Analysis of the components of Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg) and its regulation of γδ T-cell function.

BACKGROUND: Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg) is a peptide antigen released from the mycobacterial cytoplasm into the supernatant of Mycobacterium tuberculosis (Mtb) attenuated H37Ra strain after autoclaving at 121 °C for 20 min. Mtb-HAg can specifically induce γδ T-cell proliferation in vitro. However, the exact composition of Mtb-HAg and the protein antigens that are responsible for its function are currently unknown. METHODS: Mtb-HAg extracted from the Mtb H37Ra strain was subjected to LC‒MS mass spectrometry. Twelve of the identified protein fractions were recombinantly expressed in Escherichia coli by genetic engineering technology using pET-28a as a plasmid and purified by Ni-NTA agarose resin to stimulate peripheral blood mononuclear cells (PBMCs) from different healthy individuals. The proliferation of γδ T cells and major γδ T-cell subset types as well as the production of TNF-α and IFN-γ were determined by flow cytometry. Their proliferating γδ T cells were isolated and purified using MACS separation columns, and Mtb H37Ra-infected THP-1 was co-cultured with isolated and purified γδ T cells to quantify Mycobacterium viability by counting CFUs. RESULTS: In this study, Mtb-HAg from the attenuated Mtb H37Ra strain was analysed by LC‒MS mass spectrometry, and a total of 564 proteins were identified. Analysis of the identified protein fractions revealed that the major protein components included heat shock proteins and Mtb-specific antigenic proteins. Recombinant expression of 10 of these proteins in by Escherichia coli genetic engineering technology was used to successfully stimulate PBMCs from different healthy individuals, but 2 of the proteins, EsxJ and EsxA, were not expressed. Flow cytometry results showed that, compared with the IL-2 control, HspX, GroEL1, and GroES specifically induced γδ T-cell expansion, with Vγ2δ2 T cells as the main subset, and the secretion of the antimicrobial cytokines TNF-α and IFN-γ. In contrast, HtpG, DnaK, GroEL2, HbhA, Mpt63, EsxB, and EsxN were unable to promote γδ T-cell proliferation and the secretion of TNF-α and IFN-γ. None of the above recombinant proteins were able to induce the secretion of TNF-α and IFN-γ by αß T cells. In addition, TNF-α, IFN-γ-producing γδ T cells inhibit the growth of intracellular Mtb. CONCLUSION: Activated γδ T cells induced by Mtb-HAg components HspX, GroES, GroEL1 to produce TNF-α, IFN-γ modulate macrophages to inhibit intracellular Mtb growth. These data lay the foundation for subsequent studies on the mechanism by which Mtb-HAg induces γδ T-cell proliferation in vitro, as well as the development of preventive and therapeutic vaccines and rapid diagnostic reagents.

Immune responses induced by Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg) upon co-administration with Bacillus Calmette-Guérin in mice.

OBJECTIVES: To preliminarily assess the immunogenicity of Mtb-HAg in mice and the synergistic effect provided by HAg when co-immunised with BCG. METHODS: Mice were randomly grouped for different immunisations and then spleens were aseptically removed and lymphocytes were extracted for immediate detection of cytokines transcript levels and stimulation index(SI), cytokine secretion and multifunctional antigen-specific T cells were detected after incubation for different times. RESULTS: HAg extracted from active Mtb is a group of mixed polypeptides with molecular weights of (10-14) kDa. It can significantly stimulate lymphocytes proliferation and increase SI. Injection of HAg alone and in combination with BCG induced significantly higher numbers of multifunctional antigen-specific T cells including CD4+ IFN-γ+, CD4+ IL-2+, CD8+ IFN-γ+, and CD8+ IL-2+ cells than that in BCG-treated mice. Co-immunisation induced the secretion of higher levels of IFN-γ, TNF-α, IL-2 and IL-4 and increased their mRNA expression levels. Significant increases in the transcription levels of IL-10, IL-12 and IL-17 were observed in the co-immunised group with the assistance of HAg. CONCLUSION: We demonstrated that HAg has favourable immunogenicity, triggers a stronger Th1-type immune response and proposed the hypothesis that HAg can be used as a BCG booster to further enhance the benefits of BCG.

Single-nucleus RNA sequencing reveals that macrophages and smooth muscle cells promote carotid atherosclerosis progression through mitochondrial autophagy.

Carotid atherosclerotic plaques are the manifestation of atherosclerosis in the carotid arteries and can significantly increase the incidence of cerebrovascular disease. Macrophages and smooth muscle cells are crucial for their development. To reveal the mechanism of carotid atherosclerotic plaque formation, we performed single-nucleus RNA sequencing of the carotid plaque tissue and identified 11 cell types, and the macrophages were divided into 5 different macrophage subpopulations. The macrophages and smooth muscle cells in the patients with symptomatic carotid atherosclerotic plaques caused intraplaque cell death via the mitochondrial autophagic pathway, resulting in plaque instability and rupture, which in turn led to clinical cardiovascular and cerebrovascular events. The findings provide new insights into carotid atherosclerosis formation, and this may provide new directions for the prevention and treatment of carotid atherosclerosis.

A machine learning-based prediction model for postoperative delirium in cardiac valve surgery using electronic health records.

BACKGROUND: Previous models for predicting delirium after cardiac surgery remained inadequate. This study aimed to develop and validate a machine learning-based prediction model for postoperative delirium (POD) in cardiac valve surgery patients. METHODS: The electronic medical information of the cardiac surgical intensive care unit (CSICU) was extracted from a tertiary and major referral hospital in southern China over 1 year, from June 2019 to June 2020. A total of 507 patients admitted to the CSICU after cardiac valve surgery were included in this study. Seven classical machine learning algorithms (Random Forest Classifier, Logistic Regression, Support Vector Machine Classifier, K-nearest Neighbors Classifier, Gaussian Naive Bayes, Gradient Boosting Decision Tree, and Perceptron.) were used to develop delirium prediction models under full (q = 31) and selected (q = 19) feature sets, respectively. RESULT: The Random Forest classifier performs exceptionally well in both feature datasets, with an Area Under the Curve (AUC) of 0.92 for the full feature dataset and an AUC of 0.86 for the selected feature dataset. Additionally, it achieves a relatively lower Expected Calibration Error (ECE) and the highest Average Precision (AP), with an AP of 0.80 for the full feature dataset and an AP of 0.73 for the selected feature dataset. To further evaluate the best-performing Random Forest classifier, SHAP (Shapley Additive Explanations) was used, and the importance matrix plot, scatter plots, and summary plots were generated. CONCLUSIONS: We established machine learning-based prediction models to predict POD in patients undergoing cardiac valve surgery. The random forest model has the best predictive performance in prediction and can help improve the prognosis of patients with POD.

Transcriptional analysis of human peripheral blood mononuclear cells stimulated by Mycobacterium tuberculosis antigen.

Background: Mycobacterium tuberculosis antigen (Mtb-Ag) is a polypeptide component with a molecular weight of 10-14 kDa that is obtained from the supernatant of the H37Ra strain after heat treatment. It stimulates the activation and proliferation of γδT cells in the blood to produce an immune response against tuberculosis. Mtb-Ag is therefore crucial for classifying and detecting the central genes and key pathways involved in TB initiation and progression. Methods: In this study, we performed high-throughput RNA sequencing of peripheral blood mononuclear cells (PBMC) from Mtb-Ag-stimulated and control samples to identify differentially expressed genes and used them for gene ontology (GO) and a Kyoto Encyclopedia of Genomes (KEGG) enrichment analysis. Meanwhile, we used PPI protein interaction network and Cytoscape analysis to identify key genes and qRT-PCR to verify differential gene expression. Single-gene enrichment analysis (GSEA) was used further to elucidate the potential biological functions of key genes. Analysis of immune cell infiltration and correlation of key genes with immune cells after Mtb-Ag-stimulated using R language. Results: We identified 597 differentially expressed genes in Mtb-Ag stimulated PBMCs. KEGG and GSEA enrichment analyzed the cellular pathways related to immune function, and DEGs were found to be primarily involved in the TNF signaling pathway, the IL-17 signaling pathway, the JAK-STAT signaling pathway, cytokine-cytokine receptor interactions, and the NF-κB signaling pathway. Wayne analysis using GSEA, KEGG, and the protein-protein interaction (PPI) network showed that 34 genes, including PTGS2, IL-1ß, IL-6, TNF and IFN-γ et al., were co-expressed in the five pathways and all were up-regulated by Mtb-Ag stimulation. Twenty-four DEGs were identified using qRT-PCR, including fourteen up-regulated genes (SERPINB7, IL20, IFNG, CSF2, PTGS2, TNF-α, IL36G, IL6, IL10, IL1A, CXCL1, CXCL8, IL4, and CXCL3) and ten down-regulated genes (RTN1, CSF1R CD14, C5AR1, CXCL16, PLXNB2, OLIG1, EEPD1, ENG, and CCR1). These findings were consistent with the RNA-Seq results. Conclusion: The transcriptomic features associated with Mtb-Ag provide the scientific basis for exploring the intracellular immune mechanisms against Mtb. However, more studies on these DEGs in pathways associated with Mtb-Ag stimulation are needed to elucidate the underlying pathologic mechanisms of Mtb-Ag during Mtb infection.

Safety and feasibility of the transoral endoscopic thyroidectomy vestibular approach with neuroprotection techniques for papillary thyroid carcinoma.

BACKGROUND: This study aimed to evaluate the feasibility and safety of the trans-oral endoscopic thyroidectomy vestibular approach (TOETVA) with neuroprotection techniques for the surgical management of papillary thyroid carcinoma (PTC). METHODS: Patients with PTC who underwent TOETVA between December 2016 and July 2020 were included in this study, and their relevant clinical characteristics, operational details, and surgical outcomes were reviewed and extracted from their medical records for further analysis. RESULTS: A total of 75 patients successfully underwent TOETVA with zero conversions. Unilateral lobectomy with isthmectomy and total thyroidectomy were completed for 58 and 17 patients, respectively, all using our unique neuroprotective procedure and ipsilateral central neck dissection (CND). The mean number of retrieved lymph nodes versus positive lymph nodes was 6.8 ± 3.7 vs. 1.5 ± 2.3. Postoperative complications included three cases of transient superior laryngeal nerve (SLN) palsy (4.0%), five cases of transient recurrent laryngeal nerve (RLN) palsy (6.7%), 14 cases of transient hypoparathyroidism (18.7%), two cases of numb chin (2.7%) and two cases of flap perforation (2.7%). The follow-up period for patients with PTC lasted for 15.6 ± 10.9 months, during which no other complications or tumor recurrence were observed. CONCLUSION: TOETVA can be safely performed for patients with PTC with satisfactory results during the short-term follow-up period. Our neuroprotection techniques can be integrated into TOETVA, which is worth recommending for PTC patients who desire better cosmetic surgical outcomes.

Qin's seven steps for endoscopic selective lateral neck dissection via the chest approach in patients with papillary thyroid cancer: experience of 35 cases.

BACKGROUND: Endoscopic thyroidectomy is widely performed as it does not result in neck scar. However, there is a paucity of reports pertaining to completely endoscopic lateral neck dissection (LND). In this study, we introduce our step-wise approach for performing endoscopic selective LND via the chest-breast approach. We refer to this approach as Qin's seven steps. METHODS: The Qin's seven steps are: (1) establishment of working space range; (2) dissection of lymph nodes between the SCM and the sternohyoid muscle (level IV) and exposure of omohyoid; (3) dissection of lymph nodes at level IV; (4) dissection of lymph nodes at level III; (5) dissection of lymph nodes at carotid triangle (level III); (6) exposure of accessory nerve and dissection of lymph nodes at level II a; (7) dissection of lymph nodes at level II b. We reviewed the clinical data of 35 patients with papillary thyroid cancer (PTC) who were operated using the Qin's seven steps. RESULTS: All 35 patients successfully underwent LND; bilateral LND was performed in 5 patients. The mean tumor size was 1.8 ± 1.0 cm; seven patients had multiple lesions. The mean number of retrieved lymph nodes in level II, III and IV were 8.8 ± 5.6, 6.1 ± 4.0 and 9.3 ± 5.1, respectively. As for complications, there were 3 cases of accessory nerve injury and 1 case of hypoglossal nerve injury. Internal jugular vein injury, cervical plexus injury and lymphatic leakage occurred in 2, 7, and 1 patients, respectively. CONCLUSION: The Qin's seven steps for performing endoscopic selective LND could be safely used in PTC patients with lateral lymph node metastasis. Satisfactory results were achieved in the short-term follow-up period. We recommend the use of Qin's seven steps for PTC patients who are not desirous of neck scar.

Improvement of cerebral ischemia/reperfusion injury by daucosterol palmitate-induced neuronal apoptosis inhibition via PI3K/Akt/mTOR signaling pathway.

Traditional Chinese medicine has growing importance in the treatment of ischemia stroke due to its abundance and low drug resistance. In this study, we aim to investigate the therapeutic potential of daucosterol palmitate against ischemia stroke, as well as its neuro-protective mechanism. The dose-response effects of daucosterol palmitate in the protection from brain damage were evaluated in a cerebral ischemia/reperfusion (I/R) rat model. The correlation of neuro-protective effects of daucosterol palmitate with apoptosis inhibition was examined and the possible signaling targets were identified. Our findings revealed that daucosterol palmitate treatment after 2 h' ischemia significantly lowered brain damage, and neuronal cell apoptosis caused by I/R injury in a dose-response mode (20, 40 and 80 mg/kg). Western blot analysis indicated that daucosterol palmitate could reverse the effects of I/R injury on protein expression of PI3K and mTOR, and phosphorylation of Akt. Contrarily, inactivation of PI3K using wortmannin dramatically antagonized the effect of daucosterol palmitate for I/R injury. With these findings, it supports the application potential of daucosterol palmitate in the treatment of ischemia stroke. Besides, the PI3K/Akt/mTOR pathway might be potential cellular targets for daucosterol palmitate.