Biology subjects

Curry, J. M.

Publications and source records attributed to Curry, J. M..

3 recordsLinked to original sources

bioRxiv2025

Candida albicans activates Staphylococcus aureus virulence regulatory systems to drive toxin-mediated human cell death

Co-infection with Staphylococcus aureus and Candida albicans leads to worsened disease severity compared to mono-microbial infection. Because our understanding of the mechanisms driving enhanced disease severity during co-infection is limited, we sought to evaluate how interactions with C. albicans regulate S. aureus virulence towards host cells. We determined that C. albicans enhances S. aureus cytotoxicity towards murine monocytes via a mechanism requiring the Agr system. Agr is a major regulator of S. aureus virulence factors and was previously shown to be activated by C. albicans, but the Agr-regulated virulence factors driving immune cell death are unknown. We identified that enhanced murine monocyte cell death requires the -type phenol soluble modulins and {psi}-hemolysin. Because several S. aureus toxins have species-specific effects, we also tested how co-culture impacts cytotoxicity towards human monocytes. Unexpectedly, we discovered that C. albicans induces robust cytotoxicity of an S. aureus agr mutant ({Delta}agr), which is completely non-toxic towards murine monocytes. Using reporter strains and combinatorial mutants, we identified that co-culture activates the SaeRS regulatory system in S. aureus, and SaeRS is required for human-specific cytotoxicity. We further discovered that the SaeRS-regulated toxin Panton-Valentine Leukocidin (PVL) drives S. aureus {Delta}agr cytotoxicity following co-culture. Finally, we observed similar cytotoxicity phenotypes using both S. aureus and C. albicans clinical isolates, demonstrating broad conservation of this interaction. Interestingly, the magnitude by which C. albicans isolates induce cytotoxicity of S. aureus {Delta}agr varies among strains tested. Overall, this study identifies that C. albicans activates a major S. aureus virulence regulatory system in a typically non-toxic strain, triggering S. aureus to induce potent human-selective cell death.

microbiology↗

bioRxiv2024

Tumor microenvironment governs the prognostic landscape of immunotherapy for head and neck squamous cell carcinoma: A computational model-guided analysis

Immune checkpoint inhibition (ICI) has emerged as a critical treatment strategy for squamous cell carcinoma of the head and neck (HNSCC) that halts the immune escape of the tumor cells. Increasing evidence suggests that the onset, progression, and lack of/no response of HNSCC to ICI are emergent properties arising from the interactions within the tumor microenvironment (TME). Deciphering how the diversity of cellular and molecular interactions leads to distinct HNSCC TME subtypes subsequently governing the ICI response remains largely unexplored. We developed a cellular-molecular model of the HNSCC TME that incorporates multiple cell types, cellular states, and transitions, and molecularly mediated paracrine interactions. An exhaustive simulation of the HNSCC TME network shows that distinct mechanistic balances within the TME give rise to the five clinically observed TME subtypes such as immune/non-fibrotic, immune/fibrotic, fibrotic only and immune/fibrotic desert. We predict that the cancer-associated fibroblast, beyond a critical proliferation rate, drastically worsens the ICI response by hampering the accessibility of the CD8+ killer T cells to the tumor cells. Our analysis reveals that while an Interleukin-2 (IL-2) + ICI combination therapy may improve response in the immune desert scenario, Osteopontin (OPN) and Leukemia Inhibition Factor (LIF) knockout with ICI yields the best response in a fibro-dominated scenario. Further, we predict Interleukin-8 (IL-8), and lactate can serve as crucial biomarkers for ICI-resistant HNSCC phenotypes. Overall, we provide an integrated quantitative framework that explains a wide range of TME-mediated resistance mechanisms for HNSCC and predicts TME subtype-specific targets that can lead to an improved ICI outcome.

cancer biology↗

bioRxiv2021

Multimodal genomic markers predict immunotherapy response in the head and neck squamous cell carcinoma

Immune checkpoint blockade (ICB) therapy has had a major impact on the clinical management of head and neck squamous cell carcinoma (HNSCC). However, clinical responses to ICB are observed in only a fraction of patients. In the present paper, we used multimodal approaches to a) evaluate the utility of existing ICB biomarkers including tumor mutation burden (TMB), microsatellite instability (MSI), and a T-cell specific signature in predicting therapy response in HNSCC using TCGA cohort, and; b) identify a novel molecular signature to predict ICB therapy response using an ICB clinical trial of HNSCC. Our results confirm previous reports showing TMB efficacy as a biomarker and its outcome can be influenced by age, tumor sub-site, and smoking status; and that High-TMB and high-MSI tumors are associated with T-cell signature, and better survival probability in the HNSCC. We go on to demonstrate that High-TMB and high-MSI utilizes cell-cycle/cell proliferation processes for their molecular functionality; and identify a novel Cell Proliferation ICB-therapy Predicting (CPIP) signature capable of predicting ICB therapy response in HNSCC, retrospectively, where traditional biomarkers of ICB response were insufficient. In summary, the present study defines strategies and novel signatures that can be appropriately used for patient selection for ICB therapy that can improve the clinical outcomes of HNSCC patients.

genomics↗