Roy Madhurima, Bagchi Aniruddha, Karmakar Chaitali, Chatterjee Mitali
Department of Pharmacology, Institute of Postgraduate Medical Education and Research (IPGME&R), Kolkata, India.
Infect Immun. 2025 Jun 10;93(6):e0040924. doi: 10.1128/iai.00409-24. Epub 2025 May 9.
Neutrophil transdifferentiation involves the acquisition of dendritic cell-like properties, challenging the traditional view of neutrophils being solely phagocytes. The presence of transdifferentiated neutrophils is established in Visceral Leishmaniasis, but not in its dermal sequel, Post Kala-azar Dermal Leishmaniasis. Accordingly, this study investigated the altered functionalities of neutrophils focusing on the acquisition of dendritic cell-like properties and its impact on infection establishment. In PKDL cases, immunophenotyping of neutrophil-dendritic cells (N-DC hybrids) was performed using flow cytometry, along with studying the status of N-DC hybrid inducing cytokines (TNF-α, IFN-γ) and growth factor (GM-CSF). infection of neutrophils with was monitored by droplet digital PCR, employing ; additionally, their frequency of transdifferentiation, oxidative and phagocytic status, as well as apoptosis potential were quantified by flow cytometry. Compared with healthy controls, neutrophils from PKDL cases demonstrated a significant upregulation of CD83 positivity, but the frequency of co-stimulation (HLA-DR, CD80/86) was unaltered. PKDL cases demonstrated raised levels of TNF-α and IFN-γ, but GM-CSF remained unchanged. Following infection of neutrophils, infection was evident at 2 h and was accompanied by CD83 positivity. Furthermore, the CD66b/CD83 vis CD66b/CD83 subset exhibited heightened generation of reactive oxygen species (ROS), enhanced phagocytosis, and increased apoptosis. Taken together, neutrophils from PKDL cases demonstrated transdifferentiation with the absence of antigen-presenting function. Virulent induced transdifferentiation in neutrophils, altering their functionalities and facilitating parasite uptake, along with heightened generation of intra-neutrophilic ROS and enhanced apoptosis, which possibly facilitated their engulfment by macrophages, thereby bolstering the "Trojan horse" mechanism of parasite transfer.
中性粒细胞转分化涉及获得树突状细胞样特性，这对中性粒细胞仅是吞噬细胞的传统观点提出了挑战。在内脏利什曼病中已证实存在转分化的中性粒细胞，但在其皮肤后遗症——黑热病后皮肤利什曼病中则未发现。因此，本研究聚焦于中性粒细胞获得树突状细胞样特性及其对感染建立的影响，调查了中性粒细胞功能的改变。在黑热病后皮肤利什曼病病例中，使用流式细胞术对中性粒细胞 - 树突状细胞（N - DC 杂交细胞）进行免疫表型分析，同时研究 N - DC 杂交细胞诱导细胞因子（TNF -α、IFN -γ）和生长因子（GM - CSF）的状态。通过液滴数字 PCR 监测中性粒细胞感染，采用[具体方法未给出]；此外，通过流式细胞术对其转分化频率、氧化和吞噬状态以及凋亡潜能进行定量分析。与健康对照相比，黑热病后皮肤利什曼病病例的中性粒细胞 CD83 阳性显著上调，但共刺激（HLA - DR、CD80/86）频率未改变。黑热病后皮肤利什曼病病例中 TNF -α和 IFN -γ水平升高，但 GM - CSF 保持不变。中性粒细胞感染[病原体未明确]后，2 小时出现感染，并伴有 CD83 阳性。此外，CD66b/CD83 相对于 CD66b/CD83 亚群表现出活性氧（ROS）生成增加、吞噬作用增强和凋亡增加。综上所述，黑热病后皮肤利什曼病病例的中性粒细胞表现出转分化但缺乏抗原呈递功能。强毒力的[病原体未明确]诱导中性粒细胞转分化，改变其功能并促进寄生虫摄取，同时增加细胞内 ROS 生成和增强凋亡，这可能促进巨噬细胞对它们的吞噬，从而加强寄生虫转移的“特洛伊木马”机制。
