S8.3b How fungal cell wall glycans modulate the activation of platelets ?

S8.3 HOW THE FUNGAL CELL WALL GLYCAN CAN MODULATE THE IMMUNE RESPONSE?, SEPTEMBER 23, 2022, 3:00 PM - 4:30 PM: : Platelets are the first circulating blood cells that interact and adhere to vascular lesions. They play an important role in vascular repair and maintenance of blood homeostasis. Platelets are involved in the immune defense of the host against many infections caused by bacteria, viruses, and fungi. Following infection, these microorganisms can alter platelet function leading to platelet activation. During fungal infection, β-glucans, mannan, and chitin, are critical components of Candida albicans, an opportunistic pathogenic yeast of humans. These fungal glycans play an important role in the modulation of the host response. They are released into the bloodstream and can be detected up to 10 days before the onset of clinical signs of invasive candidiasis. However, their role in the modulation of platelet activities is unknown. In our studies, we observed that β -glucans and chitin decrease platelet activation and modulate the production of inflammatory mediators, mediated by TLR4 or TLR8 respectively. These glycans also reduce platelet adherence to C. albicans and to polynuclear neutrophils, suggesting a process by which C. albicans can escape from cells of innate immunity by releasing cell wall polysaccharides into the close environment or the blood circulation. This study provides evidence that fungal glycans play a role in the modulation of the immune response and how C. albicans can escape from the innate immune response.