Biology subjects

Lortal, L.

Publications and source records attributed to Lortal, L..

3 recordsLinked to original sources

bioRxiv2026

Therapeutic vulnerabilities of the drug-resistant fungal meningitis pathogen Cryptococcus neoformans

Treatment options are limited for the priority fungal pathogen Cryptococcus neoformans. We describe CRISPR-insert, a scalable gene inactivation method for global interrogation of drug targets. Genome-wide screens using this methodology combined with machine learning predict 1,297 essential genes under liberal criteria. Unexpectedly absent from this list is FKS1, encoding the target of echinocandin drugs to which C. neoformans is resistant. Contrary to longstanding literature, targeted deletion shows that FKS1 is not essential. Solid-state NMR reveals that fks1{triangleup} mutants lack {beta}-1,3-glucan, arguing against compensation by another synthase. We experimentally test essentiality predictions for genes lacking human orthologs, identifying high-priority drug target candidates. To uncover targets for combination therapies, we establish genome-scale quantitative genetic interaction mapping. We use this method to uncover synthetic lethal dependencies of echinocandin resistance determinants, including the druggable calcineurin and Cdc50-Apt1 pathways. CRISPR-insert illuminates therapeutic vulnerabilities of an invasive fungal pathogen.

microbiology↗

bioRxiv2026

The IL-1 Family Controls Acute Mucosal Fungal Infection and Mucosal-Systemic Dissemination.

Candida albicans is a major opportunistic pathogen in humans that is capable of breaching mucosal barriers and causing severe systemic infections with high mortality. How the host controls mucosal infection and prevents dissemination remains unclear but is essential for improving disease outcomes. Here, we demonstrate that C. albicans induces specific IL-1 family members, which are critical for initiating mucosal protection by controlling antimicrobial peptides, IL-17, and neutrophil responses. Loss of combined IL-1 family signalling led to severe mucosal C. albicans infection, which was eventually resolved by a potent neutrophil response. However, in neutropenic conditions (a key risk patient factor) abolishing IL-1 family signalling resulted in C. albicans dissemination, predominantly to the liver, mirroring clinical disease and leading to mortality. This study highlights the IL-1 family as a key initiator of mucosal immunity, restricting mucosal invasion and cooperating with neutrophils to prevent life- threatening systemic infections.

microbiology↗

bioRxiv2022

EGFR-MAPK adaptor proteins mediate the epithelial response to Candida albicans via the cytolytic peptide toxin, candidalysin

Candida albicans (C. albicans) is a dimorphic human fungal pathogen that can cause severe oropharyngeal candidiasis (OPC, oral thrush) in susceptible hosts. During invasive infection, C. albicans hyphae invade oral epithelial cells (OECs) and secrete candidalysin, a pore-forming cytolytic peptide that is required for fungal pathogenesis at mucosal surfaces. Candidalysin induces cell damage and activates multiple MAPK-based innate signaling events that collectively drive the production of downstream inflammatory mediators. The activities of candidalysin are also dependent on the epidermal growth factor receptor (EGFR), but how these signals are integrated is undefined. Here, we identified five essential adaptor proteins as key mediators of the epithelial response to C. albicans infection on cultured OECs, including growth factor receptor bound protein 2 (Grb2), Grb2-associated-binding protein 1 (Gab1), Src homology and collagen (Shc), SH2 containing protein tyrosine phosphatase-2 (Shp2) and casitas B-lineage lymphoma (c-Cbl). All these signaling effectors were inducibly phosphorylated in response to C. albicans, in a candidalysin-dependent mechanism but additionally required EGFR phosphorylation, matrix metalloproteinases (MMPs) and cellular calcium flux. Of these, Gab1, Grb2 and Shp2 were the dominant drivers of ERK1/2 signaling and production of downstream cytokines. Together, these results identify the key adaptor proteins that drive EGFR signaling mechanisms, which determine oral epithelial responses to C. albicans.

microbiology↗