Streptococcus mutans (S. mutans), a major aetiologic agent of dental caries, is involved in systemic diseases, such as bacterial endocarditis, if it enters the bloodstream through temporary bacteraemia. Interleukin (IL)-1β, a proinflammatory cytokine, is related to the host defences against pathogens, and its synthesis, maturation, and secretion are tightly regulated by the activation of the inflammasome, an inflammatory signalling complex. This study examined the signalling mechanism of IL-1β secretion and the inflammasome pathway induced by S. mutans to explain the molecular mechanism through which systemic infection by oral streptococci can occur. After infection of THP-1 cells with S. mutans, the expression of inflammasome components was detected using various methods. S. mutans induced IL-1β secretion via caspase-1 activation, and S. mutans-induced IL-1β secretion required absent in melanoma (AIM2), NLR family pyrin domain-containing 3 (NLRP3) and NLR family CARD domain-containing 4 (NLRC4) inflammasome activation. In particular, the S. mutans-induced NLRP3 inflammasome was mediated by adenosine triphosphate (ATP) release, potassium depletion and lysosomal damage. Our study provides novel insight into the innate immune response against S. mutans infection.
Blotting, Western ; CARD Signaling Adaptor Proteins ; immunology ; Calcium-Binding Proteins ; immunology ; Caspase 1 ; immunology ; DNA-Binding Proteins ; immunology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunity, Innate ; Inflammasomes ; immunology ; Interleukin-1beta ; immunology ; Macrophages ; immunology ; NLR Family, Pyrin Domain-Containing 3 Protein ; immunology ; Signal Transduction ; Streptococcus mutans ; immunology ; Tumor Necrosis Factor-alpha ; immunology

OBJECTIVETo investigate the effect of heat shock factor 1 (HSF1) on airway hyperresponsiveness and airway inflammation in mice with asthma and possible mechanisms.

METHODSA total of 36 mice were randomly divided into four groups: control, asthma, HSF1 small interfering RNA negative control (siHSF1-NC), and siHSF1 intervention (n=9 each). Ovalbumin (OVA) sensitization and challenge were performed to induce asthma in the latter three groups. The mice in the siHSF1-NC and siHSF1 groups were treated with siHSF1-NC and siHSF1, respectively. A spirometer was used to measure airway responsiveness at 24 hours after the last challenge. The direct count method was used to calculate the number of eosinophils. ELISA was used to measure the serum level of OVA-specific IgE and levels of interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), and interferon-γ (IFN-γ) in lung tissues and bronchoalveolar lavage fluid (BALF). Quantitative real-time PCR was used to measure the mRNA expression of HSF1 in asthmatic mice. Western blot was used to measure the protein expression of HSF1, high-mobility group box 1 (HMGB1), and phosphorylated c-Jun N-terminal kinase (p-JNK).

RESULTSThe asthma group had significant increases in the mRNA and protein expression of HSF1 compared with the control group (P<0.05). The siHSF1 group had significantly reduced mRNA and protein expression of HSF1 compared with the siHSF1-NC group (P<0.05). The knockdown of HSF1 increased airway wall thickness, airway hyperresponsiveness, OVA-specific IgE content, and the number of eosinophils (P<0.05). Compared with the siHSF1-NC group, the siHSF1 group had significantly increased levels of IL-4, IL-5, and IL-13 and significantly reduced expression of IFN-γ in lung tissues and BALF (P<0.05), as well as significantly increased expression of HMGB1 and p-JNK (P<0.05).

CONCLUSIONSKnockdown of HSF1 aggravates airway hyperresponsiveness and airway inflammation in asthmatic mice, and its possible mechanism may involve the negative regulation of HMGB1 and JNK.

Animals ; Asthma ; etiology ; Bronchial Hyperreactivity ; etiology ; immunology ; Cytokines ; biosynthesis ; DNA-Binding Proteins ; analysis ; physiology ; Eosinophils ; physiology ; Female ; HMGB1 Protein ; analysis ; Heat Shock Transcription Factors ; Immunoglobulin E ; blood ; Mice ; Mice, Inbred BALB C ; Transcription Factors ; analysis ; physiology

The host takes use of pattern recognition receptors (PRRs) to defend against pathogen invasion or cellular damage. Among microorganism-associated molecular patterns detected by host PRRs, nucleic acids derived from bacteria or viruses are tightly supervised, providing a fundamental mechanism of host defense. Pathogenic DNAs are supposed to be detected by DNA sensors that induce the activation of NFκB or TBK1-IRF3 pathway. DNA sensor cGAS is widely expressed in innate immune cells and is a key sensor of invading DNAs in several cell types. cGAS binds to DNA, followed by a conformational change that allows the synthesis of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) from adenosine triphosphate and guanosine triphosphate. cGAMP is a strong activator of STING that can activate IRF3 and subsequent type I interferon production. Here we describe recent progresses in DNA sensors especially cGAS in the innate immune responses against pathogenic DNAs.
DNA, Bacterial ; immunology ; metabolism ; DNA, Viral ; immunology ; metabolism ; Gene Expression Regulation ; Host-Pathogen Interactions ; Humans ; Immunity, Innate ; Interferon Regulatory Factor-3 ; genetics ; immunology ; Interferon Type I ; biosynthesis ; immunology ; Membrane Proteins ; genetics ; immunology ; Models, Molecular ; NF-kappa B ; genetics ; immunology ; Nucleotides, Cyclic ; biosynthesis ; immunology ; Nucleotidyltransferases ; genetics ; immunology ; Protein Binding ; Protein-Serine-Threonine Kinases ; genetics ; immunology ; Signal Transduction

OBJECTIVETo study the roles of follicular helper T (Tfh) cells and follicular regulatory T (Tfr) cells in the pathogenesis of Henoch-Schönlein purpura (HSP) in children.

METHODSPeripheral blood samples were collected from 40 HSP children and 25 healthy controls. The percentages of Tfh and Tfr cells were measured by flow cytometry; the mRNA expression levels of Bcl-6, c-MAF, Blimp-1, and PD-1 in peripheral blood were measured by real-time polymerase chain reaction.

RESULTSCompared with the controls, the children with HSP had significantly increased percentage of Tfh cells and Tfh/Tfr ratio but a significantly reduced percentage of Tfr cells in the peripheral blood (P<0.05). Compared with the controls, the children with HSP had significantly increased mRNA expression of Bcl-6 and c-MAF but significantly reduced mRNA expression of Blimp-1 in CD4+ T cells (P<0.05), and had significantly increased mRNA expression of PD-1 but significantly reduced mRNA expression of Blimp-1 in CD4+CD25+ regulatory T cells (P<0.05).

CONCLUSIONSAbnormal percentages of Tfh and Tfr cells may be involved in the pathogenesis of HSP in children, and over-expression of Bcl-6, c-MAF, and PD-1 mRNA and inhibited expression of Blimp-1 mRNA may be considered as important reasons for abnormal percentages of Tfh and Tfr cells.

Adolescent ; Child ; DNA-Binding Proteins ; genetics ; Female ; Humans ; Male ; Programmed Cell Death 1 Receptor ; genetics ; Proto-Oncogene Proteins c-bcl-6 ; Proto-Oncogene Proteins c-maf ; genetics ; Purpura, Schoenlein-Henoch ; etiology ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology ; T-Lymphocytes, Regulatory ; immunology

OBJECTIVETo study the alterations of follicular T helper cells (CD4(+)CXCR5(+)Tfh cells, Tfh) on circulating T lymphocytes in children with asthma, and to study the expression of transcription regulatory factors BCL-6 and BLIMP-1 mRNA.

METHODSSixty-four children with asthma and 25 healthy controls were enrolled in this study. On the basis of the disease, the children with asthma were classified into acute phase group (n=36) and remission phase group (n=28). The flow cytometry was used to detect the proportion of CD4(+)CXCR5(+)Tfh cells on CD4(+)T lymphocytes. Real-time PCR was performed to detect the levels of BCL-6 mRNA and BLIMP-1 mRNA. The double -antibody Sandwich ELISA was used to detect plasma concentrations of total IgE, IL-2, IL-6 and IL-21.

RESULTSThe proportion of CD4(+)CXCR5(+)Tfh cells was significantly higher in the acute group than in the control group and the remission group (P<0.05). Transcription levels of BCL-6 mRNA were significantly higher, while the inhibitory factors BLIMP-1 mRNA was significantly lower in the acute group than in the remission group and control group (P<0.05). The plasma concentration of IL-6 in the acute group increased significantly compared with the control group (P<0.05). Plasma concentrations of total IgE and IL-21 increased significantly, in contrast, plasma IL-2 concentration decreased significantly in the acute group, compared with the control group and the remission group (P<0.05). Correlation analysis showed that both IL-21 and IL-6 concentrations were positively correlated with the proportion of CD4(+)CXCR5(+)Tfh cells (r=0.76, r=0.46 respectively; P<0.05), while IL-2 level was negatively correlated with the proportion of Tfh cells (r=-0.68, P<0.05).

CONCLUSIONSThe abnormal proportion of CD4(+)CXCR5(+)Tfh cells might be involved in the immunological pathogenesis of acute asthma in children. The increased expression of BCL-6 mRNA and decreased expression of BLIMP-1 mRNA as well as the alterations of plasma total IgE, cytokines IL-2, IL-6 and IL-21 in microenvironment might be account for the increased proportion of CD4(+)CXCR5(+)Tfh cells in children with acute asthma.

Asthma ; immunology ; Child ; Child, Preschool ; DNA-Binding Proteins ; genetics ; Female ; Humans ; Immunoglobulin E ; blood ; Infant ; Interleukins ; blood ; Male ; Positive Regulatory Domain I-Binding Factor 1 ; Proto-Oncogene Proteins c-bcl-6 ; RNA, Messenger ; analysis ; Receptors, CXCR5 ; analysis ; Repressor Proteins ; genetics ; T-Lymphocytes, Helper-Inducer ; immunology

OBJECTIVETo study the expression of ecotropic viral integration site (EVI1) gene in childhood acute myeloid leukemia (AML) and the clinical features of EVI1-positive children with AML.

METHODSThe clinical data of EVI1-positive children with AML were collected and analyzed. RT-PCR and real-time quantitative PCR were used for qualitative and quantitative analysis of expression of EVI1. Flow cytometry (FCM) was used for determining the immunophenotypes of bone marrow cells. Multiparameter FCM was used for monitoring minimal residual disease. The karyotypes were determined.

RESULTSOf 241 children with AML, 33 (13.7%) were positive for EVI1 expression. There were no significant differences in age at first visit as well as the white blood cell count, hemoglobin level, and platelet count in peripheral blood between EVI1-positive and EVI1-negative children with AML (P>0.05), but EVI1-positive children had a significantly increased proportion of females compared with EVI1-negative children (P<0.05). The change in EVI1 expression was not synchronous with clinical remission and the change of MRD: some children had clinical remission or negative conversion of MRD before negative conversion of EVI1, while some had negative conversion of EVI1 before clinical remission or while MRD showed positive. EVI1 gene was usually co-expressed with other fusion genes. CD33 (100%), CD38 (88%), and HLADR (76%) were highly expressed in EVI1-positive children with AML. Abnormal chromosome structure or number was found in 15 patients. Compared with EVI1-negative children, EVI1-positive children had significantly lower complete remission rates after the first course of treatment (P<0.05).

CONCLUSIONSEVI1-positive children with AML have a poor short-term prognosis. In the development of AML, the activation of EVI1 gene is not isolated, but the result of interactions with other genes or chromosome abnormalities, and the mechanism of activation and its function need further study.

Adolescent ; Child ; Child, Preschool ; Chromosome Aberrations ; DNA-Binding Proteins ; genetics ; Female ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; Humans ; Immunophenotyping ; Infant ; Leukemia, Myeloid, Acute ; genetics ; immunology ; MDS1 and EVI1 Complex Locus Protein ; Male ; Neoplasm, Residual ; Prognosis ; Proto-Oncogenes ; genetics ; Transcription Factors ; genetics

OBJECTIVETo investigate the clinical value of serum anti-Ku86 in early detection of hepatocellular carcinoma (HCC).

METHODSExpression levels of Ku86 protein in HCC and adjacent normal liver tissues were detected by Western blotting. Serum anti-Ku86 level in 83 patients with early HCC and 124 patients with liver cirrhosis were detected by enzyme-linked immunosorbent assay (ELISA). Chemiluminescence was used to measure the serum level of α-fetoprotein (AFP).

RESULTSExpression of Ku86 protein in HCC was increased when compared with the adjacent normal liver tissues (0.21 ± 0.05 vs. 0.08 ± 0.02, P < 0.01). Serum anti-Ku86 level was significantly elevated in HCC patients compared with that in liver cirrhosis patients (0.47 ± 0.22 vs. 0.22 ± 0.06 Abs at 450 nm, P < 0.01), but there was no significant difference between HBV infection and HCV infection in HCC patients (0.51 ± 0.19 vs. 0.47 ± 0.24, P = 0.267). Of note, serum anti-Ku86 level was significantly decreased after surgical resection of the tumors in the 30 HCC cases tested (P < 0.01). The results of ROC analysis indicated a better performance of anti-Ku86 (0.857) than AFP (0.739) for early detection of HCC. In 83 HCC patients, the positive rate of anti-Ku86 was 61.4% (51/83), significantly higher than that of the AFP positive rate (27.7%, 23/83). The anti-Ku86 level was positive in 37 of 60 HCC cases with negative AFP. Combination assay of AFP and anti-Ku86 could detect 60 of 83 HCC cases (72.3%, 60/83). There was no significant correlation of anti-Ku86 and AFP (r = 0.156, P = 0.161).

CONCLUSIONSSerum anti-Ku86 level is significantly elevated and is not related to HBV and HCV infection in HCC patients. Serum anti-Ku86 antibody may be a potential biomarker for early detection of HCC, and can be used in combination with AFP in clinics.

Adult ; Aged ; Antigens, Nuclear ; immunology ; Autoantibodies ; blood ; Biomarkers, Tumor ; blood ; Carcinoma, Hepatocellular ; blood ; diagnosis ; virology ; DNA-Binding Proteins ; immunology ; Early Detection of Cancer ; Female ; Hepatitis B ; blood ; Hepatitis C ; blood ; Humans ; Ku Autoantigen ; Liver Cirrhosis ; blood ; Liver Neoplasms ; blood ; diagnosis ; virology ; Male ; Middle Aged ; ROC Curve ; alpha-Fetoproteins ; metabolism

OBJECTIVEOmenn syndrome is a rare autosomal recessive hereditary severe combined immunodeficiency. The purpose of this study was to understand clinical characteristics and genetic mutation type of Omenn syndrome and to improve the recognition of Omenn syndrome among pediatric clinicians.

METHODOne suspected case of severe combined immunodeficiency was found to have pneumonia repeatedly, intractable diarrhea, poor antibiotic treatment effect, lymphadenopathy, hepatosplenomegaly and erythroderma. The patient was diagnosed as having Omenn syndrome by RT-PCR, and the expression of RAG1/RAG2 and gene analysis of RAG1/RAG2 were performed.

RESULTThe classification of lymphocyte was CD3(+) cells (35.3%), CD19(+) cells (0.4%), CD16(+) cells (57.6%). After stimulation with phytohemagglutinin (PHA), lymphocyte proliferation of the child was extremely low. Genetic studies showed RAG1 homozygous deletion mutation (2302 del T). He had detectable activated T-lymphocytes with low circulating B-lymphocytes and no evidence of maternal T-cell engrafment as indicated by the short tandem repeat (STR) analysis.

CONCLUSIONOmenn syndrome is a severe combined immunodeficiency disease caused by mutations in the RAG1/RAG2 gene. The disease has been reported rarely in China. The clinical manifestations of the disease is early postnatal repeated infections and erythroderma. Mutation analysis of RAG1/RAG2 gene may help to confirm the diagnosis and may be useful in early immune reconstitution and genetic counseling.

Amino Acid Sequence ; Biomarkers ; blood ; DNA Mutational Analysis ; DNA-Binding Proteins ; genetics ; Genotype ; Homeodomain Proteins ; genetics ; Humans ; Infant ; Lymphocytes ; immunology ; pathology ; Male ; Microsatellite Repeats ; Mutation ; Nuclear Proteins ; genetics ; Phenotype ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Severe Combined Immunodeficiency ; diagnosis ; genetics ; pathology

OBJECTIVETo perform immunophenotyping and molecular genetic analysis for diffuse large B-cell lymphoma (DLBCL), and to explore their correlation and implication for prognosis.

METHODSImmunohistochemical streptavidin peroxidase (SP) method was used to determine the expression of CD10, BCL6 and MUM1 in 59 cases of DLBCL. A Hans algorithm was used to classify DLBCL into germinal center B-cell (GCB) and non-GCB subtypes. Interphase fluorescence in situ hybridization (FISH) assay was performed on paraffin-embedded lymphoma tissue sections to detect translocations and amplifications of BCL6, BCL2 and MYC genes with dual-color break-apart BCL6 probe, dual-color dual-fusion IgH/ BCL2 probe and dual-color break-apart MYC probe, respectively.

RESULTSIn the 59 cases of DLBCL, 28.8% (17/59) belonged to GCB subtype, and 71.2% (42/59) belonged to non-GCB subtype. The incidences of BCL6, BCL2 and MYC gene translocations were 24.1% (14/58), 1.7% (1/59) and 5.3% (3/57), respectively. The incidences of BCL6, BCL2 and MYC gene amplifications were 17.2% (10/58), 22.0% (13/59) and 21.1% (12/57), respectively. BCL6 amplification was not correlated with BCL6 translocation (P=0.424), but was correlated with amplifications of BCL2 and MYC (C=0.405 and 0.403, respectively, P <0.01). The incidence of BCL6 translocation in GCB type was higher than that in non-GCB type, and amplifications of BCL6, BCL2 or MYC were more frequently encountered in non-GCB type, though no statistical significance was detected (P=0.089 and 0.106, respectively). By univariate analysis, immunophenotyping and international prognostic index (IPI) exerted a significant effect on overall survival (OS) (P=0.047 and 0.001, respectively), but to which BCL6 translocation and amplification of the 3 genes were not related (P=0.150 and 0.444, respectively). By multivariate analysis, IPI score was the only independent prognostic factor for OS (RR =3.843, P=0.017).

CONCLUSIONThe GCB subtype of DLBCL is less common in the patient cohort. Common genetic aberrations have included BCL6 translocation and BCL6, BCL2 and MYC amplifications. Amplification of the 3 genes is strongly correlated with each other, and the incidence of BCL2 translocation is low. Immunophenotyping only has minor significance for the prognosis. Genetic aberrations cannot predict the clinical outcome of DLBCL.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; DNA-Binding Proteins ; genetics ; Female ; Genes, bcl-2 ; Genes, myc ; Humans ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Lymphoma, Large B-Cell, Diffuse ; genetics ; immunology ; Male ; Middle Aged ; Proto-Oncogene Proteins c-bcl-6

Graft-versus-host disease (GVHD) is a prevalent and potential complication of hematopoietic stem cell transplantation. An animal model, xenogeneic GVHD (X-GVHD), that mimics accurately the clinical presentation of GVHD would provide a tool for investigating the mechanism involved in disease pathogenesis. Murine models indicated that inhibiting IL-21 signaling was a good therapy to reduce GVHD by impairing T cell functions. We sought to investigate the effect of exogenous human IL-21 on the process of X-GVHD. In this study, human IL-21 was expressed by hydrodynamic gene delivery in BALB/c-Rag2⁻/⁻ IL-2RΓc⁻/⁻ (BRG) immunodeficient mice which were intravenously transplanted human peripheral blood mononuclear cells (hPBMCs). We found that human IL-21 exacerbated X-GVHD and resulted in rapid fatality. As early as 6 days after hPBMCs transplanted to BRG mice, a marked expansion of human CD19⁺ B cells, but not T cells, was observed in spleen of IL-21-treated mice. Compared with control group, IL-21 induced robust immunoglobulin secretion, which was accompanied by increased accumulation of CD19⁺ CD38(high) plasma cells in spleen. In addition, we demonstrated that B-cell depletion was able to ameliorate X-GVHD. These results are the first to find in vivo expansion and differentiation of human B cells in response to IL-21, and reveal a correlation between the expansion of B cells and the exacerbation of xenogeneic GVHD. Our findings show evidence of the involvement of B cells in X-GVHD and may have implications in the treatment of the disease.
Animals ; B-Lymphocytes ; immunology ; metabolism ; pathology ; Cell Differentiation ; Cell Proliferation ; DNA-Binding Proteins ; deficiency ; Female ; Graft vs Host Disease ; blood ; genetics ; immunology ; metabolism ; Heterografts ; immunology ; Humans ; Immunoglobulin G ; metabolism ; Immunoglobulin M ; metabolism ; Interleukins ; genetics ; immunology ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics