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Background Alzheimer's disease presents an abnormal cognitive behavior. TgCtwh6 is one of the predominant T. gondii strains prevalent in China. Although T. gondii type II strain infection can cause host cognitive behavioral abnormalities, we do not know whether TgCtwh6 could also cause host cognitive behavioral changes. So, in this study, we will focus on the effect of TgCtwh6 on mouse cognitive behavior and try in vivo and in vitro to explore the underlying mechanism by which TgCtwh6 give rise to mice cognitive behavior changes at the cellular and molecular level. Methods C57BL/6 mice were infected orally with TgCtwh6 cysts. From day 90 post-infection on, all mice were conducted through the open field test and then Morris water maze test to evaluate cognitive behavior. The morphology and number of cells in hippocampus were examined with hematoxylin-eosin (H&E) and Nissl staining; moreover, Aβ protein in hippocampus was determined with immunohistochemistry and thioflavin S plaque staining. Synaptotagmin 1, apoptosis-related proteins, BACE1 and APP proteins and genes from hippocampus were assessed by western blotting or qRT-PCR. Hippocampal neuronal cell line or mouse microglial cell line was challenged with TgCtwh6 tachyzoites and then separately cultured in a well or co-cultured in a transwell device. The target proteins and genes were analyzed by immunofluorescence staining, western blotting and qRT-PCR. In addition, mouse microglial cell line polarization state and hippocampal neuronal cell line apoptosis were estimated using flow cytometry assay. Results The OFT and MWMT indicated that infected mice had cognitive behavioral impairments. The hippocampal tissue assay showed abnormal neuron morphology and a decreased number in infected mice. Moreover, pro-apoptotic proteins, as well as BACE1, APP and Aβ proteins, increased in the infected mouse hippocampus. The experiments in vitro showed that pro-apoptotic proteins and p-NF-κBp65, NF-κBp65, BACE1, APP and Aβ proteins or genes were significantly increased in the infected HT22. In addition, CD80, pro-inflammatory factors, notch, hes1 proteins and genes were enhanced in the infected BV2. Interestingly, not only the APP and pro-apoptotic proteins in HT22, but also the apoptosis rate of HT22 increased after the infected BV2 were co-cultured with the HT22 in a transwell device. Conclusions Neuron apoptosis, Aβ deposition and neuroinflammatory response involved with microglia polarization are the molecular and cellular mechanisms by which TgCtwh6 causes mouse cognitive behavioral abnormalities. Graphical Abstract

Background Toxoplasma gondii is a neurotropic single-celled parasite that can infect mammals, including humans. Central nervous system infection with T. gondii infection can lead to Toxoplasma encephalitis. Toxoplasma infection can cause endoplasmic reticulum (ER) stress and unfolded protein response (UPR) activation, which ultimately can lead to apoptosis of host cells. The dense granule protein GRA3 has been identified as one of the secretory proteins that contribute to the virulence of T. gondii; however, the mechanism remains enigmatic. Methods The expression of the GRA3 gene in RH, ME49, Wh3, and Wh6 strains was determined using quantitative real-time polymerase chain reaction (qRT–PCR). pEGFP-GRA3Wh6 was constructed by inserting Chinese 1 Wh6 GRA3 (GRA3Wh6) cDNA into a plasmid encoding the enhanced GFP. Mouse neuro2a (N2a) cells were transfected with either pEGFP or pEGFP-GRA3Wh6 (GRA3Wh6) and incubated for 24–36 h. N2a cell apoptosis and ER stress-associated proteins were determined using flow cytometry and immunoblotting. Furthermore, N2a cells were pretreated with GSK2656157 (a PERK inhibitor) and Z-ATAD-FMK (a caspase-12 inhibitor) before GRA3Wh6 transfection, and the effect of the inhibitors on GRA3Wh6-induced ER stress and apoptosis were investigated. Results GRA3 gene expression was higher in the less virulent strains of type II ME49 and type Chinese 1 Wh6 strains compared with the virulent strains of type I RH strain and type Chinese 1 Wh3 strain. Transfection with GRA3Wh6 plasmid induced neuronal apoptosis and increased the expression of GRP78, p-PERK, cleaved caspase-12, cleaved caspase-3, and CHOP compared with the control vector. Pretreatment with GSK2656157 and Z-ATAD-FMK decreased apoptosis in N2a cells, and similarly, ER stress- and apoptosis-associated protein levels were significantly decreased. Conclusion GRA3 induces neural cell apoptosis via the ER stress signaling pathway, which could play a role in toxoplasmic encephalitis. Graphical Abstract

Recombinant SjCystatin (rSjCystatin), a recombinant protein of Schistosoma japonicum cystatin, has been reported to have an effect on immunoregulation mediated by IL-10 induction. Rheumatoid arthritis (RA) is a common autoimmune inflammatory arthropathy, and recombinant immune-modulating drugs for RA treatment are under development. We aimed to study the putative immune regulation of rSjCystatin and its prophylactic/therapeutic effects on murine collagen-induced arthritis (CIA). CIA was induced in DBA/1 mice by inoculation with bovine collagen II (CII). rSjCystatin was administered prior or post development of CIA. The severity of CIA was assessed using established clinical and histopathological scoring systems. The incidence was also determined. The CII-specific antibodies in sera and cytokines in splenocyte culture supernatants were measured by ELISA. Th1/Th2/Th17 cells and Tregs development in splenocytes were monitored by flow cytometry. The inflammatory mediators in the diseased joint were semiquantitated by qPCR. Prophylactic injection of rSjCystatin attenuated paw clinical scores, incidence, and histopathology scores of joints in CIA mice. The arthritis-alleviative effects were closely associated with the augmentation of IL-4, IL-10, and collagen-specific IgG1, and with the distinct reduction of IFN-γ, collagen-specific IgG2a, and the marked decrease of proinflammatory cytokines IL-6, IL-17, and TNF-α and RANKL. The data indicate that rSjCystatin may prevent cartilage destruction and inflammation of joints in CIA mice. The effects are related to the inhibitory modulation of Th1 and Th17 and upregulation of Tregs and Th2 via a shift of cytokines profiling from Th1 to Th2 response.

To report a rare case of extensive bilateral xanthelasma palpebrarum (XP). A 70-year-old man presented with nodular lesions of his eyelids for 12 years. The skin changes began with his left lower eyelid and progressively spread to both lateral-inferior and infero-medial periorbital areas. The lesions were yellow nodules that were hard, extensive, multiple and coalescent. The tumors of this patient’s eyelids underwent resection and tissue was processed for light microscopic examination. Under light microscopy, many foamy xanthoma cells were found in the dermis, often nested around capillaries. Touton giant cell were also be observed, and tissue fibrous hyperplasia was obvious. The pathological changes were seen in the orbicularis oculi muscle, where many foamy xanthoma cells were seen between the muscle fibers. XP is the most common cutaneous xanthoma and typically presents in the middle-aged and elderly. This presentation of XP is notable because of its extent. The light microscopic appearance confirmed the diagnosis of XP. Surgical intervention provided substantial cosmesis.

Background Toxoplasma gondii, a single-celled parasite commonly found in mammals, has been shown to induce trophoblast cell apoptosis and subsequently cause fetal damage and abortion. Although dense granule protein 15 (GRA15) has been identified as a key component in innate immunity to T. gondii infection and its pathogenesis, its role in host cell apoptosis remains unclarified. Methods Type II GRA15 (GRA15II) cDNA was inserted into a plasmid encoding enhanced green fluorescent protein (pEGFP). Choriocarcinoma JEG-3 cells were transfected with either pEGFP or pEGFP-GRA15II and cultured for 24 h. Cell apoptosis and endoplasmic reticulum stress (ERS) responses were assessed. Inhibitors targeting inositol-requiring kinase 1α (IRE1α; 4μ8C, 100 nM) or c-Jun N-terminal kinase (JNK; SP6000125, 20 μM) were added 12 h after plasmid transfection, followed by testing the effect of GRA15II on ERS. Results When compared to pEGFP, pEGFP-GRA15II transfection facilitated cell apoptosis (P < 0.05), increased mRNA expression of caspase-3, caspase-4, 78-kDa glucose-regulated protein (GRP78), C/EBP homologous protein (CHOP) and X-box binding protein-1 (XBP1) (all P < 0.05), and promoted protein expression of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase, Bax, CHOP, GRP78, phospho-JNK, and phospho-IRE1α (all P < 0.05). The 4μ8C and SP6000125 decreased apoptosis and protein expression of XBP1s, CHOP, TNF receptor-associated factor 2 (TRAF2), phosphorylated apoptosis signal-regulating kinase 1 (ASK1), cleaved caspase-3, phospho-JNK, and Bax (all P < 0.05) in pEGFP-GRA15II transfected cells. Conclusions Toxoplasma GRA15II induced ERS and subsequently caused apoptosis of choriocarcinoma JEG-3 cells.

Background Toxoplasma gondii is an opportunistic protozoan apicomplexan and obligate intracellular parasite that infects a wide range of animals and humans. Rhoptry proteins 5 (ROP5), ROP16, ROP18 and dense granules 15 (GRA15) are the important effectors secreted by T. gondii which link to the strain virulence for mice and modulate the host’s response to the parasite. Little has been known about these molecules as well as GRA3 in type Chinese 1 strains that show polymorphism among strains of archetypical genotypes. This study examined the genetic diversity of these effectors and its correlated virulence in mice among T. gondii isolates from China. Results Twenty-one isolates from stray cats were detected, of which 15 belong to Chinese 1, and 6 to ToxoDB #205. Wh6 isolate, a Chinese 1 strain, has an avirulent phenotype. PCR-RFLP results of ROP5 and ROP18 presented few variations among the strains. Genotyping of GRA15 and ROP16 revealed that all the strains belong to type II allele except Xz7 which carries type I allele. ROP16 amino acid alignment at 503 locus demonstrated that 17 isolates are featured as type I or type III (ROP16I/III), and the other 4 as type II (ROP16II). The strains investigated may be divided into four groups based on GRA3 amino acid alignment, and all isolates of type Chinese 1 belong to the μ-1 allele except Wh6 which is identical to type II strain. Conclusions PCR-RFLP and sequence alignment analyses of ROP5, ROP16, ROP18, GRA3, and GRA15 in T. gondii revealed that strains with the same genotype may have variations in some of their key genes. GRA3 variation exhibited by Wh6 strain may be associated with the difference in phenotype and pathogenesis. Electronic supplementary material The online version of this article (10.1186/s13071-017-2527-4) contains supplementary material, which is available to authorized users.

We investigated the effects of respiratory syncytial virus (RSV) infections on ovalbumin (OVA)-challenged mice via regulation of Th17/Treg cell responses. BALB/c mice were challenged with OVA, followed by RSV infections twice. In OVA-challenged mice, the secretion of Th2/Th17-type cytokines, airway hyperresponsiveness and inflammation were significantly inhibited by initial RSV infection. Moreover, the in vivo findings demonstrated that initial RSV infection reversed the imbalance of Th17/Treg responses. In contrast, RSV re-infection strengthened Th2/Th17-type cytokine secretion, airway hyperresponsiveness, and inflammation, especially for lymphocyte infiltration in OVA-challenged mice. Meanwhile, RSV re-infection enhanced the imbalanced Th17/Treg responses. Upon all results reveal that RSV-induced respiratory infections may lead to dual effects pertaining to allergic airway inflammation by regulation of Th17/Treg responses.

As one of food-borne parasitic diseases, toxoplasmosis entails the risk of developing reactivation in immunocompromised patients. The synthetic dipeptide pidotimod is a potent immunostimulating agent that improves the immunodefenses in immunodepression. To investigate the efficacy of pidotimod as a preventive treatment, we used a murine model of reactivated toxoplasmosis with cyclophosphamide (CY)-induced immunosuppression. Pidotimod administration significantly restored the body weight and spleen organ index, increased survival time (from 70 to 90 %), and decreased the parasitemia (from 80 to 35 %) of CY-induced mice with reactivated toxoplasmosis. Cytokine profiles and CD4+ T cells subpopulation analyses by Cytometric Bead Array and flow cytometry demonstrated that pidotimod treatment resulted in a significant upregulation of pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-2) and Th1 cells (from 3.73 ± 0.39 to 5.88 ± 0.46 %) after CY induction in infected mice. Additionally, histological findings and parasite DNA quantification revealed that mice administered with pidotimod had a remarkable reduction of parasite burden (two-log) and amelioration of histopathology in the brains. The in vitro studies showed that pidotimod significantly restored concanavalin A-induced splenocyte proliferation and pro-inflammatory cytokines in the supernatants of splenocyte culture. It could be concluded that the administration of pidotimod in immunocompromised mice significantly increases the Th1-biased immune response, prolongs survival time, and ameliorates the load of parasites in the blood. This is the first report of the preventive effect of pidotimod on reactivated toxoplasmosis.

Background Loki zupa (Luooukezupa) decoction, consisting of the roots of Hyssopuscuspidatus Boriss (Shenxiangcao) and Irishalophila Pall root (Yuanweigen), is commonly used in Uygur medicine to treat asthma. However, the mode of action of this material has yet to be elucidated. This study aims to investigate the effects of Loki zupa decoction on the airway inflammation of an ovalbumin (OVA)-induced asthma mouse model. Methods Mice were divided into normal control (NC), asthma (A), high, medium and low doses of Loki zupa decoction (L 14.0, L 7.0, L 3.5), water extract (LW), n-butanol extract (LN), ethyl acetate extract (LE) and dexamethasone (DEX) groups. Antiasthmatic model was induced by OVA sensitization and challenged using BALB/c mice. Airway hyperresponsiveness (AHR) toward methacholine (Mch) was assessed using Buxco equipment. Lung inflammation was measured by hematoxylin and eosin staining and bronchoalveolar lavage fluid (BALF) cell count and classification. Inflammatory cytokines in BALF and serum were analyzed by Bio-Plex assay, and mRNA levels were investigated by qPCR analysis. The roots of H. Boriss (250 g) and I. Pall (250 g) were decocted, concentrated and diluted to 14.0, 7.0 and 3.5 g crude herb/kg body weight. The LW, LN and LE of the Loki zupa decoction were prepared and diluted to a dose equivalent to 7 g of crude herb/kg body weight. Results Loki zupa decoction and its extracts significantly attenuated the AHR towards Mch (all P

Background Toxoplasma gondii is an intracellular protozoan that affects most species of endothermic animals including humans with a great infection rate. The vertical transmission of T. gondii causes abortion, constituting a serious threat to humans and leading to great losses in livestock production. Distinct from population structure of T. gondii in North America and Europe, Chinese 1 (ToxoDB #9) is a dominant genotype prevalent in China. Among the isolates of Chinese 1, the Wh3 and Wh6 have different virulence and pathogenicity in mice. However, little has been known about their difference at the genomic level. Thus the next-generation sequencing (NGS) approach was used to discover the association of the phenotypical variations with the genome sequencing data and the expression and polymorphisms of the key effectors. Results We successfully sequenced the genome of Chinese 1 strains of Wh3 and Wh6. The average sequencing depths were 63.91 and 63.61 for Wh3 and Wh6, respectively. The variations of both isolates were identified in comparison with reference genome of type I GT1 strain. There were 505,645 and 505,856 SNPs, 30,658 and 30,004 indels, 4661 and 2320 SVs, and 1942 and 3080 CNVs for Wh3 and Wh6, respectively. In target search variations of particular factors of T. gondii, the dense granule protein 3 (GRA3) and rhoptry neck protein 3 (RON3) were found to have 35 SNPs, 2 indels and 89 SNPs, 6 indels, respectively. GRA3 and RON3 were both found to have higher expression levels in less virulent Wh6 than in virulent Wh3. Both strains of type Chinese 1 share polymorphic GRA15II and ROPI/III with type I, II, and III strains. Conclusions Sequencing of the two strains revealed that genome structure of Chinese 1 and type I strains has considerable genomic variations. Sequencing and qRT-PCR analyses of 26 effectors displayed a remarkable variation that may be associated with phenotype and pathogenic differences. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2106-z) contains supplementary material, which is available to authorized users.