The inflammasome is a multi-protein complex that induces maturation of inflammatory cytokines interleukin (IL)-1beta and IL-18 through activation of caspase-1. Several nucleotide binding oligomerization domain-like receptor family members, including NLRP3, recognize unique microbial and danger components and play a central role in inflammasome activation. The NLRP3 inflammasome is critical for maintenance of homeostasis against pathogenic infections. However, inflammasome activation acts as a double-edged sword for various bacterial infections. When the IL-1 family of cytokines is secreted excessively, they cause tissue damage and extensive inflammatory responses that are potentially hazardous for the host. Emerging evidence has shown that diverse bacterial pathogens or their components negatively regulate inflammasome activation to escape the immune response. In this review, we discuss the current knowledge of the roles and regulation of the NLRP3 inflammasome during bacterial infections. Activation and regulation of the NLRP3 inflammasome should be tightly controlled to prevent virulence and pathology during infections. Understanding the roles and regulatory mechanisms of the NLRP3 inflammasome is essential for developing potential treatment approaches against pathogenic infections.
Bacterial Infections/immunology/metabolism/pathology/prevention & control ; Carrier Proteins/*metabolism ; Caspase 1/metabolism ; Humans ; Inflammasomes/immunology/*metabolism ; Interleukin-1beta/metabolism ; Signal Transduction

Carrier Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Gene Library ; Hepatitis B Surface Antigens ; immunology ; metabolism ; Hepatitis B virus ; genetics ; immunology ; Humans ; Immunoprecipitation ; Intracellular Signaling Peptides and Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Viral Proteins ; immunology ; metabolism

In recent years, the potential value of nonstructural protein (NSP) 2C was well documented for distinguishing foot-and-mouth disease virus (FMDV) in infected animals and vaccinated animals. In order to develop a more sensitive approach to detect natural infected FMDV while there is no interact with vaccinated FMDV, we incorporated a major epitope region of 2C with whole 3AB coding region within NSP and expressed in Escherichia coli. We got a 47.6 kD fusion protein named 2C'3AB. The product showed a specific reactivity with FMDV from serum of infected animal by using Western blotting analysis. This suggests that this protein could be applied to distinguish infected FMDV and vaccinated FMDV. We further compared 2C'3AB protein with 3ABC fusion protein, another available protein used for detecting infected FMDV, using indirect ELISA assay. The results showed that 2C'3AB-ELISA had higher sensitivity than that of 3ABC-ELISA for distinguishing infected FMDV and vaccinated FMDV of sera from epidemic region. Therefore, this recombinant protein 2C'3AB is a good candidate protein to develop more sensitive method to differentiate infected FMDV and vaccinated FMDV from vaccinated animals. This finding will increase our capability to check the infectious virus carrier and finally improve FMDV infection control.
Animals ; Antibody Specificity ; Carrier Proteins ; genetics ; immunology ; metabolism ; Epitopes ; immunology ; Escherichia coli ; genetics ; metabolism ; Foot-and-Mouth Disease Virus ; genetics ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism ; Viral Nonstructural Proteins ; genetics ; immunology ; metabolism

Nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) are pattern-recognition receptors similar to toll-like receptors (TLRs). While TLRs are transmembrane receptors, NLRs are cytoplasmic receptors that play a crucial role in the innate immune response by recognizing pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Based on their N-terminal domain, NLRs are divided into four subfamilies: NLRA, NLRB, NLRC, and NLRP. NLRs can also be divided into four broad functional categories: inflammasome assembly, signaling transduction, transcription activation, and autophagy. In addition to recognizing PAMPs and DAMPs, NLRs act as a key regulator of apoptosis and early development. Therefore, there are significant associations between NLRs and various diseases related to infection and immunity. NLR studies have recently begun to unveil the roles of NLRs in diseases such as gout, cryopyrin-associated periodic fever syndromes, and Crohn's disease. As these new associations between NRLs and diseases may improve our understanding of disease pathogenesis and lead to new approaches for the prevention and treatment of such diseases, NLRs are becoming increasingly relevant to clinicians. In this review, we provide a concise overview of NLRs and their role in infection, immunity, and disease, particularly from clinical perspectives.
Autophagy/immunology ; Carrier Proteins ; Humans ; *Immunity, Innate ; Inflammasomes ; Nod Signaling Adaptor Proteins/immunology/*metabolism ; Pathogen-Associated Molecular Pattern Molecules ; Receptors, Cytoplasmic and Nuclear/immunology/*metabolism ; Receptors, Pattern Recognition/*immunology ; *Signal Transduction ; Toll-Like Receptors/metabolism

OBJECTIVETo explore the regulatory effects of hTERT and TEP1 on telomerase activity in hematopoiesis.

METHODSThe hTERT and TEP1 mRNA expression was detected by RT-PCR and the telomerase activi-ty by TRAP.

RESULTSIn mononuclear cells (MNC) and CD(34)(-) cells, no detectable telomerase activity and hTERT mRNA expression were found. CD(34)(+) cells showed hTERT expression and a low level telomerase activity. TEP1 mRNA was detected in MNC, CD(34)(-) and CD(34)(+) cells with no significant difference in the expression level. In the CD(34)(+) cells cultured in vitro with growth factors for 7 days, the telomerase activity and the expression of hTERT mRNA were upregulated, but were downregulated in the long time culture. No significant changes in TEP1 expression was observed.

CONCLUSIONIn the course of hematopoiesis, hTERT mRNA expression was in accordance with telomerase activity, hTERT gene plays a crucial role in the expression of telomerase activity, while TEP1 gene plays, if any, a much smaller role.

Antigens, CD34 ; immunology ; Carrier Proteins ; genetics ; DNA-Binding Proteins ; Fetal Blood ; cytology ; metabolism ; Gene Expression ; Humans ; Leukocytes, Mononuclear ; cytology ; immunology ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells ; cytology ; metabolism ; Telomerase ; genetics

OBJECTIVETo elucidate the expression and function of VAP-33 gene in dendritic cell sarcoma (DCS) cell line.

METHODSThe expression of VAP-33 in DCS cells was investigated by mass spectrum with immunoprecipitation membrane protein. DCS cells were treated with antigens in different dosages (150, 850, and 1500 microl) for 24, 48 and 72 h respectively. Cell morphology and phagocytosis activity of DCS cells were measured. Indirect immunofluorescence, confocal microscopy and Western blotting were used to study the distribution and expression changes of VAP-33. Moreover, DCS cells were treated with 0.5 mol/L insulin for 20 min first and followed by Western blotting to detect changes of VAP-33 and glucose transfer protein 4 (GLUT-4) in the total cellular protein, cytoplasmic protein and membrane protein. Confocal microscopy was used to document the expression and distribution changes of VAP-33 and GLUT-4 in DCS cells.

RESULTSVAP-33 expression was obtained at the cell membrane and in the cytoplasm of DCS cells. Upon antigen stimulation, DCS cells showed more active phagocytosis and morphologically became more elongated with branched protrusions. The expression of VAP-33 was decreased by the antigen stimulation. Upon the insulin stimulation, the expression of VAP-33 and GLUT-4 were increased and co-localized.

CONCLUSIONSVAP-33 expression in DCS originated from the dendritic cells (DC) seemed relating to the vesicle transportation during antigen processing in DC. Additionally, VAP-33 and GLUT-4 also take part in the glucose transportation in the cells.

Animals ; Antigen Presentation ; Carrier Proteins ; metabolism ; Cell Line, Tumor ; Cell Membrane ; metabolism ; Cytoplasm ; metabolism ; Dendritic Cell Sarcoma, Interdigitating ; metabolism ; pathology ; Down-Regulation ; Glucose Transporter Type 4 ; metabolism ; Insulin ; pharmacology ; Membrane Proteins ; metabolism ; Mice ; Phagocytosis ; immunology

Inflammasomes are multiprotein complexes that serve as a platform for caspase-1 activation and interleukin-1β (IL-1β) maturation as well as pyroptosis. Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied. NLRP3 inflammasome is triggered by a variety of stimuli, including infection, tissue damage and metabolic dysregulation, and then activated through an integrated cellular signal. Many regulatory mechanisms have been identified to attenuate NLRP3 inflammasome signaling at multiple steps. Here, we review the developments in the negative regulation of NLRP3 inflammasome that protect host from inflammatory damage.
Animals ; Autophagy ; Carrier Proteins ; antagonists & inhibitors ; metabolism ; Caspase 1 ; metabolism ; Humans ; Inflammasomes ; metabolism ; Interferon Type I ; metabolism ; MicroRNAs ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Nitric Oxide ; metabolism ; Signal Transduction ; T-Lymphocytes ; immunology ; metabolism

OBJECTIVETo determine the immunoprotective effects of rUreB and rHpaA bivalence genetic engineering vaccine with inner adjuvant of rLTB on BALB/c mice against H.pylori strain SS1 infection.

METHODSrUreB, rHpaA, rLTB-rUreB-rHpaA, rLTKA63, rLTB and rLTB were collected by NTA-Ni affinity chromatography. Western blot was applied to demonstrate the immunoreactivity of the recombinant protein antigens. Adjuvant activities of rLTB, rCTB and rLTB-rUreB-rHpaA were determined by GM1-ELISA. H.pylori strain SS1-infected BALB/c mouse modal was established to measure immunoprotective effects of different compositions of antigens and adjuvants. H.pylori in gastric biopsy specimens was examined by routine isolation method and silver staining method. Two ELISAs were established to detect specific S-IgA in gastric juices and specific IgA in sera of the immunized mice.

RESULTSrUreB, rHpaA and rLTB-rUreB-rHpaA were recognized by commercial antibody against whole cell of H.pylori and were able to combine to the bovine GM1. The protective rate in the mice immunized with single rUreB or rHpaA was lower than 70%. When using rUreB or rHpaA plus rLTB or rCTB, the positive rates increased to 75.0%-83.3%. With different combination of antigens and adjuvants, the immunoprotective rate of rLTB-jrUreB-rHpaA was as high as 100%, and then was 91.7% for rUreB+rHpaA+rCTB+rLTKA63 and was 90.9% for rUreB+rHpaA+rLTB. Both the rLTB and rCTB showed remarkable effects to induce specific IgA in sera and specific S-IgA in gastric juices of the immunized mice, and the former showed stronger S-IgA-inducing ability than the latter. The positive rates of specific IgA were basically identical to the corresponding mouse immunoprotective rates. S-IgA positive rates specific to rUreB and rHpaA in rLTB-rUreB-rHpaA immunized mice were 100% and 91.7%, respectively.

CONCLUSIONThe rUreB and rHpaA possess qualified immunoreactivity and antigenicity. The rLTB and rCTB can show adjuvant activity of mucosal immunization. The high immunoprotective rate of Helicobacter pylori UreB and HpaA bivalence recombinant vaccine with inner adjuvant in mice is associated with high dosage of rLTB, larger molecular weight of the antigen and the high levels of local specific S-IgA.

Adjuvants, Immunologic ; biosynthesis ; genetics ; Animals ; Bacterial Proteins ; biosynthesis ; genetics ; immunology ; Bacterial Vaccines ; immunology ; Carrier Proteins ; biosynthesis ; genetics ; immunology ; Female ; Genetic Engineering ; Helicobacter Infections ; prevention & control ; Helicobacter pylori ; immunology ; Immunoglobulin A ; blood ; metabolism ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Vaccines, Synthetic ; immunology

Animals ; Carrier Proteins ; metabolism ; Caspase 1 ; metabolism ; Humans ; Inflammasomes ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; toxicity ; Mice ; Monocytes ; drug effects ; immunology ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Signal Transduction ; drug effects

Genetic transformation was adopted to analyze the subcellular localization and the resistance to fungal pathogens of Arabidopsis lipid transfer protein AtDHyPRP1. The coding sequence of AtDHyPRP1 amplified by PCR from Ws ecotype was used to construct the plant binary expression vector pRI101-AN-AtDHyPRP1 and the fusion expression vector pCAMBIA1302-AtDHyPRP1-GFP. Transgenic tobacco and Arabidopsis plants were produced by leaf disc and floral dip protocols, respectively. AtDHyPRP1 could improve the resistance of tobacco to Botrytis cinerea remarkably and the infection sites on transgenic tobacco leaves accumulated large amounts of H2O2. Observation under laser scanning confocal microscope showed that AtDHyPRP1 was localized to cell surface. It suggested that AtDHyPRP1 might play special function after secretion to outside of the cell and was involved in plant defense system against pathogens.
Amino Acid Sequence ; Antigens, Plant ; genetics ; metabolism ; Arabidopsis ; genetics ; metabolism ; microbiology ; Arabidopsis Proteins ; genetics ; metabolism ; Botrytis ; Carrier Proteins ; genetics ; metabolism ; Disease Resistance ; Escherichia coli ; genetics ; metabolism ; Molecular Sequence Data ; Plant Diseases ; immunology ; microbiology ; Plant Proteins ; genetics ; metabolism ; Plants, Genetically Modified ; genetics ; metabolism ; microbiology ; Recombinant Proteins ; genetics ; metabolism ; Subcellular Fractions ; metabolism ; Tobacco ; genetics ; metabolism ; microbiology