MicroRNA-141 regulates the expression level of ICAM-1 on endothelium to decrease myocardial ischemia-reperfusion injury.

A growing number of studies have suggested microRNAs (miRNAs) are involved in the modulation of myocardial ischemia-reperfusion (MI/R) injury; however, the role of endogenous miRNAs targeting endothelial cells (ECs) and its interaction with ICAM-1 in the setting of MI/R remain poorly understood. Our microarray results showed that miR-146a, miR-146b-5p, miR-155*, miR-155, miR-497, and miR-451 were significantly upregulated, whereas, miR-141 and miR-564 were significantly downregulated in the ECs challenged with TNF-α for 6 h. Real-time PCR analyses additionally validated that the expression levels of miR-146a, miR-155*, and miR-141 were consistent with the microarray results. Then, ICAM-1 was identified as a novel target of miR-141 by Target Scan software and the reporter gene system. Further functional experiments showed that elevated levels of miR-141 inhibited ICAM-1 expression and diminished leukocytes adhesion to ECs in vitro. In an in vivo murine model of MI/R injury, pretreatment with miR-141 mimics through the tail vein downregulated the expression level of ICAM-1 in heart and attenuated MI/R injury as evidenced by decreased infarct size and decline of serum cardial troponin I (cTnI) and lactate dehydrogenase (LDH) concentration. The cardioprotective effects of miR-141 mimics may be attributed to the decreased infiltration of CD11b(+) cells and F4/80(+) macrophages into ischemic myocardium tissue. In conclusion, our results demonstrate that miR-141, as a novel repressor of ICAM-1, is involved in the attenuation of MI/R injury via antithetical regulation of ICAM-1 and inflammatory cells infiltration. Thus miR-141 may constitute a new therapeutic target in the setting of ischemic heart disease.

Down regulation of TRAIL and FasL on NK cells by Cyclosporin A in renal transplantation patients.

TNF-related apoptosis-inducing ligand (TRAIL) and FasL can participate in cell mediated cytotoxicity via their death domain-mediated apoptotic signaling in the host-versus-graft disease occurred after renal transplantation. However, the effect of Cyclosporin A (CsA) commonly used as a drug to prevent and to treat renal transplant rejection, on these molecules have not been fully determined. In the present study, we found that with CsA administration, the expression of TRAIL and FasL predominantly on NK cells from renal transplantation patients was increased at day 5 after operation and went down to normal level on day 13. While, the levels of soluble TRAIL (sTRAIL) and sFasL in the serum increased within 25 days and went down to normal level three month later. In addition, we showed that a remarkable increase of TRAIL and FasL expression both on the surface of activated lymphocytes especially on NK cells and in the supernatants generated from mixed lymphocytes culture (MLC). Furthermore, the enhancement of these two molecules was greatly decreased by adding 500 ng/mL CsA at the beginning of MLC. We conclude that CsA may inhibit the transplant rejection partially by down-regulating the expression of TRAIL and FasL on NK cells.

[Prokaryotic expression, purification and identification of NY-ESO-1/GST fusion protein in E.coli].

AIM: To construct an expression plasmid for NY-ESO-1 gene and identify the expression of recombinant protein NY-ESO-1/GST in E.coli. METHODS: NY-ESO-1 segment was amplified from the testis cDNA library by RT-PCR and cloned into the prokaryotic expression vector pGEX4T-1 downstream tagged by GST to construct the expression plasmid pGEX-4T1-NY-ESO-1. The recombinant vector was transformed to BL21 (DE3) and NY-ESO-1/GST fusion protein was induced expression by IPTG. The protein was purified by urea elution and identified by SDS-PAGE and Western blotting. RESULTS: The NY-ESO-1 segment was successfully amplified and its sequence was identical with that published in GenBank. The BL21 (DE3) pLysS containing the pGEX-4T1-NY-ESO-1 expressed a M(r); 44 000 fusion protein under the induction of IPTG. The purity of the protein was 90%. Western blotting proved that NY-ESO-1/GST had a specific reaction with anti-GST mAb. CONCLUSION: The prokaryotic expression vector of NY-ESO-1 has been constructed and the fusion protein NY-ESO-1/GST of high purity is successfully expressed.

[The application of quantitative detection of cystatin C in evaluation of renal function after renal transplantation].

AIM: To establish ELISA method for quantitate the concentration of cystatin C (cys C) and to monitor the renal function of patients before and after renal transplantation. METHODS: Hybridomas secreting monoclonal antibodies (mAbs) against human cys C were produced and sandwich ELISA kit for quantitatively detecting cys C was established. Then the concentrations of serum cystatin C (Scys C) and urine cystatin C (Ucys C) from normal controls and 23 patients undergoing renal transplantation were detected and their relationship with serum creatinine (SCR) was analyzed. RESULTS: Seven hybridomas secreting anti-cys C mAbs were obtained. The sensitivity of the established ELISA kit reached 0.1 µg/L. The concentrations of Scys C and Ucys C of normal healthy controls were in accordance with other report. High correlations between Scys C or Ucys C and the level of SCR were observed (P<0.01). Rapid decline of Scys C and Ucys C concentrations was consistent with the decrease of SCR in the patients with normal course (NC) recovery after renal transplantation. However, Ucys C kept higher level within two weeks after the operation in patients with AR until the day 21. In patients with DGF, higher levels of Scys C, Ucys C and SCR were sustained within four weeks after renal transplantation. CONCLUSION: The sensitive ELISA kit for detection of cys C has been established. Importantly, there are the persistently high levels of Scys C and Ucys C in patients with AR or DGF, which can be used as a novel indicator for monitoring renal function after renal transplantation.

Murine monoclonal antibodies generated against mouse/rat hemokinin-1.

The mouse/rat hemokinin-1 (m/rHK-1) was discovered nearly 9 years ago. This molecule is a peptide comprising 11 amino acids. The m/rHK-1 was found to be mainly expressed in central immune organs like bone marrow, and was proven to have lymphopoietic roles in B and T lymphocyte development. m/rHK-1was also reported to have analgesic roles in rat spinal cord, in addition to other functions such as relaxing activity on coronary artery. Unlike its analogues SP, NKA, and NKB, m/rHK-1 does not express in the nervous system. To further study the distribution and function of m/rHK-1, we carried out conventional immunization and cell fusion procedures to acquire the hybridomas secreting specific monoclonal antibodies to m/rHK-1. In the 17 positive clones obtained, three antibodies named 1B12, 2B4, and 4G5 were shown representative in cross-reactivity against m/rHK-1 and its analogues by indirect ELISA, competitive indirect ELISA, and immunofluorescence assays. Among the three clones, the 2B4 monoclonal antibody appeared to be the high-titered and specific clone to m/rHK-1. Monoclonal antibodies to m/rHK-1 will function as good tools in the physiological study of m/rHK-1 in the near future.

Cancer/testis antigen CT45: analysis of mRNA and protein expression in human cancer.

CT45 is a cancer/testis gene that we previously identified by massively parallel signature sequencing. Encoded by a multigene family on chromosome X, CT45 showed restricted mRNA expression to normal testis and various cancers. In this study, monoclonal antibodies were generated against recombinant CT45 protein, and CT45 protein expression in normal and tumor tissues was evaluated by immunohistochemical analysis. In adult normal tissue, CT45 expression was restricted to testicular germ cells, detected as a nuclear protein mainly at the stage of primary spermatocytes. In tumors, CT45 protein expression correlated with the mRNA levels detected by quantitative RT-PCR, and most lung cancer and ovarian cancers with CT45 mRNA at levels >1% of testicular expression were CT45 protein-positive. In positive cases, CT45 showed expression patterns that ranged from diffuse strong staining to heterogeneous and patchy expression. In lung cancer, CT45 expression was least frequent in adenocarcinoma, more frequent in squamous cell carcinoma and neuroendocrine tumors. Using tissue microarrays, 376 lung cancer, 219 ovarian cancer and 155 breast cancer were evaluated for CT45 protein expression. The expression frequency was highest in ovarian cancer (37%), followed by lung cancer (13%) and lowest in breast cancer (<5%). Given the focal nature of CT45 expression in many cases, these numbers represented the minimal frequency of expression in these tumor types. In summary, the expression frequency and characteristics of CT45 expression are similar to other CT cancer vaccine targets currently in clinical trials, e.g., NY-ESO-1 and MAGE-A, suggesting CT45 as a potentially useful cancer target.

Generation of rat monoclonal antibodies against murine LAIR-1.

The leukocyte-associated Ig-like receptor 1 (LAIR-1), an inhibitory receptor bearing two immunoreceptor tyrosine-based inhibitory motifs (ITIM), is expressed on the majority of peripheral leukocytes, including NK cells, T cells, B cells, monocytes, dendritic cells, granulocytes, and thymocytes and is involved in immunologic regulation and hematopoiesis. Murine LAIR-1 (mLAIR-1) is the homolog molecule of human LAIR-1. Using mLAIR-1-Fc as the immunogen and the technique of rat B lymphocyte hybridoma, we raised three hybridoma cell lines secreting monoclonal antibodies (MAb) to mLAIR-1, designated FMU-mLAIR-1.1, -1.2, and -1.3. Rat immunoglobulin class and subclass of the MAb FMU-mLAIR-1.1 approximately 3 were determined to be IgM, IgG1, and IgM, respectively. All these MAbs can bind the mLAIR-1 in immunocytochemistry and immunohistochemistry. FMU-m LAIR-1.2 worked well not only in Western blot assay but also in recognizing natural LAIR-1 molecules on the surface of P388D1, J774, and WEHI3 cells, and mLAIR-1 cDNA-transfected CHO cells detected by FCM. Thus, successful production of rat anti-murine LAIR-1 monoclonal antibodies provides a new powerful tool for investigation of murine LAIR-1 function in mouse model, both in vitro and in vivo.

[Preparation of the monoclonal antibodies against human BORIS and the expression pattern of BORIS in normal and diseased human mammary tissues].

AIM: To prepare monoclonal antibodies(mAb) to BORIS antigen and analyze its expression pattern in breast cancer, benign breast disease and normal breast tissues. METHODS: Female BALB/c mice were immunized with recombination human BORIS protein. Hybridoma cell lines were established by hybridoma technique. BORIS antigen was detected by immunohistochemical (ICH) staining. RESULTS: Four clones of hybridomas stably secereting mAb against human BORIS were obtained. mAb FMMU-BORIS13 was selected to be employed in ICH. Positive staining was localized in the nuclei of the spermatocytes and spermatogoniums, which was consistent with the typical expression pattern of CT antigen. BORIS antigen was detected in 85%(94/110) of breast cancer, 95%(21/22) of benign breast diseases and 6 normal breast tissues(surrouding tumor free breast tissue). CONCLUSION: Four clones of anti-BORIS mAb have been successfully prepared. The expression of BORIS antigen is much stronger in breast cancer than that in benign breast disease and normal breast tissues, which indicate that BORIS may be involved in the pathogenesis of the breast cancer.

[Preparation and characterization of monoclonal antibodies against human CD112 (Nectin2/PRR2)].

AIM: To express and purify fusion protein of human CD112 extracellular region, prepare monoclonal antibodies (mAb) to CD112 and investigate the distribution of CD112 molecule. METHODS: The CD112-Fc fusion protein was expressed with gene recombinant technique in eukaryotic system and purified with affinity chromatography column. The BALB/c mice were immunized with purified CD112-Fc for preparation of mAb by hybridoma technique. The prepared mAbs were identified by indirect ELISA, Western blot and flow cytometry (FCM). Subsequently, the distribution of CD112 on different human cell lines was investigated by FCM. RESULTS: The effective expression plasmid pIg3C-CD112 was constructed, and human CD112-Fc was successfully expressed and purified with a purity of more than 90%. Nine clones of hybridoma were obtained, which were designated as FMU-CD112.1-FMU-CD112.9. FMU-CD112.1, 3, 6 and 8 specifically reacted with recombinant CD112-Fc protein in Western blot and FMU-CD112.1, 4, 6 and 8 could be used in FCM. The investigation of CD112 distribution showed high expression on the cell lines differentiated from epithelial cells. CONCLUSION: The hybridomas secreting mAbs to human CD112 are established successfully, which may lay the foundation for further research on the biological function of CD112.

Characterisation of monoclonal antibodies to the TNF and TNF receptor families.

Tumour necrosis factor (TNF) family ligands and their corresponding receptors play important roles in the immune system and are involved in immune regulation such as lymphoid development, cell proliferation, differentiation, activation and death. Antibodies against these ligands and receptors together with Fc-fusion proteins, have been particularly useful as immunological tools in addressing the underlying involvement of these proteins in these contexts and furthermore, have given us hope in using them as potential therapeutic agents. Over last few years, there have been many additions to these ever-growing TNF family ligands and their receptors. Here, we have generated and characterised a set of monoclonal antibodies, together with mAbs from the HLDA workshop, against DcR1, DcR2, DR4, DR5, TRAIL, APRIL, BAFF, BAFF-R, BCMA, and TACI, which may be useful in phenotypic and functional studies of the role of TNF and TNF receptor family in immune function and regulation in relation to health and disease.

[Regulation of soluble TRAIL and membrane TRAIL in Jurkat cells by PMA].

AIM: To investigate the regulation of soluble and membrane bound TNF-related apoptosis-inducing ligand (TRAIL) in Jurkt cells by phorbol myristic acctate (PMA), and the cytotoxicity of the two forms of TRAIL. METHODS: Jurkat cells were cultured in the presence of 40 ng/mL PMA for different time. The production of sTRAIL was determined by ELISA, and expression of mTRAIL was analyzed by indirect fluorescence staining and flow cytometry analysis. The cytotoxicites of sTRAIL and mTRAIL were detected by (51)Cr release assay, in which DR4/DR5-expressing Raji cells were employed as target cells. RESULTS: The expression of both sTRAIL and mTRAIL in Jurkat cells were upregulated by PMA. The level of sTRAIL in supernatant from PMA-stimulated Jurkat cell culture increased and reached peak at 48 hours after PMA treatment, whereas expression peak of mTRAIL was at 60 hours. Both sTRAIL and mTRAIL exhibited cytotoxicity against Raji cells. CONCLUSION: PMA, a PKC activator, can upregulate the expression of both sTRAIL and mTRAIL in Jurkat cells, and the two forms of TRAIL have cytotoxic activity.

[Apoptosis-inducing ligand TRAIL can be recruited to lipid rafts].

AIM: To investigate the relationship between tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) and cell membrane microdomain lipid rafts. METHODS: The expression of TRAIL on K562 cells was detected by indirect immunofluorescence staining and flow cytometry. The lipid rafts on K562 cells were detected with FITC-labeled cholera toxin B subunit (CTx-FITC) which bound to the GM1 glycosphingolipid in lipid rafts. The lipid rafts were then cross-linked with an anti-FITC mAb after binding with CTx-FITC. The localization of TRAIL on K562 cells was analyzed with rabbit anti-TRAIL antibody, Cy3-labeled goat-anti-rabbit IgG (Cy3-labeled GAR) and laser scanning confocal microscope. RESULTS: The cross-linking of lipid rafts appeared at 20 minutes, reached peak at 30 minutes, and weakened around 40 minutes. After the cells were labeled with CTx-FITC and anti-FITC mAb TRAIL was aggregated in the cross-linked lipid rafts. CONCLUSION: The anti-FITC mAb could be used for cross-linking of lipid rafts. TRAIL can be recruited to lipid rafts.

[Construction and expression of human EpCAM eukaryotic expression vectors and identification of their products].

AIM: To construct EpCAM eukaryotic expression vectors pIg-EpCAM and pEGFP-EpCAM and to express them in COS7 cells. METHODS: EpCAM cDNA was amplified by PCR and then inserted into the pIg and pEGFP vectors respectively to construct recombinant vectors pIg-EpCAM and pEGFP-EpCAM. The two recombinant vectors were transfected into COS7 cells under the mediation of liposome. The expressed EpCAM-Ig fusion protein was detected by Western blot. The expression of EpCAM-GFP fusion protein was observed under fluorescence microscope. RESULTS: DNA sequencing demonstrated that EpCAM was correctly cloned into the two vectors. The culture supernatant of the pIg-EpCAM-transfected COS7 cells could bind effectively to mAb against human IgG Fc. Green fluorescence distributed evenly in the cytoplasm and nuclei of pEGFP-transfected COS7 cells, whereas in pEGFP-EpCAM transfected COS7 cells, green fluorescence distributed mainly on the surface of the cells. CONCLUSION: Two EpCAM eukaryotic expression vectors have been constructed and expressed successfully, which lays the foundation for functional research of EpCAM and for preparation of mAb to EpCAM.

[The inhibition of TNF-induced NF-kappaB nuclear translocation in ECV304 cells by mAbs against human TNF].

AIM: To identify the inhibition of TNF-induced NF-kappaB nuclear translocation by three anti-human TNF mAbs, D2, E6 and F6. METHODS: TNF solutions were pretreated with mAbs D2, E6 and F6 as well as control mAb at 37 degrees Celsius for 1 h, respectively, and then they were added to ECV304 cell cultures. After 1 hour, the cells were harvested and nuclear proteins were extracted. The NF-kappaB activity in nuclear extract was detected by electrophoretic mobility shift assay (EMSA). RESULTS: All of the three anti-TNF mAbs could inhibit TNF-induced NF-kappaB nuclear translocation in a dose-dependent manner. At the concentrations of 10 mg/L and 0.1 mg/L, the inhibition rates of mAb D2, E6 and F6 were 94.2% and 75.1%, 64.9% and 28.6%, 70.3% and 49.5% respectively, while the inhibition rate of control mAb was only 20.0% and 11.1%. CONCLUSION: mAbs D2, E6 and F6 can specifically inhibit TNF-induced NF-kappaB nuclear translocation, which lays the foundation for preparation of therapeutic chimeric anti-human TNF antibody for treatment of infectious and autoimmune diseases.

Preparation and characterization of a set of monoclonal antibodies to TRAIL and TRAIL receptors DR4, DR5, DcR1, and DcR2.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo 2L) is a novel cytotoxic ligand belonging to TNF superfamily. Among TRAIL receptors, death receptor 4 (DR4) and DR5 containing death domain (DD) in their cytoplasmic region mediate apoptosis-signaling upon TRAIL binding, while decoy receptor 1 (DcR1) and DcR2 with a truncated or non-functional DD play "decoy" role. The interaction of TRAIL and TRAIL receptors plays important roles both in immunoregulation and immune pathogenesis of some diseases. In this study, we raised hybridomas secreting monoclonal antibodies against TRAIL (FMU1.1, 1.2, 1.3), DR4 (FMU1.4), DR5 (FMU1.5, 1.6), DcR1 (FMU1.7) and DcR2 (FMU1.8, 1.9). These MAbs could be used for fluorescent staining and flow cytometry (FCM) analysis as well as immunohistochemistry (IHC). Moreover, FMU1.1, 1.3, 1.4 and 1.5 could be used as coating antibodies paring corresponding polyclonal antibodies to develop sandwich ELISAs to quantitate the soluble TRAIL (sTRAIL), sDR4 or sDR5 in serum samples respectively. In addition, cross-linking of DR4/DR5 by FMU1.4 or FMU1.5 MAbs could induce apoptosis of some DR4/DR5-expressing tumor cells. Thus, this set of monoclonal antibodies against TRAIL or TRAIL receptors may be useful in expression phenotypic and functional study of TRAIL and TRAIL receptors.