Cyclophosphamide reduces dectin-1 expression in the lungs of naive andAspergillus fumigatus-infected mice

Fuzi polysaccharides improve immunity in immunosuppressed mouse models by regulating gut microbiota composition

Rationale and objectives

Fuzi, the dried root of Aconitum carmichaelii Debx, is one of the widely used traditional Chinese medicines. Fuzi polysaccharides are considered the most bioactive compounds with immunomodulatory functions, however, the mechanisms have not been evaluated. This study aims to systematically investigate the effects of Fuzi polysaccharides on the gut microbiota and immune function using a mouse model immunosuppressed with cyclophosphamide.

Methods

The short-chain fatty acid levels in cecal contents were measured by gas chromatography-mass spectrometry. The gut microbiota 16S rRNA gene were sequenced by next generation sequencing. The mRNA expression levels of NF-κB, IL-6, TNF-α, iNOS and COX-2 were measured using quantitative real-time polymerase chain reaction. The protein expression of occludin and zonula occludens-1 were analyzed by Western blot. The white blood cells were counted using automated hematology analyzer, and CD4⁺FOXP3⁺/CD4⁺ ratio was measured by flow cytometry.

Results and Conclusions

Fuzi polysaccharides had the function of elevating the concentration of acetic acid, propionic acid, isobutyric acid, and n-butyric acid in the cecum. Meanwhile, Fuzi polysaccharides could decrease the relative abundance of Helicobacter, Anaerotruncus, Faecalibacterium, Lachnospira, Erysipelotrichaceae_UCG-003, Mucispirillum, and Mycoplasma, and increase the relative abundance of Rhodospirillales, Ruminococcaceae_UCG-013, Mollicutes_RF39, Ruminococcus_1, Christensenellaceae_R-7_group, and Muribaculaceae in the gut. Furthermore, Fuzi polysaccharides exhibited the function of increasing spleen and thymus indices and number of white blood cells and lymphocytes. Fuzi polysaccharides could reverse the decreased mRNA expression of NF-кB, IL-6, and iNOS, differentiation of CD4⁺FOXP3⁺ regulatory T cells as well as protein expression of occludin and zonula occludens-1 induced by cyclophosphamide. In addition, the mRNA and protein expression of cytokines were significantly correlated with the abundance of gut microbiota under Fuzi polysaccharides treatment. Collectively, the above results demonstrated that Fuzi polysaccharides could regulate inflammatory cytokines and gut microbiota composition of immunosuppressive mice to improve immunity, thereby shedding light on revealing the molecular mechanism of polysaccharides of traditional Chinese medicines in the future.

Disseminated cerebral aspergillosis complicated by thrombotic microangiopathy

Invasive aspergillosis (IA) is a serious condition that can affect almost any organ. Cerebral aspergillosis itself is rapidly fatal without treatment. We report a case of disseminated cerebral IA in a patient exposed to cyclophosphamide, rituximab and prednisone. This case is unique because: 1) disseminated IA has not been described in anti-glomerular basement membrane glomerulonephritis; 2) IA led to thrombotic microangiopathy with normal ADAMTS13 and 3) voriconazole toxicity necessitated use of isavuconazole for IA treatment.

Invasive aspergillosis in patients with systemic lupus erythematosus: a retrospective study on clinical characteristics and risk factors for mortality

Objective

The objective of this paper is to analyze the clinical features, outcomes, mortality risk factors, and all-cause mortalities of invasive aspergillosis (IA) in patients with systemic lupus erythematosus (SLE).

Methods

Medical records were reviewed to identify SLE patients with IA from January 2006 to June 2017, at Taipei Veterans General Hospital, Taiwan. A total of 6714 SLE patients were included. Clinical/laboratory parameters and treatment outcomes were analyzed.

Results

Four patients (19.0%) had definite and 17 had probable (81.0%) IA. Seven patients (33.3%) survived and 14 died (66.7%). Concurrently, there were 19 pneumonias (90.5%), 17 cases of other infections (81.0%), eight bacteremia (38.1%), nine cytomegalovirus (CMV, 42.7%) and six Candida (28.6%) infections. In all 55 blood cultures, 38 (69.1%) yielded gram-negative bacilli, of which carbapenem-resistant A. baumannii accounted for eight (21.1%); 17 (30.9%) yielded gram-positive cocci, of which methicillin-resistant S. aureus accounted for six (35.3%); and vancomycin-resistant Enterococcus accounted for four (23.5%). Daily steroid dose ≥ 20 mg (hazard ratio (HR) 2.00), recent pulse steroid therapy (HR 2.80), azathioprine (HR 2.00), rituximab (HR 2.00), plasmapheresis (HR 2.00), acute respiratory distress syndrome (HR 2.00), concurrent infections (HR 5.667) and CMV viremia (HR 1.75) were higher in the fatality group. All p values were less than 0.05. Septic shock ( n = 7, 50% in the fatality group) is the most common cause of mortality.

Conclusions

High daily steroid dosing, recent pulse steroid therapy, azathioprine, rituximab, concurrent infections, and CMV viremia were mortality risk factors for IA in SLE.

Combination of Estrogen and Immunosuppressive Agents to Establish a Mouse Model of Candidiasis with Concurrent Oral and Vaginal Mucosal Infection

Mouse model is an appropriate tool for pathogenic determination and study of host defenses during the fungal infection. Here, we established a mouse model of candidiasis with concurrent oral and vaginal mucosal infection. Two C. albicans strains sourced from clinical candidemia (SC5314) and mucosal infection (ATCC62342) were tested in ICR mice. The different combinational panels covering estrogen and immunosuppressive agents, cortisone, prednisolone and cyclophosphamide were used for concurrent oral and vaginal candidiasis establishment. Prednisolone in combination with estrogen proved an optimal mode for concurrent mucosal infection establishment. The model maintained for 1 week with fungal burden reached at least 10(5) cfu/g of tissue. This mouse model was evaluated by in vivo pharmacodynamics of fluconazole and host mucosal immunity of IL-17 and IL-23. Mice infected by SC5314 were cured by fluconazole. An increase in IL-23 in both oral and vaginal homogenates was observed after infection, while IL-17 only had a prominent elevation in oral tissue. This model could properly mimic complicated clinical conditions and provides a valuable means for antifungal assay in vivo and may also provide a useful method for the evaluation of host-fungal interactions.

Host immune defense against Aspergillus fumigatus: insight from experimental systemic (disseminated) infection

Model of systemic Aspergillus fumigatus infection induced by intravenous application of conidia is suitable for studying important aspects of invasive aspergillosis including relationship between infection and mortality, dissemination of infection and immune mechanisms involved in host resistance to this fungus. Use of this model allows the investigation of both innate and adaptive immune response characteristics in resistant/susceptible host, and investigating the contribution of genetic background and cytokine gene deficiency improves the knowledge of the diversity of mechanisms of immune response to Aspergillus infection. Studying of various aspects of systemic aspergillosis contributes to development of antifungal drugs.