Th1 cell immune response in Talaromyces marneffei infection with anti-interferon-γ autoantibody syndrome.

Anti-interferon-γ autoantibody (AIGA) syndrome may be the basis of disseminated Talaromyces marneffei infection in human immunodeficiency virus (HIV)-negative adults. However, the pathogenesis of Th1 cell immunity in T. marneffei infection with AIGA syndrome is unknown. A multicenter study of HIV-negative individuals with T. marneffei infection was conducted between September 2018 and September 2020 in Guangdong and Guangxi, China. Patients were divided into AIGA-positive (AP) and AIGA-negative (AN) groups according to the AIGA titer and neutralizing activity. The relationship between AIGA syndrome and Th1 immune deficiency was investigated by using AP patient serum and purification of AIGA. Fifty-five HIV-negative adults with disseminated T. marneffei infection who were otherwise healthy were included. The prevalence of AIGA positivity was 83.6%. Based on their AIGA status, 46 and 9 patients were assigned to the AP and AN groups, respectively. The levels of Th1 cells, IFN-γ, and T-bet were higher in T. marneffei-infected patients than in healthy controls. However, the levels of CD4+ T-cell STAT-1 phosphorylation (pSTAT1) and Th1 cells were lower in the AP group than in the AN group. Both the serum of patients with AIGA syndrome and the AIGA purified from the serum of patients with AIGA syndrome could reduce CD4+ T-cell pSTAT1, Th1 cell differentiation and T-bet mRNA, and protein expression. The Th1 cell immune response plays a pivotal role in defense against T. marneffei infection in HIV-negative patients. Inhibition of the Th1 cell immune response may be an important pathological effect of AIGA syndrome.IMPORTANCEThe pathogenesis of Th1 cell immunity in Talaromyces marneffei infection with anti-interferon-γ autoantibody (AIGA) syndrome is unknown. This is an interesting study addressing an important knowledge gap regarding the pathogenesis of T. marneffei in non-HIV positive patients; in particular patients with AIGA. The finding of the Th1 cell immune response plays a pivotal role in defense against T. marneffei infection in HIV-negative patients, and inhibition of the Th1 cell immune response may be an important pathological effect of AIGA syndrome, which presented in this research could help bridge the current knowledge gap.

Serum sphingolipids aid in diagnosing adult HIV-negative patients with pulmonary cryptococcosis: a clinical cohort study.

Background: Pulmonary cryptococcosis (PC) contributes to the ongoing global disease burden in human immunodeficiency virus (HIV)-negative populations. Since some PC patients are misdiagnosed under existing diagnostic guidelines, new diagnostic markers are needed to improve diagnostic accuracy and therapeutic efficacy and reduce disease risk. Methods: Our previously established sphingolipidomic approach was employed to explore the use of serum sphingolipids (SPLs) in diagnosing HIV-negative patients with PC. A clinical cohort of PC, pulmonary aspergillosis (PA), and tuberculosis (TB) patients and healthy controls was assessed to identify SPL biomarkers. Results: A total of 47 PC, 27 PA, and 18 TB patients and 40 controls were enrolled. PC and TB patients had similar clinical features, laboratory test results and radiological features, excluding plural effusion. The serum ceramide [Cer (d18:1/18:0)] level showed a significant increase in PC patients compared to controls and PA and TB patients (P<0.05). Cer (d18:1/18:0) was identified as a specific diagnostic biomarker for PC. The optimal cut-off value of greater than 18.00 nM showed a diagnostic sensitivity of 76.60% and a specificity of 95.00% and better distinguished PC patients from PA and TB patients. Furthermore, the serum Cer (d18:1/18:0) level gradually decreased after 3 and 6 months of treatment, suggesting the prediction potential for therapeutic efficacy of this biomarker. In addition, Cer (d18:1/18:0) analysis presented a higher sensitivity than the cryptococcal antigen (CrAg) assay. Conclusions: This is the first study to report the use of the SPL Cer (d18:1/18:0) as a serum biomarker for diagnosing Cryptococcus spp. infection in HIV-negative patients.

Disseminated Talaromyces marneffei Infection With STAT3-Hyper-IgE Syndrome: A Case Series and Literature Review.

Background: Little is known about the clinical characteristics of talaromycosis with hyper-immunoglobulin E syndrome (HIES). Methods: We conducted a multicenter retrospective study, which included 7 hospitals from 2016 to 2022. Five consecutive cases of human immunodeficiency virus (HIV)-negative patients with systemic Talaromyces marneffei infections due to STAT3-HIES were identified. A systematic literature review of original articles published in English identified an additional 7 cases. Clinical characteristics and laboratory parameters were collected. Results: Forty-two percent (5/12) of patients were young adults. The main symptoms of 10 patients were similar: fever (75%), cough (75%) and dyspnea (33%), but two patients mainly had gastrointestinal symptoms. Most patients had a history of infections since infancy. T marneffei was cultured from the bronchoalveolar lavage fluid (50%) and 25% of patients were next-generation sequencing positive. Eight patients had significantly elevated serum immunoglobulin E, increased B cells and decreased natural killer cells. There were ten different STAT3 mutations, three of which were reported for the first time in this study. Chest computed tomography examinations showed multiple exudations with cavities in the lungs. Voriconazole combined with thymosin was effective. Despite given antifungal agents, most had poor outcomes and the case fatality rate was as high as 25%. Conclusions: STAT3-HIES is most likely a susceptibility factor for T marneffei infections among HIV-negative patients, which has a high case fatality rate. Increased awareness among clinicians is necessary to help in early diagnosis.

Allicin shows antifungal efficacy against Cryptococcus neoformans by blocking the fungal cell membrane.

Allicin, which is generated by the catalytic reaction between alliin and alliinase extracted from garlic, has been shown to have a wide range of antimicrobial activities, but its anti-Cryptococcus efficacy and mechanism are not quite clear. Here, we have determined that the Conversion rate of allicin in the reaction product reached 97.5%. The minimal inhibitory concentration (MIC) of allicin against Cryptococcus neoformans (C. neoformans) H99 was 2 µg/ml, which is comparable to fluconazole (FLU, 1 µg/ml). Furthermore, allicin exhibited effective antifungal activity against 46 clinical isolates of C. neoformans, and the MICs ranged from 1 to 8 µg/ml, even for AmB-insensitive strains. Interestingly, allicin also exerted additive or synergistic effects when combined with amphotericin B (AmB) and FLU. Time-killing curves and long-term live cell imaging of H99 showed that 4 MIC of allicin had fungicide activity. Additionally, allicin (4 and 8 mg/kg) exerted a dose-dependent therapeutic effect on H99-infected mice by significantly reducing the wet pulmonary coefficient and Cryptococcus load and reducing lung damage. Even the efficacy of 8 mg/kg was comparable to FLU (20 mg/kg). Transcriptomics revealed that allicin may act on the cell membrane of H99. Subsequently, transmission electron microscopy (TEM) observations showed that allicin clearly breached the cell membrane and organelles of H99. Confocal laser scanning microscopy (CLSM) results further confirmed that allicin disrupted the permeability of the cell membranes of H99 in a dose-dependent manner. Allicin exhibits strong anti-C. neoformans activity in vitro and in vivo, mainly by destroying the permeability and related functions of Cryptococcus cell membranes.

Pathogen spectrum and immunotherapy in patients with anti-IFN-γ autoantibodies: A multicenter retrospective study and systematic review.

Background: Anti-interferon-γ autoantibody (AIGA) positivity is an emerging immunodeficiency syndrome closely associated with intracellular infection in individuals without human immunodeficiency virus (HIV). However, the information on epidemiology, pathogen spectrum, and immunotherapy among these patients lack a systematic description of large data. Methods: This systematic literature review and multicenter retrospective study aimed to describe the pathogen spectrum and review treatment strategies among patients with AIGA positivity. Results: We included 810 HIV-negative patients with AIGA positivity infected with one or more intracellular pathogens. Excluding four teenagers, all the patients were adults. The most common pathogen was nontuberculous mycobacteria (NTM) (676/810, 83.5%). A total of 765 NTM isolates were identified in 676 patients with NTM, including 342 (44.7%) rapid-grower mycobacteria, 273 (35.7%) slow-grower mycobacteria, and 150 (19.6%) unidentified NTM subtype. Even with long-term and intensive antimicrobial treatments, 42.6% of patients with AIGA positivity had recurrence and/or persistent infection. Sixty-seven patients underwent immunoregulatory or immunosuppressive therapy, and most (60) achieved remission. The most common treatment strategy was rituximab (27/67, 40.3%) and cyclophosphamide (22/67, 32.8%), followed by cyclophosphamide combined with glucocorticoids (8/67, 11.9%). Conclusions: Intracellular pathogen was the most common infection in patients with AIGA positivity. The predominant infection phenotypes were NTM, varicella-zoster virus, Talaromyces marneffei, and Salmonella spp., with or without other opportunistic infections. AIGA immunotherapy, including rituximab or cyclophosphamide, has yielded good preliminary results in some cases.

Development and clinical application of an electronic health record quality control system for pulmonary aspergillosis based on guidelines and natural language processing technology.

Background: There are considerable differences in the diagnosis and treatment of pulmonary aspergillosis (PA) between specialized hospitals and primary hospitals or developed areas and underdeveloped areas in China. There is a lack of electronic systems that assist respiratory physicians in standardizing the diagnosis and treatment of PA. Methods: We extracted 26 quality control points from the latest guidelines related to PA, and developed a PA quality control system of electronic health record (EHR) based on natural language processing (NLP) techniques. We obtained PA patient records in the Department of Respiratory Medicine of the First Affiliated Hospital of Guangzhou Medical University to verify the effectiveness of the system comparing with manually evaluation of respiratory experts. Results: We successfully developed quality control system of PA; 699 PA medical records from EHR of the First Affiliated Hospital of Guangzhou Medical University between January 2015 and March 2020 were obtained and assessed by the system; 162 defects were found, which included 19 medical records with diagnostic defects, 76 medical records with examination defects, and 80 medical records with treatment defects; 200 medical records were sampled for validation, and found that the sensitivity and accuracy of quality control system for pulmonary aspergillosis (QCSA) were 0.99 and 0.96, F1 value was 0.85, and the recall rate was 0.77 compared with experts' evaluation. Conclusions: Our system successfully uses medical guidelines and NLP technology to detect defects in the diagnosis and treatment of PA, which helps to improve the management quality of PA patients.

Lithocholic acid inhibits dendritic cell activation by reducing intracellular glutathione via TGR5 signaling.

Dendritic cells (DCs) are the major antigen-presenting cells and play an important role in autoimmune uveitis. Emerging evidence suggests that bile acids (BAs) regulate DCs maturation. However, the underlying mechanisms by which BAs regulate the function of DCs still need to be clarified. Here, we demonstrate that lithocholic acid (LCA) inhibits the production of pro-inflammatory cytokines and the expression of surface molecules in bone marrow-derived dendritic cells (BMDCs). LCA attenuates the severity of EAU by modulating the maturation of splenic CD11C+MHCIIhigh DCs. Notably, Takeda G-protein coupled receptor 5 (TGR5) deficiency partially reverses the inhibitory effect of LCA on DCs in vitro and in vivo. TGR5 activation also downregulates the NF-κB and MAPK pathways by inhibiting glutathione production and inducing oxidative stress in DCs, which leads to apoptosis and autophagy in DCs. In addition, LCA or INT-777 treatment increases the TGR5 expression in monocyte-derived dendritic cells (MD-DCs) of patients with active BD, whereas both LCA and TGR5 agonists inhibit the activation of MD-DCs. These results suggest that LCA and TGR5 agonists might be potential therapeutic drugs for the treatment of autoimmune uveitis.

HMGB1 downregulation in retinal pigment epithelial cells protects against diabetic retinopathy through the autophagy-lysosome pathway.

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus and currently one of the major causes of blindness. Several previous studies have demonstrated that autophagy, which is regulated by HMGB1 (high mobility group box 1), is involved in DR development. However, the role of autophagy in DR is quite complicated in that it promotes pericyte survival in early DR, whereas excessive autophagy causes excess stress and leads to necrosis. Therefore, this study aimed to investigate the relationship between HMGB1, the macroautophagy/autophagy-lysosome pathway, and DR, as well as their underlying molecular mechanisms. In brief, the relationship between high glucose (HG) and the autophagy-lysosome pathway was examined in retinal pigment epithelial (RPE) cells. The relationship was studied by detecting classical autophagic features, and siRNAs targeting HMGB1 and pharmacological regulators were used to explore the role of the autophagy-lysosome pathway in DR development. The results demonstrated that HG inhibited autophagy and diminished the degradative capacity of autophagy due to lysosome membrane permeabilization (LMP). In addition, HMGB1 was found to be involved in LMP via the CTSB (cathepsin B)-dependent pathway, but not the CTSL (cathepsin L)-dependent pathway. Knockdown of HMGB1 expression rescued LMP, restored the degradative capacity of autophagy, decreased the expression of inflammatory factors and VEGF (vascular endothelial growth factor), and protected against apoptosis in RPE cells in the early stages of DR.

A20 Inhibits Intraocular Inflammation in Mice by Regulating the Function of CD4+T Cells and RPE Cells.

A20 is a negative regulator of inflammation and immunity and plays a role in several autoimmune and inflammatory diseases. Here, we demonstrate that A20 overexpression significantly ameliorates severity of EAU by inhibiting the infiltration of Th1 and Th17 cells, and by protecting integrity of the blood retinal barrier. In vitro studies showed that A20 silencing could promote CD4+T cells toward a Th1 and Th17 phenotype. A decreased expression of A20 in CD4+T cells was noticed in active BD patients but not in VKH patients. Furthermore, silencing of A20 in hRPE cells induced the production of IL-6, IL-8, and MCP-1 and downregulated ZO-1 and occludin expression which is mediated by inhibition of MAPK and NF-κB pathways. This study reveals a mechanism by which A20 prevents autoimmune uveitis.

Decreased Expression of TGR5 in Vogt-Koyanagi-Harada (VKH) Disease.

Purpose: To investigate the role of G-protein-coupled bile acid receptor-1, Gpbar1 (TGR5) in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease.Methods: The mRNA level of TGR5, iNOS, Arg1, CD16, and CD206 in macrophages was assayed by real-time PCR. ELISA was used to detect the production of cytokines in cell culture supernatants. The frequencies of CD4+IFN-γ+ and CD4+ IL-17+ T cells were tested by flow cytometry.Results: A decreased expression of TGR5 in M1 macrophages was observed in active VKH patients as compared with normal controls. TGR5 stimulation of M1 macrophages with INT-777 caused a shift of the inflammatory M1 toward the anti-inflammatory M2 macrophage subtype. TGR5 activation of macrophages co-cultured with CD4+ T cells inhibited Th1 and Th17 polarization, as well as the release of IFN-γ and IL-17 in the culture supernatant.Conclusion: Our results show that a decreased TGR5 expression might contribute to the pathogenesis of VKH disease.

Decreased interleukin(IL)-35 Expression is Associated with Active Intraocular Inflammation in Vogt-Koyanagi-Harada (VKH) Disease.

Purpose: Recent studies have reported that IL-35 has a protective effect in autoimmune disease. In this study, we explored the role of IL-35 in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease. Methods: The IL-35/EBI3 and IL-35/P35 mRNA level was assayed by Real-Time PCR. The level of IL-35 in serum was detected by ELISA. PBMCs and monocyte-derived DCs were cultured with or without IL-35 and the concentration of IL-17, IL-10, IFN-γ, IL-6, TNF-α, and IL-1ß in supernatants was tested by ELISA. Results: The serum level of IL-35 is reduced in active VKH patients. The mRNA expression of the two subunits IL-35/EBI3 and IL-35/P35 in PBMCs from patients with active VKH was also decreased. IL-35 significantly inhibited IFN-γ and IL-17 expression and induced IL-10 production by PBMCs and inhibited IL-6 production by monocyte-derived DCs. Conclusion: The current study suggests that a decreased IL-35 expression may be involved in the pathogenesis of VKH disease.

Trimethylamine-N-oxide (TMAO) increased aquaporin-2 expression in spontaneously hypertensive rats.

Recent evidence suggests that elevated plasma levels of Trimethylamine-N-oxide (TMAO) can prolong the duration of elevated blood pressure in rats. The purpose of this study was to investigate the plasma TMAO level in Spontaneously Hypertensive Rats (SHR) and to explore the possible relationship between TMAO and aquaporin-2 (AQP-2) in the formation of hypertension. Twelve-week-old, male Spontaneously Hypertensive rats (SHR, n = 40) and Wistar-Kyoto rats (WKY, n = 40) were accordingly grouped into SHR group and WKY group. Each group was divided randomly into four subgroups: Untreated group, TMAO group, TMAO+Tolvaptan (TMAO+TVP) group, and TVP group, respectively. Systolic blood pressure (SBP), plasma TMAO, plasma osmolality (POsm), plasma vasopressin (PAVP), and plasma AQP-2 (PAQP-2) concentration were measured, and the expression of AQP-2 in kidney medulla was detected by RT-PCR and Western blot. At 14 weeks, rats in SHR TMAO group were shown the increased plasma TMAO, POsm, PAVP, and PAQP-2 levels, while those rats in SHR TMAO+TVP group were shown the decreased plasma TMAO, POsm, and PAQP-2 levels, but an even higher PAVP (due to the blockage of TVP to V2 receptor). These findings indicate that an increase of plasma TMAO levels in SHR leads to a higher plasma osmotic pressure, triggers the regulation of the TMAO-AVP-AQP-2 axis in SHR, elicits the greater water reabsorption, and eventually leads to hypertension.

[Involvement of heme oxygenase in PM2.5-toxicity in human umbilical vein endothelial cells].

OBJECTIVE: To investigate the involvement of heme oxygenase (HO-1) in PM2.5 induced toxic responses in human umbilical vein endothelial cells (HUVECs). METHODS: The experiment groups are as follows: (1) control group; (2) PM2.5 groups: the cells were cultured with various concentrations of PM2.5 (200, 400, 800 µg/ml) for 24 h and 400 µg/ml was chosen for the main study; (3) PM2.5+Trion group: the cells were pre-treated by 10 µmol/L Trion [a scavenger of reactive oxygen species(ROS)] for 1 h before PM2.5 (400 µg/ml) treatment for 24 h; (4) PM2.5+ZnPP group: the cells were pretreated by HO-1 inhibitor ZnPP (10 µmol/L) for 1 h before treatment with PM2.5 (400 µg/ml) for 24 h. MTT assay was used to detect cell viability. Reverse transcription polymerase chain reaction (RT-PCR) and indirect immunofluorescence assay were used to determine the mRNA and protein expressions of HO-1. Fluorescence labeling probe method was used to measure intracellular ROS level and flow cytometry was used for cell apoptosis. Colorimetric assay was used to detect intracellular caspase-3 activity. RESULTS: Compared with control, PM2.5 significantly decreased cell viability, increased intracellular ROS, cell apoptosis and caspase-3 activity (all P < 0.05), these effects were significantly attenuated in PM2.5+Tiron group while enhanced in PM2.5+ZnPP group (all P < 0.05 vs. PM2.5 group). PM2.5 upregulated HO-1 mRNA and protein expressions in HUVECs which was downregulated in both PM2.5+Tiron group and PM2.5+ZnPP group. CONCLUSION: PM2.5 could induce oxidative injury through increasing ROS production via modulating HO-1 mRNA and protein expressions, the injury could be aggravated with inhibition of the activity of HO-1 suggesting a potential protective role of HO-1 against PM2.5 induced oxidative stress in HUVECs.