Peng Zhangli, Xu Chao, You Taixian, Shu Chengjie, Li Qing, Li Nana, He Renzhong, Chen Ling, Xu Lin
Tuberculosis Division of Pulmonary and Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.
Department of General Practice, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China.
Front Cell Infect Microbiol. 2025 Sep 2;15:1592296. doi: 10.3389/fcimb.2025.1592296. eCollection 2025.
(Mtb) modulates macrophage polarization to evade host immunity and enhance intracellular survival. Rv3737, a probable conserved transmembrane protein in Mtb, has an unclear biological function. This study investigates the role of Rv3737 in regulating macrophage polarization and Mtb survival within host cells.
The structure of Rv3737 was predicted using bioinformatics tools. Macrophage polarization markers were assessed by real-time PCR for M1/M2-associated cytokines, and flow cytometry for CD86/CD206 expression. RNA sequencing, along with KEGG and GO analyses, was used to explore underlying regulatory pathways. Western blotting evaluated the phosphorylation status of NF-κB (P65, IκB) and MAPK (ERK, P38, JNK) signaling components. Colony-forming units (CFUs) and inducible nitric oxide synthase (iNOS) levels were examined in H37RvΔRv3737-infected macrophages pretreated with specific inhibitors (JSH-23, U0126-EtOH, SB203580, SP600125).
Rv3737 is predicted to contain 10 transmembrane segments enriched in aliphatic amino acids. Deletion of Rv3737 in H37Rv (H37RvΔRv3737) led to upregulation of M1 markers (TNF-α, IL-1β, IL-6, iNOS, MCP-1, CD86) and downregulation of M2 markers (Arg-1, IL-10, TGF-β, CD206). Conversely, overexpression of Rv3737 (MS_Rv3737) promoted M2 polarization. RNA sequencing indicated NF-κB pathway activation in macrophages infected with H37RvΔRv3737, along with increased phosphorylation of P65, IκB, ERK, and P38. Inhibition of NF-κB (with JSH-23) and P38 MAPK (with SB203580) reduced iNOS levels and partially restored Mtb survival, indicating that Rv3737 deletion enhances the macrophage antimicrobial response.
Rv3737 suppresses M1 macrophage polarization to promote Mtb survival. Its deletion enhances host antimicrobial activity by activating NF-κB and MAPK signaling pathways. Targeting Rv3737 may represent a novel strategy for tuberculosis therapy.
结核分枝杆菌（Mtb）调节巨噬细胞极化以逃避宿主免疫并增强细胞内存活能力。Rv3737是Mtb中一种可能保守的跨膜蛋白，其生物学功能尚不清楚。本研究调查Rv3737在调节巨噬细胞极化和宿主细胞内Mtb存活中的作用。
使用生物信息学工具预测Rv3737的结构。通过实时PCR检测M1/M2相关细胞因子评估巨噬细胞极化标志物，通过流式细胞术检测CD86/CD206表达。利用RNA测序以及KEGG和GO分析探索潜在的调控途径。蛋白质印迹法评估NF-κB（P65、IκB）和MAPK（ERK、P38、JNK）信号成分的磷酸化状态。在用特异性抑制剂（JSH-23、U0126-EtOH、SB203580、SP600125）预处理的H37RvΔRv3737感染的巨噬细胞中检测集落形成单位（CFU）和诱导型一氧化氮合酶（iNOS）水平。
预测Rv3737含有10个富含脂肪族氨基酸的跨膜片段。H37Rv中Rv3737缺失（H37RvΔRv3737）导致M1标志物（TNF-α、IL-1β、IL-6、iNOS、MCP-1、CD86）上调以及M2标志物（Arg-1、IL-10、TGF-β、CD206）下调。相反，Rv3737过表达（MS_Rv3737）促进M2极化。RNA测序表明H37RvΔRv3737感染的巨噬细胞中NF-κB途径激活，同时P65、IκB、ERK和P38的磷酸化增加。抑制NF-κB（用JSH-23）和P38 MAPK（用SB203580）降低iNOS水平并部分恢复Mtb存活，表明Rv3737缺失增强巨噬细胞抗菌反应。
Rv3737抑制M1巨噬细胞极化以促进Mtb存活。其缺失通过激活NF-κB和MAPK信号通路增强宿主抗菌活性。靶向Rv3737可能代表一种结核病治疗的新策略。
