Hang Nguyen Thi Le, Hijikata Minako, Maeda Shinji, Thuong Pham Huu, Huan Hoang Van, Hoang Nguyen Phuong, Tam Do Bang, Anh Pham Thu, Huyen Nguyen Thu, Cuong Vu Cao, Kobayashi Nobuyuki, Wakabayashi Keiko, Miyabayashi Akiko, Seto Shintaro, Keicho Naoto
NCGM-BMH Medical Collaboration Center, Hanoi, Vietnam.
Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, JATA, Tokyo, Japan.
Front Microbiol. 2023 Jul 4;14:1187390. doi: 10.3389/fmicb.2023.1187390. eCollection 2023.
It is assumed that host defense systems eliminating the pathogen and regulating tissue damage make a strong impact on the outcome of tuberculosis (TB) disease and that these processes are affected by rifampicin (RIF) resistance-conferring mutations of (Mtb). However, the host responses to the pathogen harboring different mutations have not been studied comprehensively in clinical settings. We analyzed clinico-epidemiological factors and blood transcriptomic signatures associated with major mutations conferring RIF resistance in a cohort study.
Demographic data were collected from 295 active pulmonary TB patients with treatment history in Hanoi, Vietnam. When recruited, drug resistance-conferring mutations and lineage-specific variations were identified using whole-genome sequencing of clinical Mtb isolates. Before starting retreatment, total RNA was extracted from the whole blood of HIV-negative patients infected with Mtb that carried either the H445Y or S450L mutation, and the total RNA was subjected to RNA sequencing after age-gender matching. The individual RNA expression levels in the blood sample set were also measured using real-time RT-PCR. Logistic and linear regression models were used to assess possible associations.
In our cohort, S450L and H445Y were major RIF resistance-conferring mutations [32/87 (36.8%) and 15/87 (17.2%), respectively]. H445Y was enriched in the ancient Beijing genotype and was associated with nonsynonymous mutations of Rv1830 that has been reported to regulate antibiotic resilience. H445Y was also more frequently observed in genetically clustered strains and in samples from patients who had received more than one TB treatment episode. According to the RNA sequencing, gene sets involved in the interferon-γ and-α pathways were downregulated in H445Y compared with S450L. The qRT-PCR analysis also confirmed the low expression levels of interferon-inducible genes, including and , in the H445Y group, particularly in patients with extensive lesions on chest X-ray.
Our study results showed that mutations as well as Mtb sublineage with additional genetic variants may have significant effects on host response. These findings strengthen the rationale for investigation of host-pathogen interactions to develop countermeasures against epidemics of drug-resistant TB.
一般认为，宿主防御系统在清除病原体和调节组织损伤方面对结核病（TB）的病情转归有重大影响，并且这些过程会受到结核分枝杆菌（Mtb）利福平（RIF）耐药性相关突变的影响。然而，在临床环境中，宿主对携带不同突变的病原体的反应尚未得到全面研究。我们在一项队列研究中分析了与主要RIF耐药性相关突变相关的临床流行病学因素和血液转录组特征。
收集了越南河内295例有治疗史的活动性肺结核患者的人口统计学数据。招募时，通过对临床Mtb分离株进行全基因组测序，鉴定出耐药性相关突变和谱系特异性变异。在开始再治疗前，从感染携带H445Y或S450L突变的Mtb的HIV阴性患者的全血中提取总RNA，并在年龄和性别匹配后对总RNA进行RNA测序。还使用实时RT-PCR测量血液样本组中的个体RNA表达水平。使用逻辑回归和线性回归模型评估可能的关联。
在我们的队列中，S450L和H445Y是主要的RIF耐药性相关突变[分别为32/87（36.8%）和15/87（17.2%）]。H445Y在古老的北京基因型中富集，并且与据报道可调节抗生素耐受性的Rv1830的非同义突变相关。H44在基因聚集菌株以及接受过不止一次结核病治疗的患者样本中也更频繁地被观察到。根据RNA测序，与S450L相比，H445Y中参与干扰素-γ和-α途径的基因集下调。qRT-PCR分析也证实了H445Y组中干扰素诱导基因（包括和）的低表达水平，特别是在胸部X线有广泛病变的患者中。
我们的研究结果表明，突变以及具有其他遗传变异的Mtb亚谱系可能对宿主反应有显著影响。这些发现强化了研究宿主-病原体相互作用以制定抗耐药结核病流行对策的理论依据。
