Project description:The immunologic features of nontuberculous mycobacterial pulmonary disease (NTM-PD) are largely unclear. This study investigated the immunologic features of NTM-PD using digital spatial profiling techniques. Lung tissues obtained from six patients with NTM-PD between January 1, 2006, and December 31, 2020, at Seoul National University Hospital were subjected to RNA sequencing. Cores from the peribronchial and fibrotic stromal areas were stained with CD3, CD68, and DNASyto13, and gene expression at the whole-transcriptome level was quantified using PCR amplification and Illumina sequencing. Lung tissues from four patients with bronchiectasis collected during the same period were used as controls. The RNA sequencing results were validated using immunohistochemistry (IHC) in another cohort (30 patients with NTM-PD and 15 patients with bronchiectasis). NTM-PD exhibited distinct gene expression patterns in T cells and macrophages. Gene set enrichment analysis revealed that pathways related to antigen presentation and processing were upregulated in NTM-PD, particularly in macrophages. Macrophages were more prevalent and the expression of genes associated with the M1 phenotype (CD40 and CD80) was significantly elevated. Although macrophages were activated in the NTM-PD group T cell activity was unaltered. Notably, expression of the costimulatory molecule CD28 was decreased in NTM-PD. IHC analysis showed that T cells expressing Foxp3 or TIM-3, which facilitate the regulatory functions of T cells, were increased. From these, NTM-PD exhibits distinct immunologic signatures characterized by the activation of macrophages without T cell activation.
Project description:We sought to elucidate the differentially expressed host factors in bronchoalveolar lavage cells (BALc) from nontuberculous mycobacteria (NTM)-infected subjects by studying the host transcriptome in during infection. A heatmap was created from the normalized expression of selected genes that showed statistically significant differential expression between NTM-infected and uninfected subjects. Genes with similar expression patterns were grouped and the most highly expressed genes are shown. One of the most differentially expressed gene in the NTM-infected group was the CFD (complement factor D) gene. Of note, a statistically significant three-fold increase in expression of the CAMP gene, encoding the LL-37 peptide was observed in the NTM-infected subject group (padj=0.05).
Project description:Background: Patients with cystic fibrosis (CF) have an elevated lifetime risk of infection and disease caused by nontuberculous mycobacteria (NTM). Currently, there is no method to predict whether patients with cystic fibrosis will develop disease related to non-tuberculous mycobacteria. In non cystic fibrosis populations, several genetic susceptibility factors have been described. In this study, we examined whether patients with cystic fibrosis demonstrate a similar pattern of genetic susceptibility and explored host immune-related biomarkers predictive of NTM pulmonary disease (NTM-PD). Methods: We evaluated whole blood gene expression using bulk RNA-seq in a cohort of CF patients at the time of first isolation of NTM. Differential gene expression was compared in patients who did (n = 12) vs. did not (n= 30) develop NTM-PD following first NTM growth. Results: No differences in demographics or composition of white blood cell sample populations at the time of sample collection were identified between groups. There were no significant differences in the expression of genes previously reported to confer susceptibility to NTM-PD in non-CF populations. However, CF patients who went on to develop NTM-PD had higher expression of genes involved in the interferon ( and ), tumor necrosis factor, and IL6 STAT3 JAK pathways. Conclusion: Patients with CF who develop NTM-PD have increased expression of genes involved in innate immunity, in contrast to non-CF populations where these responses seem to be suppressed.
Project description:Bacille Calmette Guerin (BCG) is the only licensed vaccine against Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) disease. However, BCG has limited efficacy, necessitating the development of better vaccines. Non-tuberculous mycobacteria (NTM), a distinct lineage from Mtb, are opportunistic pathogens present in the environment. TB endemic countries experience higher exposure to NTM, but previous studies have not elucidated the relationship between NTM exposure and BCG efficacy. Therefore, we developed a mouse model (BCG+NTM) that mimics human BCG vaccination at an early stage and continuous NTM exposure via the oral route, including during TB infection. Our results show that BCG+NTM mice had improved protection against pulmonary TB correlating with increased pulmonary influx of B-cells, higher titers of anti-Mtb IgA and IgG antibodies in serum and airways, compared to mice vaccinated with BCG alone. Notably, the lungs of BCG+NTM mice developed B-cell aggregates expressing markers of germinal center formation as determined by spatial transcriptomics. We conclude a direct correlation between NTM exposure and protection from TB, with B-cells playing a crucial role.
Project description:This study aimed to examine whether nontuberculous mycobacteria (NTM) inside household showerheads are identical to those in patients with NTM-pulmonary disease (PD) since household water is one of the potential NTM sources. Samples were obtained from 32 household showerheads of patients with NTM-PD recruited through the Pulmonary Outpatient Department at the Severance Hospital between October 2018 and October 2019. All isolates from patients with NTM-PD were diagnosed using a reverse-hybridization line probe assay based on the ropB gene. To determine the mycobacterial compositions, the washing fluids were collected and investigated using multiplex polymerase chain reaction assay and NTM culture; suspected microbial isolates in these fluids and culture were identified using sequencing analysis of 16S rRNA gene. NTM species causing the PD in the patients were Mycobacterium avium, M. intracellulare, M. abscessus, M. massiliense, and M. fortuitum complex. The mycobacteria isolated from the showerhead were M. lentiflavum, M. gordonae, M. triplex, M. phocaicum, M. mucogenicum, M. florentinum, M. gilvum, M. llatzerense, and M. peregrinum. However, the species identified in the showerheads did not match those of the patients. Despite NTM species in the showerheads, clinical implications in the main pathogenesis associated with the disease in the patients studied were not elucidated.