Human Adipose-Derived Mesenchymal Stem Cells Colonize and Promote Healing of Leprosy Ulcer by Inducing Neuro-Vascularization.

Leprosy ulcer is a chronic and recurrent disease resulting from nerve injury. While existing treatments partially facilitate ulcer healing, they exhibit limited ability to address localized nerve repair, leading to a risk of recurrence. Moreover, there is a dearth of animal models to evaluate the preclinical efficacy and safety of novel therapeutic approaches. Over the years, adipose-derived mesenchymal stem cells have been extensively employed in regenerative medicine as an optimal cell therapy source for fostering skin ulcer healing. They have also demonstrated the capacity to enhance nerve regeneration in in vitro experiments and clinical trials. In this study, we established a NU/NU mouse foot pad leprosy ulcer model, transplanted human adipose-derived stem cells (hADSCs) into leprosy ulcers via local injection, and conducted subsequent follow-up. Our findings revealed that hADSCs persisted in the leprosy ulcer and facilitated the healing process. In this respect, gross observation and histological analysis revealed increased granular formation, collagen synthesis, and re-epithelialization in the local ulcer area. RNA-Seq data revealed that the upregulated differential genes resulting from the transplantation intervention were not only enriched in pathways related to re-epithelialization and collagen synthesis but also contributed to local nerve regeneration. Furthermore, immunofluorescence assays revealed the increased expression of angiogenesis markers-CD31 and VEGFa, cell proliferation markers-Ki67 and TGF-ß, and nerve regeneration markers-ß3-tubulin, SOX10, NGF, and NT-3. These results underscore the potential of hADSCs in promoting the healing of leprosy ulcers and offer valuable preclinical data for their prospective clinical application.

Occupational health effect of TCE exposure: Experiment evidence of gene-environment interaction in hypersensitivity reaction.

BACKGROUND: Recently, Trichloroethylene (TCE) induced TCE hypersensitivity syndrome (THS) has attracted the attention of many researchers in the field of environmental and occupational health. Studies have revealed that Human leukocyte antigen (HLA) polymorphisms were the important genetic determinants of the diseases, but the potential molecular mechanism remains unclear. OBJECTIVE: This study aimed to investigate the association between THS and HLA at the molecular level. METHOD: We chose the human B-lymphoblastoid cell line Hmy2.C1R transfected with cDNA of HLA-B*13:01 and HLA-B*13:02 to analyze the characteristics of HLA-B-binding peptides and investigate the effect of TCE on the binding affinity of peptides to the HLA-B molecules. Further, the mathematical model was used to identify the possible interaction between TCE and HLA-B*13:01 or HLA-B*13:02 molecule. RESULTS: 54 HLA-B*13:01-binding peptides and 85 HLA-B*13:02-binding peptides were identified. Comparing the protein sequences of HLA-B*13:01 and HLA-B*13:02, amino acids were different at positions 94, 95 and 97. The results of the binding affinity of self-peptides to HLA molecules in the presence of TCE showed that TCE significantly decreased the binding affinity of peptides to HLA-B*13:01 only, but did not affect that of HLA-B*13:02. Molecular docking model showed that there was a unique high-affinity binding mode between TCE and HLA-B*13:01 (but not HLA-B*13:02), and the binding site located in the region of F pocket, suggesting that the unique structure of the F pocket of HLA-B*13:01 might provide the possibility of binding TCE. The pathogenesis of interaction between HLA-B*13:01 and TCE might belong to the model of the alteration of the HLA-presented self-peptide repertoire. DISCUSSION: This study explored the molecular mechanism of the association between THS and HLA-B*13:01, and had important implications for understanding the role of gene-environment interaction in the development of complex environment-related diseases.

Insight into the Molecular Characteristics of Langhans Giant Cell by Combination of Laser Capture Microdissection and RNA Sequencing.

PURPOSE: The presence of Langhans giant cell (LGC) is a hallmark of mycobacterium-induced granuloma. The molecular characteristics and functions of LGC remain unclear to date. The study aimed to systematically characterize the molecular characteristics of LGC and reveal the potential functions. METHODS: Human LGCs were purified through laser capture microdissection (LCM) in vitro. RNA sequencing and in-depth transcriptome analysis were performed for purified LGCs and macrophages in the same system. Skin samples from mycobacterial infection patients were used to confirm some of the transcriptional expression. RESULTS: Human LGCs have different expression pattern from macrophages in the same in vitro system. A total of 967 differentially expressed genes were found. Bioinformatics analysis showed that LGCs are is characterized by active cell shape regulation, increased cytoskeletal components, weakened energy metabolism level, and reduced immune response. CCL7 may be a specific molecular for LGC to communicate with CCR1-expression cells in granuloma. CONCLUSION: LGCs have unique molecular characteristics different from that of macrophages. They may play a role in maintaining the hemostasis in granuloma.

Progress of the Art of Macrophage Polarization and Different Subtypes in Mycobacterial Infection.

Mycobacteriosis, mostly resulting from Mycobacterium tuberculosis (MTb), nontuberculous mycobacteria (NTM), and Mycobacterium leprae (M. leprae), is the long-standing granulomatous disease that ravages several organs including skin, lung, and peripheral nerves, and it has a spectrum of clinical-pathologic features based on the interaction of bacilli and host immune response. Histiocytes in infectious granulomas mainly consist of infected and uninfected macrophages (Mφs), multinucleated giant cells (MGCs), epithelioid cells (ECs), and foam cells (FCs), which are commonly discovered in lesions in patients with mycobacteriosis. Granuloma Mφ polarization or reprogramming is the crucial appearance of the host immune response to pathogen aggression, which gets a command of endocellular microbe persistence. Herein, we recapitulate the current gaps and challenges during Mφ polarization and the different subpopulations of mycobacteriosis.

IFI44L as a Forward Regulator Enhancing Host Antituberculosis Responses.

Interferon-induced protein 44-like (IFI44L) gene is a type I interferon-stimulated gene (ISG) that plays a critical role in antiviral activity and constitutes a promising diagnostic marker. However, its precise role and function in tuberculosis have not been unveiled. This study showed that IFI44L acts as an antimicrobial target and positive modulator in human macrophages. Knockdown of IFI44L led to increased Mycobacterium tuberculosis intracellular survival. Moreover, IFI44L was significantly upregulated, and it restricted the intracellular survival of M. tuberculosis H37Rv strains at 72 h after rifampicin treatment. Individuals with cutaneous tuberculosis (CTB) were found to have significantly higher IFI44L expression after 6 months of rifampicin therapy than after only 1 month. These results demonstrated that IFI44L induced positive regulation and clearance of M. tuberculosis from human macrophages. This antimicrobial activity of IFI44L makes it a possible target for therapeutic applications against M. tuberculosis.

Isolation of Novel Mycobacterium Species from Skin Infection in an Immunocompromised Person.

We investigated a case of cutaneous infection in an immunocompromised patient in China that was caused by a novel species within the Mycobacterium gordonae complex. Results of whole-genome sequencing indicated that some strains considered to be M. gordonae complex are actually polyphyletic and should be designated as closely related species.

Transcriptome Analysis Reveals the Molecular Immunological Characteristics of Lesions in Patients with Halo Nevi When Compared to Stable Vitiligo, Normal Nevocytic Nevi and Cutaneous Melanoma.

BACKGROUND: Given their similar appearance and histology, halo nevi (HN) were considered as a type of vitiligo. However, whether HN have stronger immune response than stable vitiligo (VL) remains unclear. In addition, the molecular alterations in HN compared with normal nevocytic nevi (NN) and primary cutaneous melanoma (MM) must be determined. This study aimed to systematically characterize the molecular immunological features of HN. METHODS: Skin samples from patients with HN, VL, NN, and MM were obtained with informed consent. Each of the four groups underwent transcriptome sequencing and data analysis were for pairwise comparison. Quantitative real-time PCR (RT-qPCR) was conducted to confirm the transcriptional expression of some differentially expressed genes (DEGs) that were closely related to immunity. RESULTS: A total of 441 and 1507 DEGs were found in the HN/NN and HN/MM groups, respectively. Compared with those of VL, HN lesions contained 162 up-regulated DEGs and 12 down-regulated DEGs. Bioinformatics analysis showed that the up-regulated genes in HN were substantially enriched in immune response, immune deficiency, and immune rejection; biological stimulation (virus, bacteria); and proliferation and activation of immune cells. Immune cell composition analysis also confirmed high expression levels of multiple immunocytes in HN. CONCLUSION: The molecular immune mechanisms of HN and VL were similar, but the immune activity of HN was stronger than that of VL. Innate and adaptive immunity were involved in the pathogenesis and progression of HN and VL.

TCF3 is epigenetically silenced by EZH2 and DNMT3B and functions as a tumor suppressor in endometrial cancer.

Endometrial cancer (EC) is the most common gynecological malignancy worldwide. However, the molecular mechanisms underlying EC progression are still largely unknown, and chemotherapeutic options for EC patients are currently very limited. In this study, we found that histone methyltransferase EZH2 and DNA methyltransferase DNMT3B were upregulated in EC samples from patients, and promoted EC cell proliferation as evidenced by assays of cell viability, cell cycle, colony formation. Mechanistically, we found that EZH2 promoted EC cell proliferation by epigenetically repressing TCF3, a direct transcriptional activator of CCKN1A (p21WAF1/Cip1), in vitro and in vivo. In addition, we found that DNMT3B specifically methylated the TCF3 promoter, repressing TCF3 expression and accelerating EC cell proliferation independently of EZH2. Importantly, elevated expression of EZH2 or DNMT3B in EC patients inversely correlated with expression of TCF3 and p21, and was associated with shorter overall survival. We show that combined treatment with GSK126 and 5-Aza-2d treatment wit synergistically inhibited methyltransferase activity of EZH2 and DNMT3B, resulting in a profound block of EC cell proliferation as well as EC tumor progression in cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. These findings reveal that TCF3 functions as a tumor suppressor epigenetically silenced by EZH2 and DNMT3B in EC, and support the notion that targeting the EZH2/DNMT3B/TCF3/p21 axis may be a novel and effective therapeutic strategy for treatment of EC.

Cellular, Molecular, and Immunological Characteristics of Langhans Multinucleated Giant Cells Programmed by IL-15.

Langhans multinucleated giant cells (LGCs) are a specific type of multinucleated giant cell containing a characteristic horseshoe-shaped ring of nuclei that are present within granulomas of infectious etiology. Although cytokines that trigger macrophage activation (such as IFN-γ) induce LGC formation, it is not clear whether cytokines that trigger macrophage differentiation contribute to LGC formation. Here, we found that IL-15, a cytokine that induces M1 macrophage differentiation, programs human peripheral blood adherent cells to form LGCs. Analysis of the IL-15‒treated adherent cell transcriptome identified gene networks for T cells, DNA damage and replication, and IFN-inducible genes that correlated with IL-15 treatment and LGC-type multinucleated giant cell formation. Gene networks enriched for myeloid cells were anticorrelated with IL-15 treatment and LGC formation. Functional studies revealed that T cells were required for IL-15‒induced LGC formation, involving a direct contact with myeloid cells through CD40L-CD40 interaction and IFN-γ release. These data indicate that IL-15 induces LGC formation through the direct interaction of activated T cells and myeloid cells.

Intact Mycobacterium leprae Isolated from Placenta of a Pregnant Woman, China.

Whether Mycobacterium leprae transmits from placenta to fetus remains unknown. We describe the case of a pregnant woman with untreated histoid leproma. Although her newborn was healthy, laboratory examination revealed intact M. leprae present in the placenta, suggesting that the placental barrier might prevent vertical dissemination of M. leprae.

Landscape of the genome and host cell response of Mycobacterium shigaense reveals pathogenic features.

A systems approach was used to explore the genome and transcriptome of Mycobacterium shigaense, a new opportunistic pathogen isolated from a patient with a skin infection, and the host response transcriptome was assessed using a macrophage infection model. The M. shigaense genome comprises 5,207,883 bp, with 67.2% G+C content and 5098 predicted coding genes. Evolutionarily, the bacterium belongs to a cluster in the phylogenetic tree along with three target opportunistic pathogenic strains, namely, M. avium, M. triplex and M. simiae. Potential virulence genes are indeed expressed by M. shigaense under culture conditions. Phenotypically, M. shigaense had similar infection and replication capacities in a macrophage model as the opportunistic species compared to M. tuberculosis. M. shigaense activated NF-κB, TNF, cytokines and chemokines in the host innate immune-related signaling pathways and elicited an early response shared with pathogenic bacilli except M. tuberculosis. M. shigaense upregulated specific host response genes such as TLR7, CCL4 and CXCL5. We performed an integrated and comparative analysis of M. shigaense. Multigroup comparison indicated certain differences with typical pathogenic bacilli in terms of gene features and the macrophage response.

Mycobacterium gordonae in Patient with Facial Ulcers, Nosebleeds, and Positive T-SPOT.TB Test, China.

Mycobacterium gordonae is often regarded as a weak pathogen that only occasionally causes overt disease. We report a case of M. gordonae infection in the facial skin, nasal mucosa, and paranasal sinus in an immunocompetent patient and review previous cases. The T-SPOT.TB test might be useful in diagnosing such cases.