Quantitative proteomic analysis of epithelial cells of the female genital tract identifies type i interferons pathway as relevant in the host response against Candida albicans

RODRIGUEZ E, ANGIOLINI SC, HERNANDEZ ML, ICELY PA, STEMPIN C, VARGAS L, GIL GARCÍA C AND CE SOTOMAYOR CE.

Córdoba

Congreso; XIX Forum on Fungal Infection in the Clinical Practice, INFOCUS 2021; 2021

INFOCUS

Vulvovaginal candidiasis (VVC) is an acute inflammatory disease caused primarily by Candida albicans (Ca). VVC affects more than 75% of healthy women at least once in their lifetime. Despite the extensive knowledge about host predisposing factors, many of the mechanisms that govern the complex Ca-Epithelial Cell (EC) interaction and the immune mediators involved in the response to the fungus have not been completely clarified. Type I interferons (IFNs-I) have been traditionally associated with antiviral immune responses, however, their importance in host defense against fungal pathogens is being increasingly appreciated. At present, it is not well known the role of IFNs-I in Ca infections at mucosal level, especially in the cervicovaginal tract. Objective: We aimed to study the biological processes and cellular pathways differentially regulated in EC of the female genital tract after interaction with Ca through a label-free quantitative proteomic study. Methods: We performed an in vitro model of VVC using the human cervical EC line, HeLa. A quantitative proteomic approach using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) was performed to study the changes in the abundance of EC proteins after interaction with Ca SC5314 during 4h (5:1 Ca:cell ratio). Unstimulated EC were considered as control. Four biological replicates of each condition were analyzed. In terms of biological significance, we only took into consideration proteins that were quantified in at least three biological replicates with at least two peptides and a p-value< 0.05. The bioinformatic analysis of differentially abundant proteins were carried out using Gene Ontology and REVIGO for GO terms enrichment analysis and Reactome for pathways analysis. Results: A total of 216 differentially abundant proteins upon Ca interaction were observed in EC (95 up-regulated and 121 down-regulated). GO term enrichment analysis showed that the more abundant proteins were mainly involved in nucleocytoplasmic transport, regulation of metabolism and immune response, whereas the less abundant proteins were associated with mRNA metabolism and cornification, among others. Pathway enrichment analysis of proteins specifically up-regulated after Ca stimulation confirmed ?Antiviral mechanism by IFN-stimulated genes? (p-value=9.98e-7) as the most relevant pathway in response to Ca. Furthermore, other relevant pathways were closely related to IFNs-I signalling mechanisms such as ?NS1 mediated effects on host pathways? (p-value=2.94e-6), ?ISG15 antiviral mechanisms? (p-value=5.81 e-6) and ?Interferon signaling? (p-value=3.57e-3). On the other hand, down-regulated proteins were involved in ?Peptide chain elongation? (p-value=2.07e-11), ?Selenocysteine synthesis? (p-value=3.51e-11) and ?Viral mRNA traslation? (p-valor8.40e-11). Conclusion: Taken together, quantitative proteomics offered new insights into the biological processes regulated in EC of the female genital tract after interaction with Ca and also provided strong evidence about the relevance of IFNs-I pathway activation in response to the fungus. These findings contribute to a better understanding of the host-pathogen interaction and can direct new studies on mechanisms that may lead to novel host-directed treatment strategies.