at 0 h, 45 min, 3 h, 6 h, 12 h, and 24 h.
Project description:The opportunistic fungal pathogen Candida albicans is a common cause of life-threatening nosocomial bloodstream infections. In the murine model of systemic candidiasis the kidney is the primary target organ while the fungal load declines over time in liver and spleen. To get a better understanding of the organ-specific differences in host-pathogen interaction during systemic murine candidiasis, we performed a time-course gene expression profiling to investigate the differential responses of murine kidney, liver and spleen and determined the fungal transcriptome in liver and kidney. We clearly demonstrate a delayed immune response on the transcriptional level in kidney accompanied by late induction of fungal stress response genes in this organ. In contrast, early upregulation of the proinflammatory response in the liver was associated with a fungal transcriptional profile resembling that of phagocytosed cells, suggesting that the resident phagocytic system contributes significantly to fungal control in the liver. Although no visible filamentation occurred in the liver, C. albicans hypha-associated genes were upregulated, indicating an uncoupling of gene expression and morphology during infection of this organ. In vitro the induction of hypha-associated gene expression in yeast cells led to altered interaction with macrophages, suggesting that the observed transcriptional changes affect host-pathogen interaction in vivo. Consistently, the combination of host and pathogen transcriptional data in an inference network model implied that C. albicans cell wall remodeling and metabolism were connected to the immune responses in kidney and liver. Furthermore, the network suggested links between fungal iron acquisition and amino acid metabolism in the kidney and host organ homeostasis. Thus, this work provides novel insights into the organ-specific host-pathogen interactions during systemic C. albicans infection.
Project description:Purpose: The purpose of this study was to simulataneously examine the host and fungal pathogen transcriptional profiles of four distinct infection fates during macrophage and Candida albicans interactions Methods: Membrane stained (Deep Red),primary, bone marrow derived, murine macrophages and Candida albicans expressing GFP and mCherry were exposed to each other over a four hour time course. Samples were collected at 0, 1, 2 and 4 hours and sorted for four infection subpopulations: 1. Macrophages which phagocytosed live C. albicans (GFP+ /mCherry+ /Deep Red +), 2. Macrophages which phagocytosed dead C. albicans (GFP- /mCherry+ /Deep Red +), 3. Uninfected macrophages(GFP- /mCherry- /Deep Red +) and 4. Unengulfed C. albicans (GFP+ /mCherry + /Deep Red -). Unexposed controls were also collected for some time points (i.e. macrophages never exposed to C. albicans and C. albicans never exposed to macrophages). Single macrophages infected with live or dead C. albicans were also sorted. Smart-seq2 was used to create libraries for both infection subpopulation and single, infected cell samples that were sequenced on Illumina’s Miseqand Nextseq. Basic quality assessment of Illumina reads and sample demultiplexing was done with Picard version 1.107 and Trimmomatic. Samples profiling exclusively the mouse transcriptional response were aligned to the mouse transcriptome generated from the v. Dec. 2011 GRCm38/mm10 and a collection of mouse rRNA sequences from the UCSC genome website. Samples profiling exclusively the yeast transcriptional response were aligned to the C. albicans transcriptome strain SC5314 version A21-s02-m09-r10 downloaded from Candida Genome Database. Samples containing both macrophages and C. albicans were aligned to a “composite transcriptome” made by combining the mouse transcriptome and C. albicans transcriptomes described above and alignment was done via BWA (version 0.7.10-r789.) Multi-reads (reads that aligned to both host and pathogen transcripts) were discarded. Then, each host or pathogen sample file were aligned to its corresponding reference using Bowtie2 and RSEM (v.1.2.21). Transcript abundance was estimated using transcripts per million (TPM). For subpopulation samples, TPM was calculated using edgeR, all as implemented in the Trinity package version 2.1.. Genes were considered differentially expressed only if they had a 4-fold change difference (> 4 FC) in TPM values and a false discovery rate below or equal to 0.001 (FDR < 0.001), unless specified otherwise. For single macrophages infected with C. albicans, samples were aligned to the combined transcriptome as described above and RSEM was used to calculate TPM. Results: We were able to simultaneously measure the host and fungal pathogen transcriptional profiles of four distinct infection fates during macrophage and Candida albicans interactions Conclusions: Our study represents an analysis of both distinct infection populations of macrophages and fungus.
Project description:Candida albicans is exposed to a different host environment during different site of infection. Thus, different virulence factors may be active during differenttypes of infection. However,little is known about the C. albicans genes that are required for the initiation and maintenance of candidiasis. To identify potential virulence factors relevant to hematogenously disseminated candidiasis, we determined the transcriptional response of C. albicans to human umbilical vein endothelial cells (HUVECs) in vitro. Keywords: cell interaction
Project description:Human serum amyloid A (SAA) is a major acute phase protein and shows a massive increase of concentration in plasma during inflammation. In the current study, we report that recombinant human and mouse SAA1 (rhSAA1 and rmSAA1) have a potent antifungal activity against the major fungal pathogen Candida albicans. rhSAA1 binds to the cell surface of C. albicans and promotes cell aggregation. At high concentrations, rhSAA1 disrupts the membrane integrity and induces rapid cell death of C. albicans. Further investigation demonstrates that rhSAA1 targets on the cell wall adhesin Als3 of C. albicans. Inactivation of ALS3 in C. albicans leads to remarkably decreased cell aggregation and death upon rhSAA1 treatment, implying that Als3 plays a critical role in SAA1 sensing. Moreover, deletion of the ALS3 transcriptional regulators such as AHR1, BCR1, and EFG1 in C. albicans results in a similar effect on cell responses to that of the als3/als3 mutant upon rhSAA1 treatment. Global gene expression profiling analysis indicates that rhSAA1 has a remarkable impact on the expression of cell wall- and metabolism-related genes in C. albicans. Our finding of the antifungal activity of rhSAA1 against C. albicans expands the function of this protein and would provide new insights into the understanding of the host-Candida interaction during infections.
Project description:The interaction between fungal pathogen and host innnate and adaptive immunity during infection is a complex and dynamic process. To resolve this, we chose the zebrafish model organism as the host to study C. albicans infection via systems biology approach. Transcriptome microarray data and histological analysis of surviving fish were sampled at different post-infection time points. Time-course microarray data following primary and secondary infection of zebrafish by Candida albicans were obatined. From this set of data, we constructed two intracellular protein–protein interaction (PPI) networks for primary and secondary responses of the host.