Host immune response against Scedosporium species
Related Experiment Video
Updated: Jun 26, 2026
Whole Blood Assay with Dual Co-Stimulation for Antigen-Specific Analysis of Host Immunity to Fungal and Viral Pathogens
Published on: September 20, 2024
Emmanuel Roilides1, Maria Simitsopoulou, Aspasia Katragkou
13rd Department of Pediatrics, Aristotle University School of Medicine, Hippokration Hospital, Konstantinoupoleos 49, Thessaloniki, Greece. roilides@med.auth.gr
Abstract:
Scedosporium apiospermum and Scedosporium prolificans cause therapy-refractory infections in immunocompromised and immunocompetent hosts. While innate immune response is believed to be critical for the host defense against these fungi, its role has only recently been elucidated. Undefined pathogen-associated molecular patterns on the surface of conidia and hyphae are recognized by pattern-recognition receptors (PRRs) on the membrane of phagocytes, and the signal is transmitted intracellularly. PRRs that are important in the recognition of both fungal species are human Toll-like receptors (or Toll receptors in Drosophila melanogaster) and dectin-1. These induce signals responsible for the activation of genes leading to an effective host defense, especially those encoding pro-inflammatory cytokines. Both species are efficiently phagocytosed and elicit an oxidative burst by neutrophils and monocytes. While cytokines, such as interleukin-15, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor and interferon-gamma, have been found in vitro to variably modulate antifungal activity of human phagocytes, cytokines in vivo activities are less well documented. Certain antifungal agents exert immunopharmacological effects on phagocytes against S. apiospermum and S. prolificans. Translation of these in vitro findings to appropriate in vivo systems and into clinical trials may lead to improved strategies for augmenting innate host defenses in patients infected with these emerging pathogens.
Insights
Scedosporium fungi infections are challenging. Understanding innate immune responses, including pattern-recognition receptors (PRRs) and cytokines, is key to developing new therapies for these difficult-to-treat infections.
Area of Science:
- Mycology
- Immunology
- Infectious Diseases
Background:
- Scedosporium apiospermum and Scedosporium prolificans cause difficult-to-treat infections in various hosts.
- The innate immune system's role in combating these fungi is crucial but not fully understood.
- Pathogen-associated molecular patterns (PAMPs) on fungi are recognized by host pattern-recognition receptors (PRRs).
Purpose of the Study:
- To elucidate the role of innate immune responses in host defense against Scedosporium apiospermum and Scedosporium prolificans.
- To identify key pattern-recognition receptors (PRRs) involved in fungal recognition.
- To explore the impact of cytokines and immunopharmacological agents on phagocyte activity against these fungi.
Main Methods:
- Investigated the recognition of Scedosporium species by human Toll-like receptors (TLRs) and dectin-1.
- Assessed phagocytosis and oxidative burst activity of neutrophils and monocytes against Scedosporium conidia and hyphae.
- Examined the in vitro effects of various cytokines (e.g., IL-15, GM-CSF, G-CSF, IFN-γ) on phagocyte antifungal activity.
Main Results:
- Human Toll-like receptors (TLRs) and dectin-1 are critical PRRs for recognizing both Scedosporium species.
- Phagocytes efficiently engulf Scedosporium and mount an oxidative burst.
- Certain cytokines modulate phagocyte antifungal activity in vitro, and some antifungal agents show immunopharmacological effects.
Conclusions:
- Innate immune recognition via PRRs like TLRs and dectin-1 is vital for controlling Scedosporium infections.
- Cytokines and immunopharmacological agents show potential for enhancing host defense against these fungi.
- Further in vivo studies and clinical trials are needed to translate these findings into improved therapeutic strategies.
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