Identifying genetic susceptibility to Aspergillus fumigatus infection using collaborative cross mice and RNA-Seq approach

Background:Aspergillus fumigatus(Af)is one of the most ubiquitous fungi and its infection potency is suggested to be strongly controlled by the host genetic back-ground.The aim of this study was to search for candidate genes associated with host susceptibility to Aspergillus fumigatus(Af)using an RNAseq approach in CC lines and hepatic gene expression.Methods:We studied 31 male mice from 25 CC lines at 8 weeks old;the mice were infected with Af.Liver tissues were extracted from these mice 5 days post-infection,and next-generation RNA-sequencing(RNAseq)was performed.The GENE-E analysis platform was used to generate a clustered heat map matrix.Results:Significant variation in body weight changes between CC lines was ob-served.Hepatic gene expression revealed 12 top prioritized candidate genes differ-entially expressed in resistant versus susceptible mice based on body weight changes.Interestingly,three candidate genes are located within genomic intervals of the previ-ously mapped quantitative trait loci(QTL),including Gm16270 and Stox1 on chromo-some 10 and Gm11033 on chromosome 8.Conclusions:Our findings emphasize the CC mouse model's power in fine mapping the genetic components underlying susceptibility towards Af.As a next step,eQTL analysis will be performed for our RNA-Seq data.Suggested candidate genes from our study will be further assessed with a human cohort with aspergillosis.

CD3ε of a pan T cell marker involved in mouse Aspergillus fumigatus keratitis

AIM:To explore whether CD3ε is involved in the adaptive immunity of Aspergillus fumigatus(A.fumigatus)keratitis in mice and the role of innate and adaptive immunity in it.METHODS:Mice models of A.fumigatus keratitis were established by intra-stromal injection and corneal epithelial scratching.Subconjunctival injections of natamycin,wedelolactone,LOX-1 inhibitor(poly I)or Dectin-1 inhibitor(laminarin)were used to treat mice with A.fumigatus keratitis.Mice were pretreated by intraperitoneal injection of anti-mouse CD3ε.We observed the corneal infection of mice under the slit lamp microscope and made a clinical score.The protein expression of CD3ε and interleukin-10(IL-10)was determined by Western blotting.RESULTS:With the disease progresses,the degree of corneal opacity and edema augmented.In the intrastromal injection models,CD3εprotein expression began to increase significantly on the 2^(nd) day.However,in the scraping epithelial method models,CD3ε only began to increase on the 3^(rd) day.After natamycin treatment,the degree of corneal inflammation in mice was significantly attenuated on the 3^(rd) day.After wedelolactone treatment,the severity of keratitis worsened.And the amount of CD3ε protein was also reduced,compared with the control group.By inhibiting LOX-1 and Dectin-1,there was no significant difference in CD3ε production compared with the control group.After inhibiting CD3ε,corneal ulcer area and clinical score increased,and IL-10 expression was downregulated.CONCLUSION:As a pan T cell marker,CD3ε participate in the adaptive immunity of A.fumigatus keratitis in mice.In our mice models,the corneas will enter the adaptive immune stage faster.By regulating IL-10,CD3ε exerts antiinflammatory and repairs effects in the adaptive immune stage.

北部湾海洋真菌Aspergillus fumigatus DL-p0m-g2的化学成分及药理活性研究

为获得具有生物活性的化合物,对一株分离于北部湾钉螺菌株Aspergillus fumigatus DL-p0m-g2的化学成分及药理活性进行研究。综合应用反相ODS(octadecylsilyl)柱色谱、半制备液相等多种色谱学方法进行分离纯化,根据化合物理化性质、质谱和核磁共振波谱学数据进行结构鉴定,并对分离得到的化合物进行细胞毒活性、抑菌活性和胆固醇转运蛋白NPC1L1(NPC1-like intracellular cholesterol transporter 1)蛋白结合等生物活性评价。实验共分离得到21个生物碱类化合物和1个甾体,分别鉴定为6-methoxyspirotryprostatin B(1)、spirotryprostatin A(2)、fumitremorgin C(3)、cyclotryprostatin A(4)、fumitremorgin B(5)、pseurotin A(6)、azaspirofuran A(7)、azaspirofuran B(8)、cephalimysin C(9)、cephalimysin B(10)、fumiquinazoline C(11)、fumiquinazoline B(12)、fumiquinazoline A(13)、fumiquinazoline D(14)、fumiquinazoline F(15)、tryprostatin B(16)、verruculogen(17)、chaetominine(18)、bisdethiobis(methylthio)glitoxin(19)、helvolic acid(20)、7-deacetylpyripyropene A(21)、terezine D(22)。其中化合物6对人肝癌细胞(Hep G2)、人肺癌细胞(A549)、人直肠癌细胞(HCT116)有一定的细胞毒活性;化合物1、3和20对金黄色葡萄球菌表现出抑菌活性;化合物14与NPC1L1蛋白具有较好的结合,显示其在降脂药物开发中的研究潜力。

水母共附生真菌Aspergillus fumigatus SCSIO41214中生物碱类化合物研究

从水母共附生真菌Aspergillus fumigatus SCSIO41214中分离得到8个已知生物碱类化合物。这些化合物主要采用包括正相硅胶、反相硅胶等常规柱层析技术,以及高效液相色谱进行分离纯化。首次通过核磁共振波谱等多种现代波谱技术确定了化合物1的平面结构,通过单晶衍射技术确定了其相对构型,化合物2-8是通过波谱分析并结合文献数据比对确定了化合物的结构。体外抗炎活性研究筛选发现,化合物4在10μmol·L^(-1)浓度下显示弱的抑制RAW264.7细胞中LPS引起的NO的释放。

真菌Aspergillus fumigatus var .fumigatus的次生代谢产物(英文)

目的:研究西双版纳粗榧共生真菌Aspergillus fumigatusvar .fumigatus的次生代谢产物。方法:通过柱层析法分离发酵产物的化学成分,并利用波谱数据和文献数据对照鉴定化合物的结构。结果:分离到2个化合物,分别鉴定为trypacidin (1)及其衍生物1 ,2-seco-trypacidin (2)。结论:化合物2是新结构;并对文献中关于trypacidin的C-4和C-7a位碳谱数据的指定进行了更正。

海洋来源真菌烟曲霉(Aspergillus fumigatus)次级代谢产物研究(Ⅱ)

对一株海洋来源的微生物（Aspergillus fumigatus.）中的次级代谢产物进行了研究,采用硅胶柱色谱方法进行分离纯化,根据理化性质和光谱数据鉴定了化合物的结构,分别为环-（丙-缬）（1）,环-（色-脯）（2）,N-[2-（4-羟基苯基）乙基]乙酰胺（3）,对羟基苯乙酰胺（4）,4,8-二羟基-1-四氢萘醌（5）,3,4-二羟基苯甲酸甲酯（6）,麦角甾醇（7）和过氧化麦角甾醇（8）。化合物1~8均首次从该菌株中分离。

海洋真菌Aspergillus fumigatus次生代谢产物研究

对来源于腔节藻属海藻Coelarthrumboergesenii（采自中国南海西沙群岛）的一株海洋内生真菌Aspergillusfumigatus的发酵液进行化学成分的分离及鉴定。采用硅胶柱色谱、凝胶柱色谱和高压液相色谱等分离手段，从乙酸乙酯萃取部分中分离得到16个次级代谢产物（1-16），经核磁共振、质谱等现代波谱技术鉴定了它们的结构，分别为gliotoxin （ 1 ）. bis （dethio） bis （methylsulfanyl） gliotoxin （ 2 ）, fumiquinazoline C （ 3 ）. （-） -chaetomium （ 4 ）.verruculogen（5） .fumitremorgin C（6） .brevianamide F（7） .fumigaclavine C（8） .decanedioic acid,2-methylene（9） .decanedioic acid, 2-methylene-, 1-methyl ester （ 10 ）. 2-undecenedioic acid （ 11 ）. 2-undecenedioic acid, 1-methyl ester （ 12 ）. helvolic acid （ 13 ）. di-2-ethyl hexyl phthalate （ 14 ）. physcion （ 15 ）. emodin （16）,其中化合物9、10和12为新天然产物。

越前水母共附生真菌Aspergillus fumigatus sp.次级代谢产物研究

采用硅胶柱层析、Sephadex LH-20凝胶柱层析、中压反相柱层析以及半制备高效液相色谱等方法对韩国南部海岸来源的越前水母共附生真菌A.fumigatus的大米发酵产物进行分离纯化,并利用核磁共振、质谱等波谱学方法结合其理化性质及文献数据鉴定了7个单体化合物的结构:sinulariapeptide C(1)、simplicilliumtide A(2)、simplicilliumtide B(3)、sinulariapeptide D(4)、4-羟基-17 R-甲基降甾醇(5)、3-羟基苯乙酸甲酯(6)、邻苯二甲酸二丁酯(7)。化合物1~7均为首次从越前水母来源的菌属中分离得到。

海洋真菌Aspergillus fumigatus YK-7次级代谢产物的研究

对一株海洋真菌Aspergillus fumigatus YK-7的次级代谢产物进行了分离纯化、结构鉴定和抗肿瘤活性测定。利用硅胶柱色谱、ODS柱色谱、凝胶柱色谱、高效液相色谱等方法从该菌株发酵液的乙酸乙酯萃取物和菌丝体的丙酮提取物中分离得到10个化合物。通过核磁与质谱数据分析结合理化常数鉴定化合物的结构,分别为:5α,8α-过氧-(22E,22R)-麦角甾-6,22-二烯-3β-醇(Ⅰ)、(22E,24R)-麦角甾-8,22-二烯-3β,5α,6β,7α-四醇(Ⅱ)、环(脯-色)二肽(Ⅲ)、环(苯丙-丝)二肽(Ⅳ)、4,8-二羟基-α-四氢萘酮(Ⅴ)、苔黑酚(Ⅵ)、苔黑酚羧酸(Ⅶ)、原儿茶酸(Ⅷ)、2-acetylamino-3,5,14-trihydroxyicos-6-en-4-olide(Ⅸ)、1-单亚油酸甘油酯(Ⅹ)。其中,化合物Ⅸ为新天然产物,化合物Ⅱ、Ⅶ、Ⅷ、Ⅹ从曲霉属真菌中首次分离得到,化合物Ⅳ、Ⅵ从该种真菌中首次分离得到。化合物Ⅳ、Ⅴ、Ⅸ对选定的人肿瘤细胞具有一定的体外抗增殖活性。

Inhibition of LOX-1 alleviates the proinflammatory effects of high-mobility group box 1 in Aspergillus fumigatus keratitis

AIM: To investigate the inflammatory amplification effect of high-mobility group box 1(HMGB1) in Aspergillus fumigatus(A. fumigatus) keratitis and the relationship between lectin-like oxidized low-density lipoprotein receptor 1(LOX-1) and HMGB1 in keratitis immune responses.METHODS: Phosphate buffer saline(PBS), and Boxb were injected into BALB/c mice subconjunctivally before the corneas were infected with A. fumigatus. RAW264.7 macrophages and neutrophils were pretreated with PBS and Boxb to determine the HMGB1 inflammatory amplification effects. Abdominal cavity extracted macrophages were pretreated with Boxb and Poly(I)(a LOX-1 inhibitor) before A. fumigatus hyphae stimulation to prove the the relationship between the two molecules. LOX-1, interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), macrophage inflammatory protein-2(MIP-2) and IL-10 were assessed by polymerase chain reaction and Western blot.RESULTS: Pretreatment with Boxb exacerbated corneal inflammation. In macrophages and neutrophils, A. fumigatus induced LOX-1, IL-1β, TNF-α and MIP-2 expression in Boxb group was higher than those in PBS group. Poly(I) treatments before infection alleviated the proinflammatory effects of Boxb in abdominal cavity extracted macrophages. Pretreatment with Boxb did not influence Dectin-1 mRNA levels in macrophages and neutrophils.CONCLUSION: In fungal keratitis, HMGB1 is a proinflammatory factor in the first line of immune response. HMGB1 mainly stimulates neutrophils and macrophages to produce inflammatory cytokines and chemokines during the immune response. LOX-1 participates in HMGB1 induced inflammatory exacerbation in A. fumigatus keratitis.

The roles of surfactant protein D during Aspergillus fumigatus infection in human corneal epithelial cells

AIM: To investigate roles of surfactant protein D (SP-D) and relative cytokines in human corneal epithelial (HCE) cells Exposed to aspergillus fumigatus (AF) antigens. METHODS: HCE cells cultured 47 in vitro with AF antigens and sampled at 0, 0.5, 1 hour, 2, 4, 6 and 8 hours. The Expression of SP-D mRNA was evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).The expression of SP-D protein was shown by ELISA and immunocytochemistry SP methods. The expression of NF-kappa B and relative downstream cytokines such as TNF-alpha, IL-1 beta, IL-8 and IL-10 in supernatant fluid were measured by ELISA. RESULTS: SP-D mRNA and protein were detected in untreated HCE cells. The expression of SP-D and the relative downstream cytokines rose after being stimulated with AF antigens. SP-D mRNA began to rise at 0.5 hour and the most significantly peak was in 2 hours. The protein of SP-D in supernatant fluid had the same trend with mRNA. Immunocytochemistry of SP-D showed positive expression and gradually increased to 6 hours, and then the expression began to decline. NF-kappa B was activated after treated by AF antigens and the changes had correlation with SP-D. TNF-alpha, IL-1 beta, IL-8 and IL-10 began to rise after given AF antigens 1 hour and were 1.82, 1.43, 1.12 and 1.28 times higher than the untreated HCE cells separately. The expression of TNF-alpha and IL-1 beta reached the peak at 2 hours, separately 2.80 and 2.86 times than the untreated. The expression of IL-8 and IL-10 gradually increased with a time-dependent manner. ' CONCLUSION: HCE cells exists SP-D and it may play a significant role in pathogenesis of keratomycosis. AF may induce human corneal epithelial cells to express inflammatory cytokines via SP-D and NF-kappa B pathway. SP-D possibly mediates the recognition to AF mycelium.

Comparison of four supports for adsorption of reactive dyes by immobilized Aspergillus fumigatus beads

Four materials, sodium carboxymethylcellulose （Na-CMC）, sodium alginate （SA）, polyvinyl alcohol （PVA）, and chitosan （CTS）, were prepared as supports for entrapping fungus Aspergillusfumigatus. The adsorption of synthetic dyes, Reactive Brilliant Blue KN- R, and Reactive Brilliant Red K-2BP, by these immobilized gel beads and plain gel beads was evaluated. The adsorption efficiencies of Reactive Brilliant Red K-2BP and Reactive Brilliant Blue KN-R by CTS immobilized beads were 89.1% and 93.5% in 12 h, respectively. The adsorption efficiency by Na-CMC immobilized beads was slightly lower than that of mycelial pellets. But the dye culture mediums were almost completely decolorized in 48 h using the above-mentioned two immobilized beads （exceeding 95%）. The adsorption efficiency by SA immobilized beads exceeded 92% in 48 h. PVA-SA immobilized beads showed the lowest adsorption efficiency, which was 79.8% for Reactive Brilliant Red K-2BP and 92.5% for Reactive Brilliant Blue KN-R in 48 h. Comparing the adsorption efficiency by plain gel beads, Na-CMC plain gel beads ranked next to CTS ones. SA and PVA-SA plain gel beads hardly had the ability of adsorbing dyes. Subsequently, the growth of mycelia in Na-CMC and SA immobilized beads were evaluated. The biomass increased continuously in 72 h. The adsorption capacity of Reactive Brilliant Red K-2BP and Reactive Brilliant Blue KN-R by Na-CMC immobilized beads was 78.0 and 86.7 mg/g, respectively. The SEM micrographs show that the surface structure of Na-CMC immobilized bead is loose and finely porous, which facilitates diffusion of the dyes.

Role of the IL-33/ST2/p38 signaling pathway in the immune response of corneal epithelial cells to Aspergillus fumigatus infection

AIM: To investigate the expression of interleukin(IL)-33 in the cornea and human corneal epithelial cells(HCECs) exposed to Aspergillus fumigatus(A. fumigatus), and to determine the function of IL-33/ST2/p38 signaling pathway in the immune response of corneal epithelial cells to A. fumigatus infection.METHODS: The mRNA and protein expression of IL-33 in HCECs and mice corneas were examined by quantitative real-time reverse transcription polymerase chain reaction(q RT-PCR) and Western blot analysis, respectively. IL-33 expression was also detected in cornea samples from healthy donors and patients with fungal keratitis with immunohistochemistry. The cultured HCECs were treated with inactive A. fumigatus hyphae at various concentrations with or without recombinant human IL-33 protein, soluble recombinant ST2 protein, specific ST2 neutralizing antibody, or the mitogen-activated protein kinase(MAPK) p38 inhibitor SB203580 for evaluation of the expression and activation of IL-33/ST2/p38 signaling in the regulation of proinflammatory cytokines. The production levels of IL-6 and IL-1β were determined by qR T-PCR and enzymelinked immunosorbent assay(ELISA). The proliferation of HCECs was determined by a Cell Counting Kit-8(CCK8) assay and cell count.RESULTS: IL-33 expression levels increased in the corneal tissues of patients with fungal keratitis and in mice corneas of experimental A. fumigatus infection,as well as in HCECs with infection of A. fumigatus. A. fumigatus strongly stimulated HCECs-generated proinflammatory cytokine(IL-6 and IL-1β) production at both the mRNA and protein levels. This production of proinflammatory mediators stimulated by A. fumigatus was further stimulated by IL-33 and was prevented by soluble ST2 protein or ST2 neutralizing antibody. Moreover, IL-33 naturally promoted the p38 phosphorylation induced by A. fumigatus, which was suppressed by soluble ST2 protein. The MAPK p38 inhibitor SB203580 also inhibited the A. fumigatus-induced proinflammatory cytokine production. IL-33 administration for 48 h and 72 h promoted the proliferation of HCECs, which was attenuated by treatment with soluble recombinant human ST2 protein.CONCLUSION: A. fumigatus elevates IL-33 expression in human and mice corneas and HCECs. Thus, IL-33/ST2/p38 signaling may play an important role in amplifying the immune response of corneal epithelial cells to A. fumigatus infection. Besides, IL-33 promotes the cell proliferation of HCECs via its receptor ST2. These findings suggest a novel autocrine mechanism of amplification of the fungalinduced inflammatory response in the corneal epithelium, highlighting a potential therapeutic target for fungal keratitis.

海南东寨港红树林内生真菌Aspergillus fumigatus SAS10吡喃酮类代谢产物

采用大米培养基,对无瓣海桑内生真菌Aspergillus fumigatus SAS10进行静置发酵,运用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、以及半制备高效液相等分离手段对发酵产物进行分离纯化,获得7个化合物。经分析质谱、核磁等波谱数据,并通过与文献对比鉴定化合物为:aspergyllone(1),(R)-2-(羟基(苯基)甲基)-4H-吡喃-4-酮(2),carbonarone A(3),campyrone A(4),campyrone C(5),asperfurandione A(6)和dibutylterephthalate(7)。所得7个化合物均为首次报道为烟曲霉次级代谢产物。

Dectin-1 expression at early period of Aspergillus fumigatus infection in rat's corneal epithelium

AIM:To investigate the expression of dendritic cell-associated C-type lectin-1 (dectin-1) at the early period of Aspergillus fumigatus infection in rat’s corneal epithelium. ·METHODS:A total of 72 Wistar rats were randomly divided into three groups:A, B and C. The right eyes were chosen as experimental eyes. Group A was control group. Rats in group B were not inoculated with Aspergillus fumigatus. Group C was taken as Aspergillus fumigatus keratitis model. Rats in group B and C (six from each group) were executed randomly at 4, 8, 16 and 24 hours after experimental model being established to assess the expression of dectin-1 mRNA through real-time PCR. Another six rats in group B and C were executed randomly at 24 hours to assess the expression of dectin-1 protein through immunohistochemistry. ·RESULTS:The results of real-time PCR indicated that dectin-1 mRNA expression was low in corneal epithelium of normal rats’. There was no significantly difference of dectin-1 mRNA expression in group A and B (P 】0.05). The expression of Aspergillus fumigatus infected corneal epithelium increased gradually after 8 hours in group C. The synchronous expression of group A and C had significant difference (P 【0.01). Immunohistochemisty discovered that dectin-1 receptor existed in normal rat’s corneal epithelium . Dectin-1 protein increased after 24 hours in group C. There was a significant difference of synchronous expression in group B and C(P【0.01). · CONCLUSION:Dectin-1 exists in rat’s cornealepithelium and its expression significantly increases at the early period of Aspergillus fumigatus infection. Dectin-1 is a pattern recognition receptor that expresses in corneal epithelium and involves in immune response to Aspergillus fungal keratitis.

Expression and role of aryl hydrocarbon receptor in Aspergillus fumigatus keratitis

●AIM:To observe the expression and role of aryl hydrocarbon receptor(Ah R)in the immune response of mouse cornea infected with Aspergillus fumigatus(A.fumigatus).●METHODS:Murine models of A.fumigatus keratitis were established by scraping the central epithelium of mouse cornea,daubing A.fumigatus on the cornea and covering with a contact lens.The mice were randomly divided into the control group and the A.fumigatus-infected(A.F.)group for 1,3 and 5 d respectively,which corneas were daily monitored by a slit lamp microscope and the clinical scores were also recorded timely after infection.In this study,immunofluorescence staining was used to detect the expression and localization of Ah R in mouse corneas,and the m RNA and protein of Ah R were detected by reverse transcription-polymerase chain reaction(RT-PCR)and Western blot.In addition,mouse peritoneal macrophages were stimulated by A.fumigatus with or without the pretreatment of Ah R antagonist CH223191 and Ah R agonist FICZ,and the tumor necrosis factor alpha(TNF-α),inducible nitric oxide synthase(i NOS),interleukin-10(IL-10)and Arg-1 m RNA were detected by RT-PCR.●RESULTS:According to the results of the slit light photography,it was clearly indicated that the corneal inflammation were the most severe and the clinical score became the highest as well on the 3 rd day after the infection of A.fumigatus.Contrasted with the control group,the expression of Ah R in the corneal epithelial cells infected with A.fumigatus was significantly increased detected by immunofluorescence staining.Ah R mainly expressed in the nucleus and cytoplasm of corneal epithelial cells.Consistent with the transcriptional level of Ah R m RNA,the expression level of Ah R protein reached the peak on the 3 rd day after infection which was detected by Western blot.Furthermore,RT-PCR showed that CH223191 up-regulated the expression of TNF-αand i NOS and down-regulated the expression of IL-10 and Arg-1 in peritoneal macrophages;inversely,FICZ reduced the expression of TNF-αand i NOS while elevated the expression of IL-10 and Arg-1.●CONCLUSION:Ah R is involved in the pathogenesis of A.fumigatus keratitis and induced immune protection in anti-A.fumigatus immune response by inhibiting M1 and increasing M2 phenotype macrophage-related inflammatory factors.

Nucleotide oligomerization domain 2 contributes to the innate immune response in THCE cells stimulated by Aspergillus fumigatus conidia

AIM: To investigate the expression of nucleotide oligomerization domain 2 (NOD2) in the immortalized human corneal epithelial cell line (THCE), and its role in the innate immune response triggered by inactive Aspergillus fumigatus (Af) conidia. METHODS: The normal THCE cells were investigated as controls. After incubation with inactive Af conidia for 0.5, 2, 4, 6, and 8 hours, THCE cells were harvested, mRNA expression of NOD2 and receptor interacting protein 2 (RIP2) was detected by RT-PCR. Intracellular proteins including NOD2, NF-kappa B and proinflammatory cytokines such as TNF-alpha, IL-8, IL-6 in the cell supernatant were analyzed by ELISA. RESULTS: Our data indicate that NOD2 expressed in the normal THCE cells. After triggered by the inactive Af conidia, the expression of NOD2, RIP2 mRNA and the secretion of NOD2, NF-kappa B, TNF-alpha, IL-8, IL-6 both increased in a time-depended manner, and reached the peak point at 4, 6, 6, 4, 6, 6, 4 hours, respectively. And after pretreated with NOD2 neutralizing antibody, the expression of RIP2, NF-kappa B, TNF-alpha, IL-8 both decreased dramatically at the peak point, while the secretion of IL-6 changed little. CONCLUSION: The results of this study suggest that NOD2 exists and expresses in the THCE cells, and contributes to the innate immune responses triggered by inactive Afconidia by induction of proinflammatory cytokines such as TNF-alpha and IL-8 through the NF-kappa B pathway.

Expression of macrophage migration inhibitory factor in Aspergillus fumigatus keratitis

AIM: To investigate the expression of macrophage migration inhibitory factor(MIF) and detect its role in the innate immune response of fungal keratitis(FK). METHODS: We collected the paraffin-embedded cornea tissues from 10 FK and 6 ocular trauma patients to explore the MIF expression by immunohistochemistry. Then we cultured telomease-immortalized human corneal epithelial cells(THCEs), stimulated by the hyphae suspension of Aspergillus fumigatus(A. fumigatus) to detect the change of MIF with or without the pretreatment of MIF inhibitor [4-Iodo-6-phenylpyrimidine(4-IPP)] by real-time polymerase chain reaction(PCR). The protein level of MIF was also tested by immunohistochemistry, and the level of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) mRNA were compared between normal, hyphae stimulated and 4-IPP pretreated groups by real-time PCR to study the influence of MIF on the expression of TNF-α and IL-6. Corneal severity of rats' FK models was documented by clinical scores, and real-time PCR. Western blot and immunohistochemistry were used to test the expression of MIF, TNF-α and IL-6 in rats' corneas.RESULTS: In the corneas of FK patients, there was much stronger expression of MIF than that in the normal group showed by immunohistochemistry. In cultured THCEs stimulated by A. fumigatus, the expression of MIF became stronger in both immunohistochemistry and PCR at 16, 24, 32 and 48 h post infection(p.i.; P<0.01, P<0.01, P<0.01, P<0.05). After pretreated with 4-IPP, the expression of MIF reduced at 4, 8, 16 h p.i.(P<0.05, P<0.05, P<0.05) and the downstream TNF-α and IL-6 decreased obviously(P<0.05, P<0.01). In rats with A. fumigatus keratitis, the relative mRNA and protein level of MIF increased than thosein the normal group by PCR(at 1 d: P<0.01, 3 d: P<0.01, 5 d: P<0.01), Western blot and immunohistochemistry. After blocked MIF with 4-IPP, the clinical outcomes of rat keratitis showed markedly reduced inflammatory response(P<0.01), with TNF-α and IL-6 decreased in accordance with those in THCEs by PCR(P<0.05, P<0.01). CONCLUSION: The expression of MIF increased significantly in FK patients, THCEs and rats stimulated by A. fumigatus. After blocked with 4-IPP, the expression of MIF reduced, and so did its downstream cytokines: TNF-α and IL-6. The inflammation reaction of the rats' corneas lightened after pretreated with 4-IPP. MIF may play a role in the innate immune response of the corneal resistance against A. fumigatus.

Expression of indoleamine 2,3-dioxygenase in a murine model of Aspergillus fumigatus keratitis

AIM： To observe the presence and expression of indoleamine 2,3-dioxygenase（IDO） during the corneal immunity to Aspergillus fumigatus（A. fumigatus） in the murine models.·METHODS： The murine model of fungal keratitis was established by smearing with colonies of A. fumigatus after scraping central epithelium of cornea and covering with contact lenses in C57BL/6 mice. The mice were randomly divided into control group, sham group and A.fumigatus keratitis group. The cornea was monitored daily using a slit lamp and recorded disease score after infection. Corneal lesion was detected by immunofluorescence staining. IDO m RNA and protein were also detected by quantitative reverse transcription-polymerase chain reaction（q RT-PCR） and Western blot.· RESULTS： The disease score and slit lamp photography indicated that disease severity was consistent with corneal inflammation in the murine models, and the disease scores in A. fumigatus keratitis group were obviously higher than those in the sham group. By immunofluorescence staining, IDO was mainly localized in corneal epithelium and stroma in the murine corneal tissues with A. fumigatus keratitis. Compared with the sham group, IDO m RNA expression was significantly enhanced in corneal epithelium infected by A. fumigatus. Furthermore, IDO protein expression detected by Western blot was in accord with transcript levels of IDO m RNA measured by q RT-PCR. IDO protein expression was enhanced after A. fumigatus infection compared with the sham group.·CONCLUSION： IDO is detected in corneal epithelium and stroma locally, which indicates IDO takes part in the pathogenesis of A. fumigatus keratitis and plays a key role in immune regulation at the early stage.

Regulation of lipoxygenase-1 and Dectin-1 on interleukin-10 in mouse Aspergillus fumigatus keratitis

AIM： To investigate the regulation of lipoxygenase （LOX）-1 and Dectin-1 on interleukin-10 （IL-10） production in mice with Aspergillus fumigatus （A. fumigatus） keratitis. METHODS： The corneas of C57BL/6 mice were pretreated with LOX-1 inhibitor Poly（I） or Dectin-1 siRNA separately before the infection of A. fumigatus. Polymerase chain reaction （PCR） and Western blot were used to detect the expression of IL-10. RESULTS： The mRNA and protein expressions of IL-10 were significantly increased in mice with A. fumigatus keratitis. Compared with the group pretreated with sterile water before infection, Poly（I） pretreatment suppressed IL-10 expression significantly. Compared with the group pretreated with scrambled siRNA before infection, Dectin-1 siRNA pretreatment significantly reduced IL-10 expression in response to A. fumigatus infection. CONCLUSION： LOX-1 and Dectin-1 regulate IL-10 production in mouse A. fumigatus keratitis.