Pneumocystis carinii Cell Wall β-Glucans Initiate Macrophage Inflammatory Responses through NF-κB Activation

Purified Pneumocystis carinii cell-wall beta-glucan was used to stimulate macrophages. It activated NF-kappa-B with slower and longer-lasting kinetics than bacterial LPS, and an NF-kappa-B antagonist reduced the response. TLR4 was not required, while MyD88 deficiency partially reduced signaling, indicating a distinct receptor pathway. This inflammatory cell study concerns a pathogenic fungal wall component, not an Aureobasidium supplement or a therapeutic outcome in humans.