Blocking CD40 Alleviates Th1 and Th17 Cell Responses in Elastin Peptide-Induced Murine Emphysema.

Purpose: To investigate the role of the CD40-CD40 ligand (CD40L) pathway in the regulation of Th1, Th17, and regulatory T (Treg)-cell responses in an elastin peptide (EP)-induced autoimmune emphysema mouse model. Methods: BALB/c mice were transnasally treated with EP on day 0, injected intravenously with anti-CD40 antibody via the tail vein on day 33, and sacrificed on day 40. The severity of emphysema was evaluated by determining the mean linear intercept (MLI) and destructive index (DI) from lung sections. The proportions of myeloid dendritic cells (mDCs) and Th1, Th17, and Treg cells in the blood, spleen, and lungs were determined via flow cytometry. The levels of the cytokines interleukin (IL)-6, IL-17, interferon (IFN)-γ, and transforming growth factor (TGF)-ß were detected via enzyme-linked immunosorbent assay. Ifnγ, IL17a, Rorγt and Foxp3 transcription levels were detected via polymerase chain reaction. Results: CD40+ mDCs accumulated in the lungs of EP-stimulated mice. Blocking the CD40-CD40L pathway with an anti-CD40 antibody alleviated Th1 and Th17 responses; increased the proportion of Treg cells; decreased MLI and DI; reduced the levels of cytokines IL-6, IL-17, and IFN-γ as well as the transcription levels of Ifnγ, IL17a, and Rorγt; and upregulated the expression of TGF-ß and Foxp3. Conclusion: The CD40-CD40L pathway could play a critical role in Th1, Th17 and Treg cell dysregulation in EP-mediated emphysema and could be a potential therapeutic target.

RNA Sequencing and Related Differential Gene Expression Analysis in a Mouse Model of Emphysema Induced by Tobacco Smoke Combined with Elastin Peptides.

Objective: To establish a model of emphysema induced by tobacco smoke combined with elastin peptides (EP), explore the biochemical metabolic processes and signal transduction pathways related to emphysema occurrence and development at the transcriptional level, and identify new targets and signaling pathways for emphysema prevention and treatment. Methods: Mice were randomly divided into the air pseudoexposure group (NORMAL group) and the tobacco smoke + EP group (EP group). The differentially expressed genes (DEGs) in lung tissue between the two groups were identified by RNA-seq, and functional annotation and Gene Ontology (GO)/ Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The differential expression of the selected genes were verified using qRT‒PCR and immunohistochemistry (IHC). Results: EP group mice showed emphysema-like changes. The expression levels of 1159 genes in the EP group differed significantly (529 up-regulated and 630 down-regulated) from those in the NORMAL group. GO enrichment analysis showed that the DEGs were significantly enriched in the terms immune system, adaptive immune response, and phosphorylation, while KEGG pathway enrichment analysis showed that the DEGs were enriched mainly in the pathways cytokine‒cytokine receptor interaction, T-cell receptor signaling pathway, MAPK signaling pathway, Rap1 signaling pathway, endocytosis, chemokine signaling pathway, Th17 cell differentiation, and Th1 and Th2 cell differentiation. The differential expression of the selected DEGs were verified by qRT‒PCR and IHC, and the expression trends of these genes were consistent with those identified by RNA-seq. Conclusion: Emphysema may be related to the inflammatory response, immune response, immune regulation, oxidative stress injury, and other biological processes. The Bmp4-Smad-Hoxa5/Acvr2a signaling pathway may be involved in COPD/ emphysema occurrence and development.

Intravenous Cyclophosphamide Therapy for Anti-IFN-γ Autoantibody-Associated Talaromyces marneffei Infection.

High titers of anti-interferon-γ autoantibodies (AIGAs) are an important factor leading to persistent, relapsed, and refractory infections in HIV-negative hosts infected with Talaromyces marneffei (TM). We report 5 patients treated with pulses of high-dose intravenous cyclophosphamide (IVCY) who were followed for 2 years. Before IVCY therapy, all patients had multiple relapses, with a median (interquartile range [IQR]) of 2 (1-3) instances of relapse. The median serum AIGA titers (IQR) were 58 753 (41 203-89 605) ng/mL at diagnosis, 48 189.4 (15 537-83 375) ng/mL before IVCY therapy, and 10 721.2 (5637-13 245) ng/mL at the end of IVCY therapy (P < .05). After 3 months of follow-up, the median AIGA titers (IQR) rose gradually to 21 232.6 (9896-45 626) ng/mL, and to 37 464.2 (19 872-58 321) ng/mL at 24 months (P < .05). Five patients discontinued antimicrobial therapy within 3-12 months after completion of IVCY therapy, but only 1 patient had a relapse. In conclusion, pulses of short-term and high-dose IVCY can effectively reduce AIGA titers.

Talaromyces marneffei and Burkholderia cepacia Co-Infection in a HIV-Uninfected Patient with Anti-Interferon-γ Autoantibodies.

A high titer of neutralizing anti-interferon-γ autoantibodies can cause immunodeficiency associated with severe or disseminated infections caused by Talaromyces marneffei in human immunodeficiency virus-negative patients. Herein, we reported a rare case of disseminated Talaromyces marneffei and Burkholderia cepacia infection. The patient's lungs, lymph nodes, and bronchi were involved, and he had neck abscesses and osteomyelitis. We measured the neutralizing anti-interferon-γ autoantibodies in the peripheral blood and found that the patient had a persistently high positive titer. Despite aggressive treatment, the patient developed disseminated intravascular coagulation and died. Thus, high-titer nAIGAs may be associated with multiple opportunistic, persistent and disseminated infections.

Disseminated Talaromyces marneffei infection presenting as multiple intestinal perforations and diffuse hepatic granulomatous inflammation in an infant with STAT3 mutation: a case report.

BACKGROUND: Talaromyces marneffei is a highly pathogenic fungus that can cause life-threatening fatal systemic mycosis. Disseminated Talaromycosis marneffei affects multiple organs, including the lungs, skin, and reticuloendothelial system. However, T. marneffei infection has rarely been reported in human immunodeficiency virus (HIV)-negative infants with multiple intestinal perforations and diffuse hepatic granulomatous inflammation. CASE PRESENTATION: We present the case of an HIV-negative 37-month-old boy who has had recurrent pneumonia since infancy and was infected with disseminated Talaromycosis. Contrast-enhanced computed tomography of the whole abdomen showed hepatomegaly and intestinal wall thickening in the ascending colon and cecum with mesenteric lymphadenopathy. Colonoscopy showed a cobblestone pattern with erosion, ulcer, polypoid lesions, and lumen deformation ranging from the colon to the cecum. T. marneffei was isolated from the mucous membrane of the colon, liver, and bone marrow. After antifungal treatment and surgery, his clinical symptoms significantly improved. Whole-exome sequencing using the peripheral blood of the patient and his parents' revealed a heterozygous missense mutation in exon 17 of the STAT3 gene (c.1673G>A, p.G558D). CONCLUSIONS: In T. marneffei infection-endemic areas, endoscopic examination, culture, or histopathology from the intestine tissue should be performed in disseminated Talaromycosis patients with gastrointestinal symptoms. Timely and systemic antifungal therapy could improve the prognosis. Immunodeficiency typically should be considered in HIV-negative infants with opportunistic infections.

Assessment of Talaromyces Marneffei Infection of the Intestine in Three Patients and a Systematic Review of Case Reports.

BACKGROUND: Hematogenous dissemination of Talaromyces marneffei can result in multiorgan involvement (skin, lung, and reticuloendothelial system involvement); however, few studies have reported intestinal T marneffei infections. We investigated clinical features, management, and patient outcomes concerning Talaromyces-related intestinal infections. METHODS: Patients with Talaromycosis between August 2012 and April 2019 at The First Affiliated Hospital of Guangxi Medical University, China, were retrospectively analyzed. Patients presenting with intestinal Talaromycosis and endoscopy-confirmed diagnoses were investigated. We also undertook a systematic review of the relevant English and Chinese literature. RESULTS: Of 175 patients diagnosed with Talaromycosis, 33 presented with gastrointestinal symptoms, and 31 underwent stool cultures, 1 of which tested positive. Three patients had gastrointestinal symptoms and negative stool cultures, and endoscopic tissue biopsy confirmed a pathological diagnosis. A systematic review of 14 reports on human Talaromycosis identified an additional 16 patients. Fever, weight loss, and anemia were the most common symptoms, along with abdominal pain, diarrhea, and bloody stools. Abdominal computed tomography showed intestinal wall edema and thickening and/or abdominal lymphadenopathy. Endoscopy showed erosion, hyperemia, edema, and multiple intestinal mucosal ulcers. Of the 19 patients, 16 received antifungal therapy, 14 of whom recovered and 2 died. Three patients received no therapy and died. CONCLUSIONS: Gastrointestinal disseminated Talaromycosis is not rare and can affect the stomach, duodenum, and colon, and may involve the entire digestive tract. Colon is the most common site. Endoscopy is needed for patients presenting with gastrointestinal symptoms in T marneffei-infected endemic areas. Systemic application of effective antifungal therapy can improve the prognosis.

Dendritic Cells Promote Treg Expansion but Not Th17 Generation in Response to Talaromyces marneffei Yeast Cells.

BACKGROUND: Dendritic cells (DCs) with both proinflammatory and tolerogenic properties have been implicated in modulation of CD4+ T cell responses in many fungal diseases. However, the role of DC in the context of Talaromyces marneffei (T. marneffei) infection has not been determined. In this study, we aimed to study the effect of the yeast form of T. marneffei yeasts on DCs, as well as the role of DCs in modulating T helper 17 (Th17) and regulatory T (Treg) cell responses to the pathogen. METHODS: Mouse bone marrow-derived DCs were stimulated with T. marneffei yeasts for 24 h. Frequencies of CD80 and CD86 expression on DCs and the levels of IL-6, IL-10 and TGF-ß in the culture supernatant of yeast-stimulated DCs were detected by flow cytometry and ELISA, respectively. In co-culture experiments, CD4+ T lymphocytes of mice were isolated from the spleen using magnetic beads and co-cultured with T. marneffei yeasts, with or without DCs for 24 h. The proportions of Th17 and Treg cells in co-culture were detected by flow cytometry. The mRNA levels of RORγt and Foxp3 were detected by RT-PCR. Levels of IL-10 and TGF-ß in the co-culture supernatant were detected by ELISA. RESULTS: The expressions of CD80 and CD86 on DCs were increased, as well as IL-6, IL-10 and TGF-ß levels in the culture supernatant of T. marneffei-stimulated DCs were higher than those in DCs cultured without T. marneffei. In co-culture experiments, in the presence of DCs, T. marneffei promoted Treg expansion and Foxp3 up-regulation but limited Th17 and downregulated RORγt. Levels of IL-10 and TGF-ß were higher in the co-culture containing DCs than without DCs. CONCLUSION: Our findings demonstrated that the interaction between DCs and T. marneffei could promote Treg expansion but not Th17 generation. These findings provide a mechanism by which DCs may promote immune tolerance in T. marneffei infection.

Talaromycosis-Associated Secondary Hemophagocytic Lymphohistiocytosis in Nine Human Immunodeficiency Virus-Negative Patients: A Multicenter Retrospective Study.

PURPOSE: Talaromyces marneffei (T.M) is an intracellular opportunistic fungus that causes invasive mycosis in patients with or without human immunodeficiency virus (HIV) infection. Hemophagocytic lymphohistiocytosis (HLH) caused by T.M infection is extremely rare. Here, we analyzed the clinical features, immune mechanisms, treatment, and prognosis related to this comorbidity. PATIENTS AND METHODS: This retrospective study was conducted between August 2012 and February 2019 at multiple research centers. Patients who presented with culture and/or histopathological proof of talaromycosis-associated HLH were included. RESULTS: HIV-negative patients (n = 126) were enrolled. Of nine patients with T.M infection combined with secondary HLH, six were preschool children (five boys and one girl), and three were adults (two men and one woman). Seven of these nine had underlying diseases or recurrent infections. The most common symptoms were fever, anemia, hypoproteinemia, cough, weight loss, oral thrush, lymphadenopathy, hepatomegaly, splenomegaly, digestive symptoms, joint pain, and dyspnea. All patients showed reduced hemoglobin concentrations and platelet numbers. Liver dysfunction, hyperferritinemia, elevated lactate dehydrogenase, and low natural killer cell numbers were observed. Eight of nine patients received antifungal therapy, one patient did not receive therapy, and two of nine patients received anti-HLH therapy. Four died during treatment. CONCLUSION: T.M fungemia associated with HLH was related to high mortality. Once diagnosed, timely and effective antifungal treatments and supportive care are essential.

Erythromycin Prevents Elastin Peptide-Induced Emphysema and Modulates CD4+T Cell Responses in Mice.

Purpose: Elastin peptides (EP) can induce lung inflammation and emphysema. Erythromycin has been shown to decrease acute exacerbation frequency and delay lung function decline in chronic obstructive pulmonary disease patients and ameliorate emphysema in murine models; however, the mechanism remains unclear. We aimed to observe the preventive and immunomodulatory effects of erythromycin in a mouse model of EP-induced emphysema. Methods: In the in vivo study, Balb/c mice were treated with EP intranasally on day 0, and then administered erythromycin (100 mg/kg) or vehicle orally on day 1, which was continued every other day. Mice exposed to cigarette smoke were used as an emphysema positive control. The severity of emphysema and inflammation in the lungs of EP-exposed mice with or without erythromycin treatment were observed on day 40 after EP administration. In the in vitro study, naïve CD4+T cells were isolated from healthy mice spleens and stimulated by EP with or without erythromycin incubation. Flow cytometry was used to measure the proportions of Th1, Th17, and Treg cells. ELISA was used to detect cytokine levels of IFN-γ, IL-17, IL-6, and TGF-ß. Transcript levels of Ifnγ, IL17a, and Foxp3 were evaluated by qRT-PCR. Results: After exposure to EP, Th1 and Th17 cell percentages and the levels of inflammatory cytokines increased in vivo and in vitro, while Treg cells decreased in vivo. Erythromycin reduced IFN-γ, IL-17, IL-6 inflammatory cytokines, MLI, and the inflammation score in the lungs of EP-exposed mice. In vitro, erythromycin also limited Th17 and Th1 cell differentiation and downregulated transcript levels of Ifnγ and IL17a in the EP-stimulated CD4+T cells. Conclusion: The Th1 and Th17 cell responses were increased in EP-induced emphysema. Prophylactic use of erythromycin effectively ameliorated emphysema and modulated CD4+T cells responses in EP-induced lung inflammation in mice.

Characterization of Anti-Interferon-γ Antibodies in HIV-Negative Patients Infected With Disseminated Talaromyces marneffei and Cryptococcosis.

BACKGROUND: Few reports of Talaromyces marneffei (TM) or cryptococcosis infections among HIV-negative patients with high-titeranti-IFN-γautoantibodies (nAIGAs) have been published. We investigated the clinical manifestations of patients with nAIGAs and TM infections. METHODS: HIV-negative adults (≥18 years) were enrolled if they haddisseminated TM infection (group 1; further divided into nAIGAs positive [group 1P] and negative [group 1N]); cryptococcosis(pulmonary cryptococcosis and/or cryptococcosis of the brain)(group 2); pulmonary tuberculosis (group 3); and healthy controls (group 4) with nAIGAs detected. Complete histories, physical examinations, and routine clinical laboratory tests were obtained at baseline. RESULTS: Overall, 88 participants were in the four groups (20,13,23, and 32 in groups 1 to 4, respectively). Significant differences occurred between groups with higher nAIGAs titers (P < 0.001), and higher total white-cell and absolute neutrophil counts (P < 0.001) in group1. Lungs (90.0%), lymph nodes (60.0%), skin (55.0%), and bones (50.0%) were most common sites of involvement. Significant differences in total white-cell and absolute neutrophil counts occurred between groups IP and 1N.Patients with recurrent TM infections, particularly group 1P, had higher initial nAIGA titer. CONCLUSIONS: Patients with persistent infection who died tended to have positive initial nAIGA titer. It suggests that nAIGAs may play a critical role in the pathogenesis of TM infections, and may be associated with more severe, refractory infection.

Comparison of pleural effusion features and biomarkers between talaromycosis and tuberculosis in non-human immunodeficiency virus-infected patients.

BACKGROUND: Due to the similar clinical, lung imaging, and pathological characteristics, talaromycosis is most commonly misdiagnosed as tuberculosis. This study aimed to identify the characteristics of talaromycosis pleural effusion (TMPE) and to distinguish TMPE from tuberculosis pleural effusion (TPE). METHODS: We enrolled 19 cases each of TMPE and TPE from Guangxi, China. Patients' clinical records, pleural effusion tests, biomarker test results, and receiver operating characteristic curves were analyzed. RESULTS: In total, 39.8% (65/163) of patients exhibited serous effusion, of whom 61 were non-human immunodeficiency virus (HIV)-infected patients; 68.85% of the non-HIV-infected patients (42/61) had TMPE. Thoracentesis was performed only in 19 patients, all of whom were misdiagnosed with tuberculosis and received long-term anti-tuberculosis treatment. In four of these patients, interleukin (IL)-23, IL-27, and interferon-gamma (IFN-γ) measurements were not performed since pleural effusion samples could not be collected because the effusion had been drained prior to the study. In the remaining 15 patients, pleural effusion samples were collected. Talaromyces marneffei was isolated from the pleural effusion and pleural nodules. Most TMPEs were characterized by yellowish fluid, with marked elevation of protein content and nucleated cell counts. However, neutrophils were predominantly found in TMPEs, and lymphocytes were predominantly found in TPEs (both p < 0.05). Adenosine deaminase (ADA) and IFN-γ levels in TMPEs were significantly lower than those in TPEs (all p < 0.05) and provided similar accuracies for distinguishing TMPEs from TPEs. IL-23 concentration in TMPEs was significantly higher than that in TPEs (p < 0.05), and it provided similar accuracy for diagnosing TMPEs. IL-27 concentrations in TMPEs were significantly lower than those in TPEs (all p < 0.05) but was not useful for distinguishing TMPE from TPE. CONCLUSIONS: Talaromycosis can infringe on the pleural cavity via the translocation of T. marneffei into the pleural space. Nonetheless, this phenomenon is still commonly neglected by clinicians. TMPE is a yellowish fluid with exudative PEs and predominant neutrophils. Higher neutrophil counts and IL-23 may suggest talaromycosis. Higher lymphocyte counts, ADA activity, and IFN-γ concentration may suggest tuberculosis.

Determinants of prognosis in Talaromyces marneffei infections with respiratory system lesions.

BACKGROUND: Little study has investigated the differences between Talatomyces marneffei (T. marneffei) respiratory infection and tuberculosis and the prognostic factors of such infection. This study investigated the characteristics and prognostic factors of T. marneffei infections with respiratory lesions and the causes of misdiagnosis. METHODS: Clinical characteristics and prognoses of patients with T. marneffei infections with respiratory system lesion were investigated. T. marneffei diagnosis followed isolation from clinical specimens using standard culture, cytology, and histopathology. Survival curves were estimated by using Kaplan-Meier analysis, with log-rank test to compare differences in survival rates between groups. Univariate and multivariate Cox regression analyses were also performed to assess significant differences in clinical characteristics of overall survival. RESULTS: Of 126 patients diagnosed with T. marneffei infections, 63 (50.0%) had T. marneffei respiratory system infections; 38.1% (24/63) were misdiagnosed as having tuberculosis. Human immunodeficiency virus (HIV) infection, CD4/CD8 < 0.5, percentage of CD4 T cells <42.8%, and length of time from onset to confirmation of diagnosis >105 days were potential risk factors for poor prognoses. Length of time from onset to confirmation of diagnosis persisted as an independent predictor of all-cause mortality in multivariate analysis (odds ratio: 0.083, 95.0% confidence interval: 0.021-0.326, P < 0.001). However, the size of the lung lesions, dyspnea, thoracalgia, mediastinal lymphadenopathy, and pleural effusion did not significantly predict overall survival. There was no significant difference in prognosis according to the type of treatment. CONCLUSIONS: T. marneffei infections involving the respiratory system are common. The critical determinants of prognosis are HIV infection, CD4/CD8, percentage of CD4 T cells, type of treatment, and the time range from onset to confirmation of diagnosis. Rapid and accurate diagnosis is crucial for improving prognosis.