The motile marine bacterium, Vibrio vulnificus has a total of six flagellins. Flagellin is a structural component of flagellar filament in various locomotive bacteria and is the ligand of Toll-like receptor 5 (TLR5). TLRs, highly expressed on various types of cells including dendritic cells (DCs), recognize invading microorganisms and finally trigger host immune responses. In this study, we prepared all of six recombinant flagellin proteins and assessed the effect of six flagellins on IL-8 activation through TLR5 recognition. Although showed different activities, five out of the six flagellins stimulated significant IL-8 activation. We also investigated the immunomodulatory roles of Vv-FlaB, the crucial building block of V. vulnificus flagellar filament, on human dendritic cells. Treatment of immature DCs with Vv-FlaB resulted in an increased expression of co-stimulatory molecules and induced strong allo-T cell proliferative activities of the DCs. These results show that the Vv-FlaB may serve an epochal immune adjuvant possessing effective immunomodulatory activities.
Bacteria ; Dendritic Cells* ; Flagellin* ; Flow Cytometry ; Humans* ; Interleukin-8 ; Toll-Like Receptor 5 ; Vibrio vulnificus* ; Vibrio*

OBJECTIVETo study the significance of toll-like receptors (TLR) -7 and -8 in the pathogenesis of infection caused by Enterovirus type 71 (EV71) through measuring the expression of TLR7 and TLR8 in brain and lung tissues from the death cases caused by EV71 infection.

METHODSNine children who died of EV71 infection (EV71 group) were selected as study subjects, and 7 children who died of accidents or non-infectious diseases were used as the control group. Brain and lung tissues from the death cases in both groups at autopsy were collected, and immunohistochemistry was applied to detect the expression of TLR7 and TLR8 in lung and brain tissues in both groups. Integrated optical density (IOD) was applied for semi-quantitative analysis of the expression of TLR7 and TLR8.

RESULTSImmunohistochemical results showed that the expression of TLR7 and TLR8 in lung and brain tissues was strongly positive in the EV71 group, and the IOD values in the EV71 group were also significantly higher than those in the control group (P<0.05). There was no significant difference in the expression of TLR7 and TLR8 between lung and brain tissues in the EV71 group (P>0.05).

CONCLUSIONSTLR7 and TLR8 are highly expressed in lung and brain tissues from the patients who die of severe EV71 infection, suggesting that TLR7 and TLR8 may be involved in the pathogenesis of brain and lung damages caused by severe EV71 infection.

Brain ; immunology ; Child ; Cytokines ; physiology ; Enterovirus A, Human ; Enterovirus Infections ; etiology ; immunology ; Humans ; Lung ; immunology ; Toll-Like Receptor 7 ; analysis ; physiology ; Toll-Like Receptor 8 ; analysis ; physiology

OBJECTIVETo investigate whether Candida albicans-native phospholipomannan (PLM) induce an inflammation response through Toll-like receptor(TLRé2 in human acute monocytic leukemia cell line (THP-1) cells.

METHODSHuman THP-1 monocytes were challenged with PLM in vitro. The mRNA expressions of TLR2, TLR4, proinflammatory cytokine [interleukin(IL)-6], and chemokine (IL-8) were assayed by real time reverse transcription polymerase chain reaction. The secretions of IL-6 and IL-8 were measured by enzyme-linked immunosorbent assay. The expression of TLR2 was analyzed with Western blot.

RESULTSPLM increased the mRNA expressions and secretions of proinflammatory cytokines (IL-6) and chemokines (IL-8) in THP-1 cells (all P=0.0000). PLM up-regulated the mRNA and protein levels of TLR2 (P=0.0000), whereas the mRNA level of TLR4 was not altered. PLM hydrolyzed with β-D-mannoside manno hydrolase failed to induce gene and protein expressions of TLR2, IL-6, and IL-8. Anti-TLRS-neutralizing antibody blocked the PLM-induced secretions of IL-6 and IL-8 in THP-1 cells (P = 0.0003, P = 0.0010).

CONCLUSIONCanidada albicans-native PLM may contribute to the inflammatory responses during Candida infection in a TLR2-dependent manner.

Candida albicans ; chemistry ; Cells, Cultured ; Glycolipids ; pharmacology ; Humans ; Interleukin-6 ; metabolism ; Interleukin-8 ; metabolism ; Monocytes ; drug effects ; immunology ; metabolism ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism

BACKGROUNDCornea epithelial cells play early and crucial roles in the initiation of ocular surface responses to pathogens. Participation of toll-like receptor (TLR) 2 and TLR4, which are major forms of fungi receptors, may be involved in Aspergillus fumigatus induced immune responses. The objective of the present study was to examine whether inactive Aspergillus fumigatus conidia induce NF-kappaB activation and production of proinflammatory cytokines, and whether the expression of TLR2 and TLR4 were amplified by conidia in cultured immortalized human corneal epithelial cells (THCEs). This may contribute to our knowledge of the mechanism by which the host cornea can successfully defend against invasive fungi.

METHODSAspergillus fumigatus conidia were used to challenge THCE cells. THCE cells were harvested after 0.5, 1, 2 or 4 hours incubation. Real-time quantitative PCR was performed to determine the expression of TLR2, TLR4, TNF-alpha and IL-8. Western blotting was performed to determine the expression of NF-kappaB. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the expression of TNF-alpha and IL-8. And the release of TNF-alpha and IL-8 in the cell supernatant were also assessed by ELISA with or without pretreatment with TLR2 and TLR4 neutralizing antibodies.

RESULTSAspergillus fumigatus conidia elicited the expression of TLR2, TLR4, TNF-alpha and IL-8 mRNA in THCEs. Exposure of THCE cells to Aspergillus fumigatus conidia resulted in NF-kappaB activation, which increased at 30 minutes (increased from 11.35+/-2.74 in the controls to 19.12+/-3.48, P<0.05) and thereafter increased steadily up to 4 hours after challenge (P<0.01). Concomitant with NF-kappaB activation, secretion of TNF-alpha and IL-8 in conidia-challenged cells was increased in a time-dependent manner. Incubation of THCE cells with TLR2 antibody or TLR4 antibody before conidia challenge resulted in inhibition of conidia-induced TNF-alpha and IL-8 secretion (P<0.05), TLR2 antibody and TLR4 antibody together significantly increased inhibition of the conidia-induced secretion of TNF-alpha and IL-8 from THCE cells (P<0.01).

CONCLUSIONAspergillus fumigatus conidia stimulates THCEs inflammatory response through a pathway dependent on TLR2 and TLR4 signaling.

Aspergillus fumigatus ; immunology ; Cells, Cultured ; Epithelium, Corneal ; cytology ; immunology ; Humans ; Interleukin-8 ; biosynthesis ; NF-kappa B ; metabolism ; Toll-Like Receptor 2 ; physiology ; Toll-Like Receptor 4 ; physiology ; Tumor Necrosis Factor-alpha ; biosynthesis

This study is to evaluate the role of TLR-4 in lower laminar shear stress-induced interleukin-8 gene transcription activation in vascular endothelial cells by using gene mutation and transfection techniques. RT-PCR, Northern hybridization and immunocytochemical fluorescent staining showed that TLR-4 was expressed in human umbilical vein endothelial cells(HUVEC). When stimulated with 4.2 dyne/cm2 shear stress for 1 hour, an increase of TLR-4 mRNA expression was observed in HUVECs detected by RT-PCR and Northern hybridization. The intracellular domain deletion mutant TLR-4 cDNA (lacking the 155 COOH terminal amino acids of the wild type (TLR-4) and -102 -61 bp DNA sequence in 5'-flanking region of IL-8 gene (IL-8USCS) were isolated from endothelial cells by RT-PCR and PCR. These two DNA fragments were cloned into pcDNA3 and pEGFP1 respectively to construct TLR-4 dominant negative mutant pcDNA3-mTLR4 and IL-8 reporter gene pEGFP1-IL8USCS. ECV304 cells were transfected with the pEGFP1-IL8USCS or co-transfected with pEGFP1-IL8USCS and pcDNA3-mTLR4 by Dosper liposome transfectional reagent and selected by G418, then stimulated with 4.2 dyne/cm2 shear stress for 3 hours. Flow cytometric analysis showed that when exposed to 4.2 dyne/cm2 shear stress for 3 hours, there was a marked increase in the green fluorescent protein expression in pEGFP1-IL8USCS-transfected ECV304 cells. In contrast, there was almost no change in the green fluorescent protein expression in the cells co-transfected with pEGFP1-IL8USCS and pcDNA3-mTLR4 after the stimulation, suggesting the TLR-4 mutant depressed TLR-4 signaling. These experiments suggest that the inflammatory TLR-4/NF-kappa B signaling pathway would probably be involved in flow shear stress-induced IL-8 gene expression in human vascular endothelial cells.
Cells, Cultured ; Endothelium, Vascular ; cytology ; physiology ; Gene Expression Regulation ; Humans ; Interleukin-8 ; genetics ; Membrane Glycoproteins ; genetics ; physiology ; Mutation ; Receptors, Cell Surface ; genetics ; physiology ; Stress, Mechanical ; Toll-Like Receptor 4 ; Toll-Like Receptors ; Transcription, Genetic ; physiology ; Transfection ; Umbilical Veins ; cytology

The aim of study was to explore the potential application of targeting at Toll-like receptors (TLRs) in the immunotherapy of acute myelocytic leukemia, and to investigate the expression of TLR and the effects of TLR 8 agonist ssRNA40/LyoVec on proliferation, apoptosis and cell cycle of U937 cells. The expression of TLR 1 - 9 in U937 cells was detected by using reverse transcription polymerase chain reaction (RT-PCR) and the expression of TLR 8 was assayed by flow cytometry (FCM). The effect of TLR 8 agonist, ssRNA40/LyoVec, at different concentrations on U937 cells proliferation was evaluated by CCK-8, apoptosis and cell cycle were detected by FCM. The results showed that U937 cells expressed TLR 1 - 9. TLR 8 agonist ssRNA40/LyoVec could inhibit the growth of U937 cells both in time-and dose-dependent manner and the inhibitory rate could reach 70%. It also increased the percentage of cells in G(0)/G(1) phase. There was no significant difference in percentage of apoptotic cells between control and treated groups. It is concluded that TLRs including TLR 1 - 9 express on U937 cells and TLR 8 agonist ssRNA40/LyoVec may be able to inhibit the growth of U937 cells, arrest the cells in G(0)/G(1) phase, but have no effect of promoting apoptosis.
Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Reverse Transcriptase Polymerase Chain Reaction ; Toll-Like Receptor 8 ; agonists ; Toll-Like Receptors ; metabolism ; U937 Cells

The etiology of periodontal disease is multifactorial. Exogenous stimuli such as bacterial pathogens can interact with toll-like receptors to activate intracellular calcium signaling in gingival epithelium and other tissues. The triggering of calcium signaling induces the secretion of pro-inflammatory cytokines such as interleukin-8 as part of the inflammatory response; however, the exact mechanism of calcium signaling induced by bacterial toxins when gingival epithelial cells are exposed to pathogens is unclear. Here, we investigate calcium signaling induced by bacteria and expression of inflammatory cytokines in human gingival epithelial cells. We found that peptidoglycan, a constituent of gram-positive bacteria and an agonist of toll-like receptor 2, increases intracellular calcium in a concentration-dependent manner. Peptidoglycan-induced calcium signaling was abolished by treatment with blockers of phospholipase C (U73122), inositol 1,4,5-trisphosphate receptors, indicating the release of calcium from intracellular calcium stores. Peptidoglycan-mediated interleukin-8 expression was blocked by U73122 and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethyl ester). Moreover, interleukin-8 expression was induced by thapsigargin, a selective inhibitor of the sarco/endoplasmic reticulum calcium ATPase, when thapsigargin was treated alone or co-treated with peptidoglycan. These results suggest that the gram-positive bacterial toxin peptidoglycan induces calcium signaling via the phospholipase C/inositol 1,4,5-trisphosphate pathway, and that increased interleukin-8 expression is mediated by intracellular calcium levels in human gingival epithelial cells.
Bacteria ; Bacterial Toxins ; Calcium ; Calcium Signaling* ; Calcium-Transporting ATPases ; Cytokines ; Epithelial Cells ; Epithelium* ; Gram-Positive Bacteria ; Humans ; Inflammation ; Inositol 1,4,5-Trisphosphate Receptors ; Interleukin-8* ; Peptidoglycan* ; Periodontal Diseases ; Phospholipases ; Reticulum ; Thapsigargin ; Toll-Like Receptor 2 ; Toll-Like Receptors ; Type C Phospholipases

OBJECTIVETo observe the effect of Qingchang Huashi Recipe (QHR) on the activation and expressions of nuclear factor kappaB (NF-kappaB), Toll-like receptors (TLRs), and contents of interleukin-8 (IL-8), thus exploring its possible mechanisms for treating ulcerative colitis (UC).

METHODSThe HT-29 cells were induced to inflammation model by tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharides (LPS). HT-29 cells were divided into 6 groups, i.e., the vehicle control group, the model control group, the sulfasalazine (SASP) group, the high dose QHR group, the middle dose QHR group, the low dose QHR group. Effects on the cell growth were detected by MTT. The chemoattractant of macrophages was observed using Transwell. The expressions of NF-kappaB and TLR4 protein were detected using immune cell fluorescence method. The content of IL-8 was detected by ELISA.

RESULTSThe growth of cells were not inhibited in each group. Statistical difference existed in each dose QHR group in inhibiting the chemoattractant of macrophages, reducing activation of NF-kappaB, lowing expressions of TLR4 protein, and decreasing the secretion of IL-8, when compared with the model control group (P < 0.05). No statistical difference existed in inhibiting the chemoattractant of macrophages between the high dose QHR group and the vehicle control group (P > 0.05). But its inhibition on NF-kappaB activation was higher in the high dose QHR group than in the SASP group (P < 0.05).

CONCLUSIONQHR could obviously attenuate the inflammatory reaction of HT-29 cells, inhibit the chemoattractant of macrophages, reduce the activation of NF-kappaB, lower expressions of TLR-4, and attenuate the secretion of IL-8, which might be one of its mechanisms for treating UC.

Colitis, Ulcerative ; metabolism ; pathology ; Drugs, Chinese Herbal ; pharmacology ; HT29 Cells ; Humans ; Inflammation ; Interleukin-8 ; metabolism ; NF-kappa B ; metabolism ; Signal Transduction ; drug effects ; Toll-Like Receptor 4 ; metabolism

OBJECTIVETo examine interleukin-8 (IL-8) mRNA expression induced by flow shear stress in human umbilical vein endothelial cells (HUVECs) and investigate its transcriptional activation.

METHODSFlow laminar shear stress 4.2 dyne/cm(2) was used for the stimulating experiments. The flow shear stress-induced IL-8 mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). pEGFP1 was used to construct IL-8 reporter gene pEGFP1-IL8USCS for determining IL-8 gene transcriptional activation through gene transfer and flow cytometric analysis. NF-kappaB nuclear translocation was observed by immunocytofluorescent staining. Western blot was used to examine IkappaB phosphorylation and degradation. RT-PCR, Northern blot, immunocytofluorescent staining and laser confocal microscopy were used to determine Toll-like receptor-4 (TLR-4) expression at mRNA and protein levels in the cells.

RESULTSThere was a marked increase in IL-8 mRNA expression in HUVECs after 120 min of exposure to laminar flow shear stress. When exposed to shear stress for 180 min, there was an increase in enhanced green fluorescent protein expression in pEGFP1-IL8USCS-transfected endothelial cells. NF-kappaB p65 immunocytofluorescent staining of HUVECs showed that when exposed to the same flow shear stress for 30 or 60 min, the cell nuclei became stained; after 90 or 120 min, the staining became much more pronounced. A significant increase in P-IkappaB in the cell lysates occurred after 10 min of exposure while blot density dramatically dropped after 60 min of exposure. The density of the IkappaB blot dropped with increasing exposure time after 30 min. TLR-4 was present on the surface of HUVECs. HUVECs constitutively expressed TLR-2 and TLR-4 mRNA; when exposed to flow shear stress for 60 min, TLR-4 mRNA expression increased.

CONCLUSIONNF-kappaB activation is involved in flow shear stress-induced IL-8 mRNA expression in human umbilical vein endothelial cells. TLR-4 receptor for innate immunity most likely mediate these events.

Blotting, Northern ; Cells, Cultured ; Drosophila Proteins ; Endothelium, Vascular ; cytology ; metabolism ; Humans ; Interleukin-8 ; genetics ; Membrane Glycoproteins ; analysis ; NF-kappa B ; metabolism ; RNA, Messenger ; analysis ; Receptors, Cell Surface ; analysis ; Stress, Mechanical ; Toll-Like Receptor 2 ; Toll-Like Receptor 4 ; Toll-Like Receptors ; Transcriptional Activation

OBJECTIVETo investigate the effects of Trichophyton rubrum exposure on the expressions of toll-like receptor-2 (TLR-2), TLR-4 and dendritic cell associated C-type lectin-1 (Dectin-1) and cytokine secretions in human keratinocytes cell line HaCaT.

METHODSThe mRNA of TLR-2,4, and dectin-1 in the HaCaT co-cultured with the conidia of Trichophyton rubrum conidia for 24 h was measured with real-time PCR. The mean fluorescence intensity and the percentage of cells positive for TLR-2, 4, and dectin-1 was detected during the co-culture using flow cytometry. The cytokine secretion profiles in the cell culture supernatant was analyzed using a cytokine antibody array.

RESULTSThe TLR-2,4, and dectin-1 mRNA expressions, mean fluorescence intensity and percentage of positive cells for TLR-2,4, and dectin-1 all increased in HaCaT cells in response to Trichophyton rubrum conidia exposure. The results of cytokine antibody array demonstrated obviously increased secretions of IL-8, I-309, IFN-γ, IL-6, and IL-13 in the culture supernatant of HaCaT cells in response to Trichophyton rubrum exposure.

CONCLUSIONThe immune responses and immunological recognition of human keratinocytes to Trichophyton rubrum conidia are partially mediated by up-regulating the expressions of TLR-2, TLR-4 and dectin-1 and secretions of multiple cytokines.

Cell Line ; Chemokine CCL1 ; secretion ; Coculture Techniques ; Humans ; Interferon-gamma ; secretion ; Interleukin-13 ; secretion ; Interleukin-6 ; secretion ; Interleukin-8 ; secretion ; Keratinocytes ; metabolism ; Lectins, C-Type ; metabolism ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism ; Trichophyton ; Tumor Necrosis Factor-alpha ; secretion