Medhasi Sadeep, Sriwarom Apichaya, Permpalung Nitipong, Torvorapanit Pattama, Plongla Rongpong, Chindamporn Ariya, Worasilchai Navaporn
Department of Transfusion Medicine and Clinical Microbiology, Faculty of Allied Health Sciences, Chulalongkorn University, 154 Soi Chula12, Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Research Unit of Medical Mycology Diagnosis, Chulalongkorn University, Bangkok, Thailand.
Sci Rep. 2025 Feb 12;15(1):5210. doi: 10.1038/s41598-025-88962-w.
Pythium insidiosum-antigen (PIA) immunotherapy has been used to treat human pythiosis. This study compared PIA-stimulated and unstimulated neutrophils on zoospore viability of P. insidiosum strains. We cultured and collected zoospores of 6 P. insidiosum strains, CBS 777.84, ATCC 58643, ATCC 90586, PEC1, PC10, and CBS 101039. PIA concentrations of 0.01, 0.1, 1, and 10 µg/ml were prepared and were used to stimulate neutrophils isolated from healthy volunteers. The MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay was used to calculate the zoospore viability of P. insidiosum strains. Neutrophils stimulated with 0.01 or 0.1 µg/ml PIA, or both, showed a significant reduction in the viability of zoospores of CBS 777.84, ATCC 58643, CBS 101039, PC10, and PEC1 strains. Furthermore, 1 µg/ml PIA-induced neutrophils elicited a significant decrease in the viability of zoospores of ATCC 58643, CBS 101039, and PC10 strains. However, a higher dose of PIA (10 µg/ml) did not demonstrate superiority in reducing the zoospore viability of all six strains. Our findings suggest that PIA immunotherapy improves the zoospore-killing activity of neutrophils, and neutrophils might be involved in the forefront mechanism responsible for the beneficial effects of PIA immunotherapy.
腐皮镰刀菌抗原（PIA）免疫疗法已被用于治疗人类腐皮病。本研究比较了PIA刺激和未刺激的中性粒细胞对腐皮镰刀菌菌株游动孢子活力的影响。我们培养并收集了6株腐皮镰刀菌菌株（CBS 777.84、ATCC 58643、ATCC 90586、PEC1、PC10和CBS 101039）的游动孢子。制备了浓度为0.01、0.1、1和10μg/ml的PIA，并用于刺激从健康志愿者中分离出的中性粒细胞。采用MTT（3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐）法计算腐皮镰刀菌菌株的游动孢子活力。用0.01或0.1μg/ml PIA或两者刺激的中性粒细胞，CBS 777.84、ATCC 58643、CBS 101039、PC10和PEC1菌株的游动孢子活力显著降低。此外，1μg/ml PIA诱导的中性粒细胞使ATCC 58643、CBS 101039和PC10菌株的游动孢子活力显著降低。然而，更高剂量的PIA（10μg/ml）在降低所有6株菌株的游动孢子活力方面并未显示出优势。我们的研究结果表明，PIA免疫疗法可提高中性粒细胞的游动孢子杀伤活性，中性粒细胞可能参与了PIA免疫疗法有益效果的前沿机制。
