Biology subjects

Millet, N.

Publications and source records attributed to Millet, N..

4 recordsLinked to original sources

bioRxiv2024

Non-canonical IL-22 receptor signaling remodels the mucosal barrier during fungal immunosurveillance

Mucosal barrier integrity is vital for homeostasis with commensal organisms while preventing pathogen invasion. We unexpectedly found that fungal-induced immunosurveillance enhances resistance to fungal outgrowth and tissue invasion by remodeling the oral mucosal epithelial barrier in mouse models of adult and neonatal Candida albicans colonization. Epithelial subset expansion and tissue remodeling were dependent on interleukin-22 (IL-22) and signal transducer and activator of transcription 3 (STAT3) signaling, through a non-canonical receptor complex composed of glycoprotein 130 (gp130) coupled with IL-22RA1 and IL-10RB. Immunosurveillance-induced epithelial remodeling was restricted to the oral mucosa, whereas barrier architecture was reset once fungal-specific immunity developed. Collectively, these findings identify fungal-induced transient mucosal remodeling as a critical determinant of resistance to mucosal fungal infection during early stages of microbial colonization.

immunology↗

bioRxiv2024

Synergistic cross-kingdom host cell damage between Candida albicans and Enterococcus faecalis

The fungus Candida albicans and the Gram-positive bacterium Enterococcus faecalis share mucosal niches in the human body. As opportunistic pathogens, both are found to expand population size during dysbiosis, and can cause severe systemic infections in susceptible individuals. Here, we show that the presence of C. albicans results in increased host cell damage by E. faecalis. Furthermore, E. faecalis aggravates oropharyngeal candidiasis in mice. Increased damage is mediated by enterococcal cytolysin, and involves both physical interaction and altered glucose availability. Physical interaction promotes accumulation of bacteria on host cells, facilitating contact of cytolysin with host cells. Glucose depletion by the metabolic activity of the fungus sensitized host cells to cytolysin. This work illustrates how a complex interplay between fungi and bacteria can result in detrimental consequences for the host.

microbiology↗

bioRxiv2024

Sensory neurons regulate stimulus-dependent humoral immunity

Sensory neurons sense pathogenic infiltration, informing immune coordination of host defense. However, sensory neuron-immune interactions have been predominantly shown to drive innate immune responses. Humoral memory, whether protective or destructive, is acquired early in life - as demonstrated by both early exposure to streptococci and allergic disease onset. Our study further defines the role of sensory neuron influence on humoral immunity in the lung. Using a murine model of Streptococcus pneumonia pre-exposure and infection and a model of allergic asthma, we show that sensory neurons are required for B-cell and plasma cell recruitment and antibody production. In response to S. pneumoniae, sensory neuron depletion resulted in a larger bacterial burden, reduced B-cell populations, IgG release, and neutrophil stimulation. Conversely, sensory neuron depletion reduced B-cell populations, IgE, and asthmatic characteristics during allergen-induced airway inflammation. The sensory neuron neuropeptide released within each model differed. With bacterial infection, vasoactive intestinal polypeptide (VIP) was preferentially released, whereas substance P was released in response to asthma. Administration of VIP into sensory neuron-depleted mice suppressed bacterial burden and increased IgG levels, while VIP1R deficiency increased susceptibility to bacterial infection. Sensory neuron-depleted mice treated with substance P increased IgE and asthma, while substance P genetic ablation resulted in blunted IgE, similar to sensory neuron-depleted asthmatic mice. These data demonstrate that the immunogen differentially stimulates sensory neurons to release specific neuropeptides that specifically target B-cells. Targeting sensory neurons may provide an alternate treatment pathway for diseases involved with insufficient and/or aggravated humoral immunity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=146 SRC="FIGDIR/small/574231v3_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1a96e0org.highwire.dtl.DTLVardef@1a75c97org.highwire.dtl.DTLVardef@afd6f8org.highwire.dtl.DTLVardef@4a6666_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2021

IL-23 signaling prevents ferroptosis-driven renal immunopathology during candidiasis

During infection the host relies on pattern-recognition receptors to sense invading fungal pathogens to launch immune defense mechanisms. While fungal recognition and immune effector responses are organ and cell type specific, during disseminated candidiasis myeloid cells exacerbate collateral tissue damage. However, the complex interplay between protective antifungal immunity and immunopathology remains incompletely understood. The {beta}-glucan receptor ephrin type-A 2 receptor (EphA2) is required to initiate mucosal inflammatory responses during oral Candida infection. Here we report that Epha2 promotes renal immunopathology during disseminated candidiasis. EphA2 deficiency leads to reduced renal inflammation and injury. Comprehensive analyses reveal that EphA2 limits IL-23 secretion in dendritic cells, while IL-23 signaling prevents ferroptotic myeloid cell death during infection. Further, ferroptosis aggravates inflammation during infection, while at the same time reducing the fungal killing capacity of macrophages. Thus, we identify ferroptotic cell death as a critical pathway of Candida-mediated renal immunopathology that opens a new avenue to tackle Candida infection and inflammation.

immunology↗