Organ transplant has become one of the strategies for treatment of malignant disease. The transplant-related complications restricted the further development of organ transplantation; graft rejection is most prominent among these complications, which remains a major cause of morbidity and mortality after organ transplant. Toll like receptors 4 (TLR-4) has been shown as a key molecule in innate immunity and immune tolerance. The role of TLR4 in graft rejection after organ transplant is still unknown. This article will review the role and the mechanism of TLR4 to control APC mature, activate T cells, trigger immune attack to organ graft; therefore bring new insights into the pathophysiology of graft rejection and foster the development of new therapies to control graft rejection after organ transplant.
Graft Rejection ; immunology ; Humans ; Toll-Like Receptor 4 ; immunology

OBJECTIVETo investigate the effect of RNA interfering TLR4 signal pathway on phagocytosis of Kupffer cells.

METHODSRAW2647 mice mononuclear macrophage leukemia cells were observed. The tested group was interfered by Tlr4-mus-1567 RNA which had the best result confirmed by QPCR, cells interfered by Negative Control RNA as NC group, and normal cell as control. We perform the phagocytosis test on each group.

RESULTSThe tested group has lower phagocytes percentage than control (17.67% +/- 3.51% vs 32.00% +/- 3.00%, P < 0.01), and lower phagocytic index (46.33% +/- 7.51% vs 82.00% +/- 6.08%, P < 0.01).

CONCLUSIONSDecreased phagocytic activity was observed on Kupffer cells by RNA interference.

Animals ; Kupffer Cells ; immunology ; Mice ; Phagocytosis ; RNA Interference ; Signal Transduction ; Toll-Like Receptor 4 ; genetics ; immunology

Infection and antibiotic multidrug resistance have become the focal issue in clinical treatment of acute leukemia and will make anti-infection therapy facing to new challenge. Toll-like receptor (TLR) has been found a newly innate immunoreceptor. It is significant in immune response. Along with further investigation of TLR, infection and anti-infection immunity theory would gain a new breakthrough and play a guiding role in clinical treatment of acute leukemia complicated with infection. In this review, the progress in the research of TLR and its expression in acute leukemia complicated with infection were summarized.
Acute Disease ; Humans ; Infection ; complications ; immunology ; Leukemia ; complications ; immunology ; metabolism ; Toll-Like Receptor 4 ; immunology ; metabolism ; Toll-Like Receptors ; immunology ; metabolism

OBJECTIVETo study the surface antigen of the dendritic cells (DC) and their Toll-like receptor 4 (TLR4) expression in patients with idiopathic thrombocytopenic purpura (ITP), and to explore their role in ITP pathogenesis.

METHODSThe peripheral blood mononuclear cells isolated from complete remission patients (CR), non-complete remission patients (n-CR) and normal controls were stimulated by rhGM-CSF and rhIL-4. The surface antigen of the DC was analyzed by flow cytometry. The level of IL-12p70 in the supernatant was detected by enzyme linked immunosorbent assay. The expression of TLR4 mRNA of DC was detected by real time PCR.

RESULTSIn the 21 CR ITP patients, the expression of both CD80 and CD86 in DC was significantly increased compared with that in normal controls \[(51.60 ± 13.47)% vs (36.03 ± 15.43)%, (61.50 ± 15.93)% vs (40.28 ± 11.49)%, respectively\] (P < 0.01). The expression of CD80 and CD86 in n-CR group was also significantly increased \[(53.29 ± 19.49)% and (62.91 ± 18.43)%, respectively\] (P < 0.01). After HD-DXM treatment, both CD80 and CD86 in CR patients were decreased (P < 0.01). There was no difference between the DXM treatment patients and the normal controls. In n-CR group, there was no difference in CD80 and CD86 expression before and after DXM therapy \[(52.30 ± 20.98% and (49.79 ± 20.28)%, respectively\] (P > 0.05). CD80 was still higher than normal (P < 0.05), while CD86 was not changed. The level of IL-12p70 in CR ITP patients before treatment was significantly higher \[(67.52 ± 14.43) pg/ml\] than that of the controls \[(39.78 ± 10.03) pg/ml\](P < 0.01), and after treatment, was significantly decreased to (43.90 ± 8.49) pg/ml, being no difference from that in control. In n-CR group, IL-12p70 was lower after treatment \[(48.45 ± 9.68) pg/ml\] than that before treatment \[(65.35 ± 12.52) pg/ml\] (P < 0.01), but still higher than that in control (P < 0.05). The TLR4 mRNA level in DCs of CR ITP patients before treatment were significantly higher 0.69 ± 0.17 than that of controls (0.31 ± 0.09) (P < 0.01) and after treatment, was reduced to 0.35 ± 0.11, being no difference from that in control. In n-CR group, TLR4 mRNA was decreased from 0.65 ± 0.09 to 0.52 ± 0.21 after treatment (P < 0.01), but still higher than normal (P < 0.01).

CONCLUSIONDC may play an important role in ITP by their Toll-like receptor and cytokine secretion.

Dendritic Cells ; immunology ; Humans ; Interleukin-12 ; metabolism ; Leukocytes, Mononuclear ; Purpura, Thrombocytopenic, Idiopathic ; immunology ; Toll-Like Receptor 4

OBJECTIVE: To explore the role of the innate immune factors TLR2 and TLR4 in the pathogenesis of chronic rhinosinusitis (CRS) by detecting their expression in different clinical types of CRS and the normal control group. METHOD: Immunohistochemistry was used to detect the expression of TLR2 and TLR4 respectively in 21 cases (chronic rhinosinusitis with nasal polyps, CRSwNP) group, 15 cases (chronic rhinosinusitis without nasal polyos, CRSsNP) group, 11 cases recurrent CRSwNP group and 13 cases control group. Positive cells were counted under the microscope artificially, Mann-Whitney U analysis was applied for the ranked data, and one-way anova analysis was adopted to analyze the experimental group and control group. RESULT: (1) TLR2 and TLR4 expression had the same characteristics. Expression mainly concentrated in parts of the whole layer of epithelial basement membrane, cytoplasm of glandular cells, very few inflammatory cells such as monocytes and plasma cells in the cytoplasm, sometimes unknown cell nuclei positive expression. (2) The glandular cells were stained manual counting and color grading. TLR2 and TLR4 packet application Wilcoxon rank test Mann-Whitney U test analysis was not statistically significant (P > 0.05), measurement data within the group variance statistical difference between the groups (P < 0.05). CONCLUSION The Nasal mucosa can produce the innate immune factors TLR2 and TLR4. The different expression of TLR2 and TLR4 in the various clinical types of CRS suggests that they play the certain role in the pathogenesis of CRS.
Chronic Disease ; Epithelial Cells ; immunology ; metabolism ; Female ; Humans ; Immunohistochemistry ; Male ; Nasal Mucosa ; immunology ; metabolism ; Nasal Polyps ; immunology ; metabolism ; Rhinitis ; immunology ; metabolism ; Sinusitis ; immunology ; metabolism ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism

OBJECTIVETo investigate the TLR4 signaling in multiple myeloma cell proliferation and apoptosis.

METHODSTLR4 gene transcription and protein expression were detected by RT-PCR and PE flow cytometry staining; the cells proliferation were detected by MTT assay; doxorubicin-induced apoptosis of cells was detected by AnnexinV-PI double staining flow cytometry.

RESULTTLR4 gene transcription and protein expression was detected in the myeloma cell lines. Under the lipopolysaccharides (LPS) stimulation, MM1-s cells TLR4 positive proliferation significantly increased (P<0.05), but not found in U266 cells TLR4 negative; MM1-s cells showed the resistance to doxorubisin-induced apoptosis, but LPS did not protect doxorubicin-induced U266 cell apoptosis.

CONCLUSIONTLR4 signaling may play an important role both in multiple myeloma proliferation and survival.

Apoptosis ; physiology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Multiple Myeloma ; immunology ; metabolism ; pathology ; Signal Transduction ; 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

Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive secretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56(+) DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56(+) DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56(+) DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naïve T cells without prior activation. These data suggest that the CD56(+) DCs represent a novel mDC subset mixed with some pDC features. A CD4(+)CD56(+) hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs. However, we demonstrated that BPDCN is closer to CD56(+) DCs than pDCs by global gene-expression profiling. Thus, we propose that the CD4(+)CD56(+) neoplasm may be a tumor counterpart of CD56(+) mDCs but not pDCs.
Biomarkers ; metabolism ; CD56 Antigen ; genetics ; immunology ; Cell Lineage ; genetics ; immunology ; Dendritic Cells ; immunology ; metabolism ; pathology ; Gene Expression ; Hematologic Neoplasms ; genetics ; immunology ; pathology ; Humans ; Immunophenotyping ; Interferon Type I ; biosynthesis ; metabolism ; Interleukin-12 ; biosynthesis ; metabolism ; Interleukin-3 Receptor alpha Subunit ; genetics ; immunology ; Lectins, C-Type ; genetics ; immunology ; Membrane Glycoproteins ; genetics ; immunology ; Myeloid Cells ; immunology ; metabolism ; pathology ; Receptors, Immunologic ; genetics ; immunology ; Terminology as Topic ; Toll-Like Receptor 4 ; genetics ; immunology ; Toll-Like Receptor 7 ; genetics ; immunology ; Toll-Like Receptor 9 ; genetics ; immunology

This study was aimed to investigate the influence of TLR2 and TLR4 agonists on the migration and adhesion activity of umbilical cord blood (UCB) CD34(+) cells and to explore the underlying mechanism. The expression of TLR2 and TLR4 on UCB CD34(+) cells was detected with flow cytometry. The effect of TLR2 agonist (PAM3CSK4) and TLR2 agonist (LPS) on the migration and adhesion ability of UCB CD34(+) cells was evaluated with chemotaxis and adhesion assays. The results indicated that expression levels of TLR2 and TLR4 were (14.2 ± 3.8)%, (19.6 ± 4.1)% respectively. Compared with the control group, the migration activity of UCB CD34(+) cells toward SDF-1 decreased significantly in LPS group (p < 0.01). The adhesion activity was not altered significantly in LPS group. However, both the migration activity towards SDF-1 and the adhesion activity of UCB CD34(+) cells were not changed significantly in PAM3CSK4 group. Further study found that LPS did not affect the expression level of CXCR4 on CD34(+) cells, but could inhibit the spontaneous migration ability of CD34(+) cells. It is concluded that TLR4 activation can decrease the chemotaxis function of CD34(+) cells towards SDF-1, which may associate with the decreased spontaneous migration ability of CD34(+) cells.
Antigens, CD34 ; blood ; Cell Movement ; drug effects ; Cells, Cultured ; Chemokine CXCL12 ; Fetal Blood ; cytology ; immunology ; Humans ; Lipopeptides ; pharmacology ; Lipopolysaccharides ; pharmacology ; Toll-Like Receptor 2 ; agonists ; Toll-Like Receptor 4 ; agonists

OBJECTIVETo investigate the mechanism of Mycobacterium tuberculosis invasion to mouse dendritic cells (DC).

METHODSMycobacterium tuberculosis strain H37Rv was co-cultured with mouse DC2.4 cells.The mRNA expression of Toll-like receptor 2/4(TLR2/4) in DC2.4 cells was detected by fluorescent quantitative real-time PCR and the protein expression of nuclear factor κB(NF-κB) was assessed by Western blotting.The extracellular concentration of tumor necrosis factor α(TNF-α) was measured by ELISA methods during Mycobacterium Tuberculosis invasion.Indirect immunofluorescent staining and flow cytometry assay were used to detect the expression of CD80 and CD86 on DC2.4 cells before and after invasion.

RESULTSThe invasion of Mycobacterium tuberculosis in DC2.4 cells was observed after 2 h of co-incubation.The rates of invasion were (37.9±5.6)%,(51.2±7.6)%,(57.2±8.9)% and(63.9±6.8)% at 6,8,10 and 12 h after co-incubation,respectively.The mRNA expression level of TLR2 /4 was significantly increased at 6 h but decreased at 10 h after co-incubation.The expressions of NF-κB p65 and TNF-α were higher in DC2.4 cells after being invaded by 6,8,and 10 h and then gradually decreased.CD80 and CD86 expression were increased on DC2.4 at 6 h after co-incubation.

CONCLUSIONInvasion of Mycobacterium tuberculosis strain H37Rv to DC might enhance its antigen-presenting function through activation of TLR2/4-NF-kB signaling pathway.

Animals ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; Cells, Cultured ; Dendritic Cells ; immunology ; metabolism ; Mice ; Mycobacterium tuberculosis ; NF-kappa B ; metabolism ; Signal Transduction ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism