Single-cell sequencing analysis reveals development and differentiation trajectory of Schwann cells manipulated by M. leprae.

BACKGROUND: M. leprae preferentially infects Schwann cells (SCs) in the peripheral nerves leading to nerve damage and irreversible disability. Knowledge of how M. leprae infects and interacts with host SCs is essential for understanding mechanisms of nerve damage and revealing potential new therapeutic strategies. METHODOLOGY/PRINCIPAL FINDINGS: We performed a time-course single-cell sequencing analysis of SCs infected with M. leprae at different time points, further analyzed the heterogeneity of SCs, subpopulations associated with M. leprae infection, developmental trajectory of SCs and validated by Western blot or flow cytometry. Different subpopulations of SCs exhibiting distinct genetic features and functional enrichments were present. We observed two subpopulations associated with M. leprae infection, a stem cell-like cell subpopulation increased significantly at 24 h but declined by 72 h after M. leprae infection, and an adipocyte-like cell subpopulation, emerged at 72 h post-infection. The results were validated and confirmed that a stem cell-like cell subpopulation was in the early stage of differentiation and could differentiate into an adipocyte-like cell subpopulation. CONCLUSIONS/SIGNIFICANCE: Our results present a systematic time-course analysis of SC heterogeneity after infection by M. leprae at single-cell resolution, provide valuable information to understand the critical biological processes underlying reprogramming and lipid metabolism during M. leprae infection of SCs, and increase understanding of the disease-causing mechanisms at play in leprosy patients as well as revealing potential new therapeutic strategies.

IL-23/IL-23R Promote Macrophage Pyroptosis and T Helper 1/T Helper 17 Cell Differentiation in Mycobacterial Infection.

Pathogen-induced epigenetic modifications can reshape anti-infection immune processes and control the magnitude of host responses. DNA methylation profiling has identified crucial aberrant methylation changes associated with diseases, thus providing biological insights into the roles of epigenetic factors in mycobacterial infection. In this study, we performed a genome-wide methylation analysis of skin biopsies from patients with leprosy and healthy controls. T helper 17 differentiation pathway was found to be significantly associated with leprosy through functional enrichment analysis. As a key gene in this pathway, IL-23R was found to be critical to mycobacterial immunity in leprosy, according to integrated analysis with DNA methylation, RNA sequencing, and GWASs. Functional analysis revealed that IL-23/IL-23R-enhanced bacterial clearance by activating caspase-1/GSDMD-mediated pyroptosis in a manner dependent on NLRP3 through signal transducer and activator of transcription 3 signaling in macrophages. Moreover, IL23/IL-23R promoted T helper 1 and T helper 17 cell differentiation and proinflammatory cytokine secretion, thereby increasing host bactericidal activity. IL-23R knockout attenuated the effects and increased susceptibility to mycobacterial infection mentioned earlier. These findings illustrate the biological functions of IL-23/IL-23R in modulating intracellular bacterial clearance in macrophages and further support their regulatory effects in T helper cell differentiation. Our study highlights that IL-23/IL-23R might serve as potential targets for the prevention and treatment of leprosy and other mycobacterial infections.

Case Report: Cutaneous Mycosis Caused by Purpureocillium lilacinum.

Purpureocillium lilacinum, widely used as a commercial biocontrol agent for controlling plant-parasitic nematodes, is an emerging opportunistic pathogen in humans and is increasingly reported, especially among immunocompromised patients. We report a classic case of cutaneous mycosis caused by P. lilacinum. A 51-year-old Chinese woman who received tacrolimus and glucocorticoid therapy for 3 years for nephrotic syndrome experienced recurrent papules, pustules, and ulceration on her right ring finger and subcutaneous nodules on her forearm 6 months ago. A lesion biopsy on the right ring finger revealed multiple epithelioid granulomas in the dermis and fat layer containing slender, pigmented fungal hyphae. The fungal culture showed the growth of violet floccose colonies. Lactophenol cotton blue culture stain demonstrated brush-like phialides, with a swollen basal part attached to chains of conidia. Sequencing of the internal transcribed spacer regions of ribosomal DNA, alignment with GenBank, and use of a Basic Local Alignment Search Tool analysis led to the identification of P. lilacinum. Treatment with oral voriconazole was successful.

Identification of the BTN3A3 Gene as a Molecule Implicated in Generalized Pustular Psoriasis in a Chinese Population.

The discovery of pathogenic variants provided biological insight into the role of host genetic factors in generalized pustular psoriasis (GPP). However, not all those affected by GPP carry variants in the reported genes. To comprehensively explore the molecular pathogenesis of GPP, whole-exome sequencing was performed, and two loci were identified with exome-wide significance through single variant association analysis: rs148755083 in the IL36RN gene (Pcombined = 1.19 × 10-18, OR = 8.26) and HLA-C∗06:02 within the major histocompatibility complex region (Pcombined = 8.38 × 10-12, OR = 2.98). Gene burden testing revealed that BTN3A3 correlated with GPP (Pcombined = 1.14 × 10-10, OR = 5.59). Subtype analysis showed that IL36RN and BTN3A3 were both significantly associated with GPP alone and GPP with psoriasis vulgaris, whereas a correlation with HLA-C∗06:02 was only observed in GPP with psoriasis vulgaris. Functional analysis revealed that BTN3A3 regulated cell proliferation and inflammatory balance in GPP. In particular, loss of function of BTN3A3 activated NF-κB and promoted the production of inflammatory cytokines by inhibiting IL-36Ra expression to disturb the IL-1/IL-36 inflammatory axis and enhance the TNF-α-mediated pathway. Our findings identify BTN3A3 as, to our knowledge, a previously unreported pathogenic determinant, expanding our understanding of the genetic basis of GPP.

Case of concurrence of bullous pemphigoid and Norwegian scabies.

Bullous pemphigoid (BP) with scabies is a condition rarely encountered in clinical practice, and when it is encountered, it is often due to the use of immunosuppressants. This paper is a report on a patient with BP and scabies, who developed scabs after taking dexamethasone. It should be noted that BP antibody is necessary, which can distinguish BP with scabies and bullous scabies, and the treatment options for the two diseases are different.

Artificial intelligence breast ultrasound and handheld ultrasound in the BI-RADS categorization of breast lesions: A pilot head to head comparison study in screening program.

Background: Artificial intelligence breast ultrasound diagnostic system (AIBUS) has been introduced as an alternative approach for handheld ultrasound (HHUS), while their results in BI-RADS categorization has not been compared. Methods: This pilot study was based on a screening program conducted from May 2020 to October 2020 in southeast China. All the participants who received both HHUS and AIBUS were included in the study (N = 344). The ultrasound videos after AIBUS scanning were independently watched by a senior radiologist and a junior radiologist. Agreement rate and weighted Kappa value were used to compare their results in BI-RADS categorization with HHUS. Results: The detection rate of breast nodules by HHUS was 14.83%, while the detection rates were 34.01% for AIBUS videos watched by a senior radiologist and 35.76% when watched by a junior radiologist. After AIBUS scanning, the weighted Kappa value for BI-RADS categorization between videos watched by senior radiologists and HHUS was 0.497 (p < 0.001) with an agreement rate of 78.8%, indicating its potential use in breast cancer screening. However, the Kappa value of AIBUS videos watched by junior radiologist was 0.39, when comparing to HHUS. Conclusion: AIBUS breast scan can obtain relatively clear images and detect more breast nodules. The results of AIBUS scanning watched by senior radiologists are moderately consistent with HHUS and might be used in screening practice, especially in primary health care with limited numbers of radiologists.

Comparison of the Sensititre YeastOne® and CLSI M38-A2 microdilution methods in determining the activity of nine antifungal agents against dermatophytes.

BACKGROUND: Dermatophytes are the most common fungal pathogens causing superficial infections in humans with a high prevalence worldwide. The treatment of these infections is based on the use of topical and systemic antifungal agents. A convenient method with a high predictive value for testing the susceptibilities of dermatophytes is necessary. OBJECTIVE: To evaluate the ability of the Sensititre YeastOne® in testing the activity of nine antifungal agents against dermatophytes. METHODS: We compared Sensititre® with reference procedure for anidulafungin (ANID), micafungin sodium (MCF), caspofungin acetate (CAS), 5-fluorocytosine (5FC), posaconazole (PCZ), voriconazole (VCZ), itraconazole (ITZ), fluconazole (FLZ) and amphotericin B (AMB) against 79 dermatophyte isolates, the essential agreement (EA) and categorical agreement (CA) between the two methods were obtained. RESULTS: The MICs or MECs obtained by the Sensititre® were usually lower than those obtained by the M38-A2. The overall EA between the two methods of nine antifungals was best for 5FC (100%), followed by MCF (94.9%), PCZ (84.8%), AMB (67.1%), FLZ (65.8%), VCZ (63.3%), ANID (29.1%), ITZ (20.3%) and CAS (2.5%). The overall CA between the two methods for all drugs was 100% except for ANID (97.4%), MCF (95%) and PCZ (92.5%). Substantial discrepancies were observed with all drugs except for VCZ and 5FC. The results of M38-A2 in terms of GMIC (or GMEC) and MIC90 (or MEC90) were, in increasing order, as follows: MCF, PCZ, VCZ, ANID, ITZ, CAS, AMB, FLZ and 5FC. CONCLUSIONS: The Sensititre YeastOne® shows poor EA with the reference method for dermatophytes; therefore, M38-A2 should remain the reference procedure for antifungal susceptibility testing against dermatophytes.

Susceptibility testing of clinical isolates of Sporothrix globosa in Shandong, China.

OBJECTIVE: To evaluate the antifungal susceptibility of Sporothrix globosa isolated from Shandong, China, and compare the differences of antifungal activity in vitro between yeast and mycelial phases. METHODS: The in vitro sensitivity of mycelium phase and yeast phase of Sporothrix globosa to anidulafungin, micafungin, caspofungin, 5-flucytosine, posaconazole, voriconazole, itraconazole, fluconazole and amphotericin B was tested by Sensititre™ YeastOne™. The minimum inhibitory concentration (MIC) values of mycelium phase and yeast phase were calculated. SPSS 19.0 software was used to conduct non-parametric rank sum test for MIC values, and P < .05 was considered statistically significant. RESULTS: The mycelium phase and yeast phase were the most sensitive to itraconazole and the least sensitive to fluconazole. The yeast phase of the same strain was more sensitive to itraconazole, voriconazole, posaconazole, micafungin, anidulafungin, caspofungin and 5-fluorouracil, compared with the mycelium (P < .05). However, fluconazole and amphotericin B had no significant difference in mycelium phase and yeast phase. CONCLUSIONS: Itraconazole is the most active antifungal agent in vitro against S globosa. The yeast phase of the same strain is more sensitive than that of the mycelium.