The role of Toll-like receptors in chemoradiotherapy-induced gastrointestinal mucositis / 口腔疾病防治

@#Mucositis is a common gastrointestinal complication in cancer patients undergoing chemoradiotherapy, including oral mucositis and gastrointestinal mucositis, with clinical manifestations of oral ulcers, vomiting, diarrhea and pain that seriously reduce the quality of life of patients and even affect anticancer therapy. Toll-like receptor (TLR) are important receptors involved in innate immunity and in the development of chemoradiation-induced mucositis by mediating the effect between microorganisms and the host. A comprehensive understanding of the role of TLR in mucositis is helpful to guide the prevention and treatment of mucositis. This paper reviews the available studies on TLR and mucositis. The results of the literature review indicate that different TLR have different roles in chemoradiation-induced mucositis: TLR2 is an important receptor in the inflammatory cascade of chemoradiation-induced mucositis; TLR4 activation can increase gastrointestinal mucosal inflammation and lead to oral epithelial ulceration; TLR5 agonists can reduce the degree of radiation-induced mucositis damage; and antagonizing or knocking out TLR9 can reduce chemoradiation-induced gastrointestinal mucositis. However, no TLR agonists or inhibitors have yet been applied in clinical practice, and additional studies are needed to explore the role of different TLR in mucositis in the future to provide a reference for the precise prevention and treatment of chemoradiation-induced mucositis.

Impact of TLR5 and NLRC4 activation on proliferation of different breast cancer cell lines / 中国免疫学杂志

Objective:To explore the impact of TLR5 and NLRC4 activation on the proliferation of different breast cancer cell lines,MCF-7 and MDA-MB-23 i.Methods:Induction,expression,purification and identification of recombiant flagellin,including FliC (activating both TLR5 and NLRC4),FliC△90-97 (unable to activate TLR5),FliC-L3A (unable to activate NLRC4),FliC△90-97:L3A (unable to activate both TLR5 and NLRC4).Using different concentration of recombinant flagellin to stimulate MCF-7 and MDA-MB-231 cell lines,72 h later,the proliferation of tumor cells were detected with CCK8.We also used soft AGAR forming experiments to detect the inhibition ratio of recombinant flagellin on breast cancer cell lines.Briefly,1 000 cells were plated in the 6-well plate,then stimulated with 1 μg/ml recombinant flagellin,14 days later,the number of cloning were counted after crystal violet staining.Results:After stimulation with four recombinant flagellins at the concentration of 0.1 μ,g/ml,the inhibition ratio on MCF-7 reached 30％,and FliC△90-97 were dose-dependent on the inhibition of MCF-7 proliferation.At the concentration of 1 μg/ml,FliC-L3A which only activated TLR5 showed stronger inhibition ratio than FliC.FliC△90-97:L3A which did not activate both TLR5 and NLRC4 also inhibited the proliferation of MCF-7.After adding transfection reagent,four recombinant flagellins showed inhibition effect on MDA-MB-231.Conclusion:Flagellin can inhibit the proliferation of MCF-7 and MDA-MB-231,and the mechanism of inhibition on the proliferation were not TLR5 and NLRC4 pathway dependent.There might exist new mechanisms to explain this phenomenon.

Role of TLR5 in infectious diseases / 中华微生物学和免疫学杂志

Toll-like receptor 5 (TLR5) is one of the pattern recognition receptors and recognizes the flagellin protein of bacteria.It activates innate immune responses and induces production of a series of cytokines.TLR5 functions as a bridge linking innate and adaptive immunities.It is known that TLR5 plays an important role in the occurrence and development of certain infectious diseases.This review summarizes the relationships of TLR5 polymorphisms with the development of infectious diseases and discusses the possible pathogenesis.

Expression and location of TLR5 and NLRC4 in different breast cancer cell lines / 中国免疫学杂志

Objective:To explore the expression and location of TLR5 and NLRC4 on different breast cancer cell lines MDA-MB-231,MCF-7 and MDA-MB-435 and TLR5 activation in breast cancer cell line by recombinant flagellin . Methods:The mRNA level of TLR5 and NLRC4 in MDA-MB-231, MCF-7 and MDA-MB-435 cell were detected with quantitative Real-time PCR and TLR5 expression and location in MDA-MB-231 and MCF-7 cell were detected with Flow cytometry. Induction,expression,purification and i-dentification of recombiant flagellin,including FliC (activating both TLR5 and NLRC4),FliC△90-97(unable to activate TLR5),FliC-L3A (unable to activate NLRC4),FliC△90-97:L3A (unable to activate both TLR5 and NLRC4). 1 μg/ml recombinant flagellin were used to stimulate MCF-7 cell lines,12 h later,the supernate were collected,and ELISA was performed to assess the secretion of IL-8. Results:The mRNA level of TLR5 in MCF-7 cell was 1 700 folds higher than that of MDA-MB-435. TLR5 was expressed in MCF-7 cell surface and ctyosol,while expressed only in cytosol in MDA-MB-231 cell. FliC and FliC-L3A,which were able to activate TLR5 pathway,stimualted MCF-7 cell line to secret IL-8,but FliC△90-97 and FliC△90-97:L3A did not. Conclusion:TLR5 and NLRC4 have been expressed in different breast cancer lines,but there exists difference on the expression level and location of TLR5. Expression level of TLR5 and NLRC4 in MCF-7 cell were higher than other breast cancer lines. TLR5 receptor which is expressed on the surface of breast cancer cell can be activated by flagellin,and these work also provide us experimental basis to further understand the impact of TLR5 activation on breast cancer cell proliferation.

Impact of TLR5 and NLRC4 activation on innate immune cells in mice / 中国免疫学杂志

Objective:To investigate the impact of recombinant flagellin targeting TLR5 and NLRC4 simultaneously or respectively on innate immune cells in mice. Methods: Induction,expression,purification and identification of recombiant FliC,which were FliC(activating both TLR5 and NLRC4);FliCΔ90-97(unable to activate TLR5),FliC-L3A(unable to activate NLRC4),FliCΔ90-97:L3A(unable to activate both TLR5 and NLRC4). The mice were divided into five groups,namely group FliC,FliC-L3A,FliCΔ90-97,FliCΔ90-97:L3A and PBS,which were injected with 100μl PBS or 10μg recombinant flagellin intraperitoneally,three mice in each group. 12 h later,the mice were executed using dislocation of cervical vertebra and the splenic and peritoneal cells were isolated. The spleen was grinded into single-cell suspension. The proportion of neutrophils,NK cells,DCs and the expression level of CD80 and CD86 on DCs were evaluated with flow cytometry. Results:Group FliC,group FliC-L3A and group FliCΔ90-97 shared the similar proportion of neutrophils in peritoneal cavity ( P>0. 05 ) , and all of which were significantly higher than group PBS and group FliCΔ90-97 ( P<0. 01),and NK cells also showed the similar trend. Compared with group FliCΔ90-97 and FliCΔ90-97:L3A,the mean fluorescence intensities(MFIs) of CD80 and CD86 in group FliC and FliC-L3A increased significantly(P<0. 01). The proportion of Treg in spleen was highest among all groups. Conclusion:Activation of TLR5 and NLRC4 had similar chemotaxis of neutrophils and NK cells. The ex-pression of CD80 and CD86 on DCs were upregulated after stimulation by flagellin and TLR5-dependent. Activation of TLR5,but not NLRC4,increased the proportion of Treg in spleen.

Evaluation of Toll-like, chemokine, and integrin receptors on monocytes and neutrophils from peripheral blood of septic patients and their correlation with clinical outcomes

Recognition of pathogens is performed by specific receptors in cells of the innate immune system, which may undergo modulation during the continuum of clinical manifestations of sepsis. Monocytes and neutrophils play a key role in host defense by sensing and destroying microorganisms. This study aimed to evaluate the expression of CD14 receptors on monocytes; CD66b and CXCR2 receptors on neutrophils; and TLR2, TLR4, TLR5, TLR9, and CD11b receptors on both cell types of septic patients. Seventy-seven septic patients (SP) and 40 healthy volunteers (HV) were included in the study, and blood samples were collected on day zero (D0) and after 7 days of therapy (D7). Evaluation of the cellular receptors was carried out by flow cytometry. Expression of CD14 on monocytes and of CD11b and CXCR2 on neutrophils from SP was lower than that from HV. Conversely, expression of TLR5 on monocytes and neutrophils was higher in SP compared with HV. Expression of TLR2 on the surface of neutrophils and that of TLR5 on monocytes and neutrophils of SP was lower at D7 than at D0. In addition, SP who survived showed reduced expression of TLR2 and TLR4 on the surface of neutrophils at D7 compared to D0. Expression of CXCR2 for surviving patients was higher at follow-up compared to baseline. We conclude that expression of recognition and cell signaling receptors is differentially regulated between SP and HV depending on the receptor being evaluated.

CBLB502 Protects mice radiation pneumonitis and pulmonary fibrosis / 军事医学

Objective To investigate the protective effect of CBLB 502 on radiation pneumonitis and pulmonary fibrosis for confirming the feasibility of CBLB502 as a clinical anti-radiation drug release.Methods With a single 20 Gy irradia-tion, C57BL/6J mice was sacrificed on 24 h, 1 month, 3 months and 5 months and lung tissue was assayed by TUNEL method for apoptosis of alveolar epithelial cells and endothelial cells , HE staining showing fibrosis changes , immunohisto-chemistry detecting the expression of specific indicators , as well as pathological changes of the fur and skin radiated site . Results CBLB502 inhibits apoptosis in mice alveolar epithelial cells and vascular endothelial cells after irradiation , slowing the process of pulmonary fibrosis , while reducing the expression of laminin and maintaining the expression of surfac-tant protein B, and the skin inflammation also significantly reduced .Conclusion CBLB502 could alleviate the occurrence of radiation pneumonitis and pulmonary fibrosis as well as radiation-induced skin injury .

TLR5-dependent immunogenicity of a recombinant fusion protein containing an immunodominant epitope of malarial circumsporozoite protein and the FliC flagellin of Salmonella Typhimurium

Recently, we described the improved immunogenicity of new malaria vaccine candidates based on the expression of fusion proteins containing immunodominant epitopes of merozoites and Salmonella enterica serovar Typhimurium flagellin (FliC) protein as an innate immune agonist. Here, we tested whether a similar strategy, based on an immunodominant B-cell epitope from malaria sporozoites, could also generate immunogenic fusion polypeptides. A recombinant His6-tagged FliC protein containing the C-terminal repeat regions of the VK210 variant of Plasmodium vivax circumsporozoite (CS) protein was constructed. This recombinant protein was successfully expressed in Escherichia coli as soluble protein and was purified by affinity to Ni-agarose beads followed by ion exchange chromatography. A monoclonal antibody specific for the CS protein of P. vivax sporozoites (VK210) was able to recognise the purified protein. C57BL/6 mice subcutaneously immunised with the recombinant fusion protein in the absence of any conventional adjuvant developed protein-specific systemic antibody responses. However, in mice genetically deficient in expression of TLR5, this immune response was extremely low. These results extend our previous observations concerning the immunogenicity of these recombinant fusion proteins and provide evidence that the main mechanism responsible for this immune activation involves interactions with TLR5, which has not previously been demonstrated for any recombinant FliC fusion protein.

Association of Toll-Like Receptor 5 Gene Polymorphism with Susceptibility to Ossification of the Posterior Longitudinal Ligament of the Spine in Korean Population

OBJECTIVE: Ossification of the posterior longitudinal ligament (OPLL) has a strong genetic component. Specific gene polymorphisms may be associated with OPLL in several genes which regulate calcification in chondrocytes, change of extracellular collagen matrix and secretions of many growth factors and cytokines controlling bone morphogenesis. Toll-like receptor 5 (TLR5) may play a role in the pathogenesis of OPLL by intermediate nuclear factor-kappa B (NF-kappaB). The current study focused on coding single nucleotide polymorphisms (SNPs) of TLR5 for a case-control study investigating the relationship between TLR5 and OPLL in a Korean population. METHODS: A total of 166 patients with OPLL and 231 controls were recruited for a case-control association study investigating the relationship between SNPs of TLR5 gene and OPLL. Four SNPs were genotyped by direct sequencing (rs5744168, rs5744169, rs2072493, and rs5744174). SNP data were analyzed using the SNPStats, SNPAnalyzer, Haploview, and Helixtree programs. Multiple logistic regression analysis with adjustment for age and gender was performed to calculate an odds ratio (OR). RESULTS: None of SNPs were associated with OPLL in three alternative models (codominant, dominant, and recessive models; p > 0.05). A strong linkage disequilibrium block, including all 4 SNPs, was constructed using the Gabriel method. No haplotype was significantly associated with OPLL in three alternative models. CONCLUSION: These results suggest that Toll-like receptor 5 gene may not be associated with ossification of the posterior longitudinal ligament risk in Korean population.

A Bacterial Flagellin, Vibrio vulnificus FlaB, Induces Human Dendritic Cell Maturation

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.