Dinesh Shreya, Prajna Lalitha, Venkatesh Prajna Namperumalsamy, Dharmalingam Kuppamuthu, Devarajan Bharanidharan
Department of Microbiology and Bioinformatics, Aravind Medical Research Foundation, Madurai, India.
Department of Biomedical Sciences, Madurai Kamaraj University, Madurai, India.
Front Cell Infect Microbiol. 2025 May 30;15:1560628. doi: 10.3389/fcimb.2025.1560628. eCollection 2025.
Fungal keratitis, caused primarily by spp. and , is a significant cause of corneal blindness, particularly in tropical regions. Current antifungal agents like natamycin and voriconazole have limited efficacy, underscoring the need for a deeper understanding of host immune responses.
This study employed high-throughput RNA sequencing to investigate differential gene expression in human corneal tissues from patients with spp. and keratitis and compared them to control cadaver corneal samples. RNA was extracted from infected and control samples, followed by sequencing and differential expression analysis. Further confirmation of differential expression of selected genes were carried out by Real-Time quantitative PCR (RT-qPCR).
Data analysis identified common and spp. and -specific differentially expressed genes (DEGs). Pathway enrichment analysis using common genes identified pathways enriched in both infections, such as interleukin 17 (IL-17), tumor necrosis factor (TNF), and chemokine signalling. Expression of hub genes, including S100 calcium binding protein A7 (S100A7), S100 calcium binding protein A8 (S100A8), S100 calcium binding protein A9 (S100A9) and C-X-C motif chemokine ligand 8 (CXCL8), identified in interleukin 17 (IL-17) signalling, was confirmed by RT-qPCR analysis. spp.-specific DEGs, including complement C3 (C3), interleukin 6 (IL-6), interleukin 19 (IL-19) and leucine rich alpha-2-glycoprotein 1 (LRG1), are enriched in pathways such as positive regulation of immune responses, acute inflammatory responses, leukocyte cell-cell adhesion, and the regulation of cell-cell adhesion. -specific DEGs, such as triggering receptor expressed on myeloid cells 2 (TREM2) and apolipoprotein E (APOE), are predominantly enriched in adaptive immune response, negative regulation of immune system process, negative regulation of immune response, cell migration and motility pathways.
RT-qPCR confirmed the key pathogen-specific DEGs, highlighting their potential as biomarkers for pathogen-specific immune responses. These findings provide insights into the distinct immune pathways triggered by spp. and , offering new therapeutic targets for improving fungal keratitis treatment.
真菌性角膜炎主要由 spp. 和 引起，是导致角膜盲的重要原因，在热带地区尤为如此。目前的抗真菌药物如那他霉素和伏立康唑疗效有限，这凸显了深入了解宿主免疫反应的必要性。
本研究采用高通量RNA测序技术，调查 spp. 和 性角膜炎患者角膜组织中的差异基因表达，并将其与对照尸体角膜样本进行比较。从感染样本和对照样本中提取RNA，随后进行测序和差异表达分析。通过实时定量PCR（RT-qPCR）对选定基因的差异表达进行进一步验证。
数据分析确定了 spp. 和 共有的以及各自特有的差异表达基因（DEG）。使用共有基因进行的通路富集分析确定了在两种感染中均富集的通路，如白细胞介素17（IL-17）、肿瘤坏死因子（TNF）和趋化因子信号通路。RT-qPCR分析证实了在白细胞介素17（IL-17）信号通路中鉴定出的枢纽基因的表达，包括S100钙结合蛋白A7（S100A7）、S100钙结合蛋白A8（S100A8）、S100钙结合蛋白A9（S100A9）和C-X-C基序趋化因子配体8（CXCL8）。 spp. 特有的DEG，包括补体C3（C3）、白细胞介素6（IL-6）、白细胞介素19（IL-19）和富含亮氨酸的α-2-糖蛋白1（LRG1），在免疫反应的正调控、急性炎症反应、白细胞细胞间粘附以及细胞间粘附的调控等通路中富集。 特有的DEG，如髓系细胞触发受体2（TREM2）和载脂蛋白E（APOE），主要富集在适应性免疫反应、免疫系统过程的负调控、免疫反应的负调控、细胞迁移和运动通路中。
RT-qPCR证实了关键的病原体特异性DEG，突出了它们作为病原体特异性免疫反应生物标志物的潜力。这些发现为 spp. 和 引发的不同免疫通路提供了见解，为改善真菌性角膜炎治疗提供了新的治疗靶点。
