Profiling of the pattern of the human TRB/IGH-CDR3 repertoire in primary biliary cholangitis patients.

INTRODUCTION: Primary biliary cholangitis (PBC) is characterized by lymphocyte cell-induced immune destruction of cholangiole. However, the immunological characteristics of peripheral blood cells in PBC patients remain unknown. This study was designed to reveal the differences in the immunological characteristics between PBC patients and healthy adults. METHODS: We performed high-throughput sequencing to determine the TRB-CDR3 and IGH-CDR3 repertoires of T and B cells in 19 healthy controls and 29 PBC patients. Different immunological characteristics, such as distinctive complementarity determining region 3 (TRB-CDR3) lengths, usage bias of V and J segments, and random nucleotide addition were identified in PBC and healthy control (HC) groups. RESULTS: The diversity of TRB-CDR3 was significantly lower in the PBC group compared with the HC group. CDR3 and the N addition length distribution were significantly changed compared with the HC group. It appeared that the PBC group had more short N additions and the HC group had more long N additions in the TRB-CDR3 repertoire. The results also revealed a set of PBC-associated clonotypes compared with the HC group. CONCLUSION: This study suggested that PBC is a complex autoimmune disease process with evidence of different TRB-CDR3 rearrangements compared with healthy adults that share IGH-CDR3 peptides with some autoimmune diseases. This new insight may contribute to a better understanding of the immune functions of PBC patients and benefit efficient applications of PBC diagnosis and treatments.

Nitrate Accumulation and Leaching in Surface and Ground Water Based on Simulated Rainfall Experiments.

To evaluate the process of nitrate accumulation and leaching in surface and ground water, we conducted simulated rainfall experiments. The experiments were performed in areas of 5.3 m2 with bare slopes of 3° that were treated with two nitrogen fertilizer inputs, high (22.5 g/m2 NH4NO3) and control (no fertilizer), and subjected to 2 hours of rainfall, with. From the 1st to the 7th experiments, the same content of fertilizer mixed with soil was uniformly applied to the soil surface at 10 minutes before rainfall, and no fertilizer was applied for the 8th through 12th experiments. Initially, the time-series nitrate concentration in the surface flow quickly increased, and then it rapidly decreased and gradually stabilized at a low level during the fertilizer experiments. The nitrogen loss in the surface flow primarily occurred during the first 18.6 minutes of rainfall. For the continuous fertilizer experiments, the mean nitrate concentrations in the groundwater flow remained at less than 10 mg/L before the 5th experiment, and after the 7th experiment, these nitrate concentrations were greater than 10 mg/L throughout the process. The time-series process of the changing concentration in the groundwater flow exhibited the same parabolic trend for each fertilizer experiment. However, the time at which the nitrate concentration began to change lagged behind the start time of groundwater flow by approximately 0.94 hours on average. The experiments were also performed with no fertilizer. In these experiments, the mean nitrate concentration of groundwater initially increased continuously, and then, the process exhibited the same parabolic trend as the results of the fertilization experiments. The nitrate concentration decreased in the subsequent experiments. Eight days after the 12 rainfall experiments, 50.53% of the total nitrate applied remained in the experimental soil. Nitrate residues mainly existed at the surface and in the bottom soil layers, which represents a potentially more dangerous pollution scenario for surface and ground water. The surface and subsurface flow would enter into and contaminate water bodies, thus threatening the water environment.

Application of modified export coefficient method on the load estimation of non-point source nitrogen and phosphorus pollution of soil and water loss in semiarid regions.

Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of "soil and water flow together", and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source composition of TP (38.1 %) is rural life; the maximum contribution rates of TN and TP in Baota district are 36.26 and 39.26 %, respectively. Results may provide data support for NPS pollution prevention and control in the loess hilly and gully region and also provide scientific reference for the protection of ecological environment of the Loess Plateau in northern Shaanxi.

Modeling the impact of soil and water conservation on surface and ground water based on the SCS and Visual MODFLOW.

Soil and water conservation measures can impact hydrological cycle, but quantitative analysis of this impact is still difficult in a watershed scale. To assess the effect quantitatively, a three-dimensional finite-difference groundwater flow model (MODFLOW) with a surface runoff model-the Soil Conservation Service (SCS) were calibrated and applied based on the artificial rainfall experiments. Then, three soil and water conservation scenarios were simulated on the sand-box model to assess the effect of bare slope changing to grass land and straw mulching on water volume, hydraulic head, runoff process of groundwater and surface water. Under the 120 mm rainfall, 60 mm/h rainfall intensity, 5 m(2) area, 3° slope conditions, the comparative results indicated that the trend was decrease in surface runoff and increase in subsurface runoff coincided with the land-use converted from bare slope to grass land and straw mulching. The simulated mean surface runoff modulus was 3.64×10(-2) m(3)/m(2)/h in the bare slope scenario, while the observed values were 1.54×10(-2) m(3)/m(2)/h and 0.12×10(-2) m(3)/m(2)/h in the lawn and straw mulching scenarios respectively. Compared to the bare slope, the benefits of surface water reduction were 57.8% and 92.4% correspondingly. At the end of simulation period (T = 396 min), the simulated mean groundwater runoff modulus was 2.82×10(-2) m(3)/m(2)/h in the bare slope scenario, while the observed volumes were 3.46×10(-2) m(3)/m(2)/h and 4.91×10(-2) m(3)/m(2)/h in the lawn and straw mulching scenarios respectively. So the benefits of groundwater increase were 22.7% and 60.4% correspondingly. It was concluded that the soil and water conservation played an important role in weakening the surface runoff and strengthening the underground runoff. Meanwhile the quantitative analysis using a modeling approach could provide a thought for the study in a watershed scale to help decision-makers manage water resources.

[Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0.925 Pa, respectively.

[Prepared the monoclonal antibody associated with hepatocellular carcinoma and analyzed its epitope].

AIM: To prepare the monoclonal antibodies associated with hepatocellular carcinoma (HCC) for diagnosis. METHODS: 3 BALB/c mice were immunized with high metastasis characteristic HCC cells (HCCLM-6). The splenocytes from the immunized mice were fused with murine myeloma cells (Sp2/0). The hybridoma cells were screened by ELISA after coating with the total protein and the culture supernatant of HCCLM-6 cells. The mAbs were characterized by immunohistochemical staining in the HCC tissues, and by indirect immunofIuorescent staining in different cell lines. The antigen and epitope recognized by the mAbs were identified by the screening premade Uni-ZAP human liver cDNA expression library. RESULTS: Twenty-eight hybridoma cells secreting mAbs were established. One clone of the hybridomas, QGA062, secreted specific mAb associated with HCC. The antigen recognized by the mAb QGA062 was identified as fibronectin (FN), and the epitope was localized among the peptide YTVSLVAIKGNQESPK. CONCLUSION: The mAb against a HCC-associated epitope in FN is established and characterized, will be a very useful reagent for diagnosis of HCC.

[Preparation and identification of PON2 monoclonal antibodies.].

AIM: To prepare and characterize the mouse monoclonal antibodies against human PON2 (paraoxonase 2). METHODS: A fragment of human PON2 gene of low homology with mice but of strong hydrophilicity and immunogenicity was selected for recombinant expression. Mice were immunized with the purified HIS fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 monoclonal antibodies were characterized by Western blot and indirect immunofluorescence. RESULTS: HIS-PON2 and GST-PON2 fusion protein was highly expressed in E.coli with a molecular weight of 40 kDa and 46 kDa. Western blot analysis proved that the established monoclonal antibodies could specifically recognize the target proteins expressed in E.coli expression system. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of HepG2 cells. CONCLUSION: The monoclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells, Which can be used for further functional study of PON2 protein.

[Preparation and identification of monoclonal antibody against enoyl-CoA hydratase 1].

OBJECTIVE: To prepare monoclonal antibodies (mAbs) against enoyl-CoA hydratase 1 (ECH1). METHODS: Normal human liver tissues were homogenized, and the mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to prepare mAbs by routine hybridoma technique. The mAbs were characterized by ELISA, Western blotting and immunohistochemistry. The specificity of the antibody was identified by mass spectrometry (MS) following immunoprecipitation (IP) and confirmed by Uni-ZAP expression library screening. RESULTS: One clone of the hybridoma BGB095 secreting specific mAb against ECH1 was obtained. The mAb was identified to belong to Ig subclass IgG1 and could be used in ELISA, Western blotting, immunohistochemistry, and immunoprecipitation. CONCLUSION: A hybridoma cell line stably secreting specific mAb against ECH1 has been established. The specific mAb against ECH1 can be of great value for functional and distribution studies of ECH1.

[Expression of procalcitonin and characterization of antibodies against PCT].

AIM: To construct the expression vectors of procalcitonin (PCT), prepare polyclonal antibodies (pAbs) and monoclonal antibodies (mAbs) against PCT and identify their specific biological activity. METHODS: The recombinant expression plasmids of pGEX-4T-1-PCT and PET-32a-PCT were constructed using thyroid carcinoma cell line (TT cell) cDNA as template. The fusion protein of His-PCT was expressed in E.coli and used as immunogen. The specificity of antiserum against human PCT was characterized by ELISA, Western blot and indirect immunofluorescence. The mAbs against human PCT were identified by Western blot and indirect immunofluorescence. RESULTS: The recombinant expression plasmids of pGEX-4T-1-PCT and PET-32a-PCT were constructed and the fusion protein of His-PCT was expressed and purified. The antiserum against human PCT was prepared and the titer detected by ELISA was 1:256 000. The pAb specifically recognized the recombinant human PCT. Eight hybridoma cell lines secreting specific mAbs against PCT were established. The mAbs recognized the recombinant human PCT and four of them recognized the native PCT of TT cytoplasm in immunofluorescent assay. CONCLUSION: The successful preparation of polyclonal and monoclonal antibodies against human PCT is beneficial to further research into the pathological and physiological functions of PCT in severe bacterial infection and sepsis.

[Preparation and preliminary application of rabbit anti-human PON2 antibodies(paraoxonase-2)].

AIM: To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2). METHODS: A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence. RESULTS: The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells. CONCLUSION: The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

[Preparation, characterization and application of monoclonal antibody against CPS1].

AIM: To prepare and characterize the monoclonal antibody (mAb) against human carbamyl phosphate synthetase I (CPSI) and make a study of its application. METHODS: Normal human liver tissues were homogenized, and their mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to prepare mAb using the routine hybridoma technique. The mAb was detected by ELISA, Western blot immunohistochemistry and immunofluorecent staining. The specificity of mAb was identified by mass spectrometry (MS) and immunoprecipitation (IP) and then confirmed by Uni-ZAP expression library screening. The antibody was used to isolate potential enzymatic complexes by immunocapturing. RESULTS: Three hybridoma cell lines BEH045, ACB271 and BFG021 secreting specific mAb against CPS1 were obtained. The Ig subclass of the mAb was IgG(1), which was used in ELISA, Western blot immunohistochemistry, immunoprecipitation, immunofluorecent staining and the isolation of potential enzymatic complexes. CONCLUSION: A hybridoma cell line which can secre specific mAb against CPSI stably has been established. The specific mAb against CPSI is of value to the research into the functions and distribution of CPSI.

[Generation and characterization of monoclonal antibody against HSD11B1].

AIM: To generate and identify monoclonal antibodies (mAb) against homo sapiens hydroxysteroid 11-beta dehydrogenase 1 (HSD11B1). METHODS: Normal human liver tissues were homogenized, and mitochondria were isolated by differential centrifugation. The total mitochondrial proteins were used to immunize BALB/c mice to generate mAb by hybridoma technique. The mAb were characterized by ELISA, Western blot and immunohistochemistry. The antibody specificity was identified by immunoprecipitation (IP), and confirmed by Uni-ZAP expression library screening. RESULTS: One hybridoma CBF245 secreting specific mAb against HSD11B1 was established. The Ig subclass of this mAb was IgG1, and it could be used in ELISA, Western blot, immunohistochemistry. Our data showed that the antigen recognized by CBF245 mAb was localized in the hepatocyte cytoplasm, with molecular weight of M(r) 35 000 in the mitochondria of human liver tissue. The CBF245 mAb was further confirmed by immunoscreening of Uni-ZAP XR liver cDNA expression library. CONCLUSION: A hybridoma cell line stably secreting specific mAb against HSD11B1 is established and characterized. This mAb reacted with HSD11B1 in ELISA, Western blot, immunohistochemistry assay, IP, and would be very useful for the HSD11B1 studies.

[Preparation and characterization of antibodies against clusterin].

AIM: To prepare rabbit polyclonal antibodies (pAb) and mouse monoclonal antibodies (mAbs) against human clusterin(CLU) and characterize these antibodies' properties. METHODS: CLU fragment was amplified from human liver cDNA library, and recombinant expression vectors pGEX-4T-1-CLU and PET-32a-CLU were constructed. GST-CLU fusion protein was expressed in E.coli and then used as the immunogen. Properties of antiserum against human CLU were identified by ELISA, Western blot, and the mAbs against human CLU was characterized by Western blot, indirect immunofluorescent staining and immunohistochemistry staining. RESULTS: The GST-CLU fusion protein was highly expressed with a molecular weight of M(r)54,000. Western blot analysis proved that the rabbit pAb could specifically recognize 52,000 and 58,000 proteins in human liver total protein. All of the nine established mAbs recognized recombinant human CLU protein, two of which specifically bound to proteins in the cytoplasm of HepG2 cells and four of which specifically bound to proteins in the cytoplasm of adult liver tissue. CONCLUSION: pAb and mAbs against human CLU were successfully prepared, which will provide efficient tools for functional studies of CLU expressed in human tumors.

[Method of antibody analysis based on visual protein array].

AIM: To establish a novel method for antibody analysis based on visual protein microarray. METHODS: The antibodies spotted on the aldehyde-modified slides were incubated with corresponding antigens labeled by biotin, followed by silver enhancement detection method, and the chromogenic images were scanned by CCD camera. RESULTS: The affinity and specificity of each antibody was assayed by this method and six antibodies were found to have higher specificity than the others. A detection limit of 0.4 microg/L was obtained for anti-globulinIIIC013, anti-albumin HPSIIB007, and anti-albumin HPSIIIB007. CONCLUSION: This method is simple, fast and visual. In addition, it needs less sample amount than traditional immunoassay and has potential to achieve high throughput.

[Generation and characterization of monoclonal antibody against GRHPR].

AIM: To generate monoclonal antibodies (mAb) against glyoxylate reductase/hydroxypyruvate reductase (GRHPR). METHODS: Normal human liver tissues were homogenized, and human liver cytosolic proteins were isolated by centrifugation. The total human liver cytosolic proteins were used to immunize BALB/c mice to prepare mAb by hybridoma technique. The mAbs were detected by ELISA, Western blot, and immunohistochemistry. The antibody specificities were identified by mass spectrometry (MS) following immunoprecipitation (IP) and confirmed by Uni-ZAP expression library screening. RESULTS: One hybridoma cell line, ADB291, secreting specific mAb against GRHPR was established. The Ig subclass of the mAb was IgG1(kappa). Data from immunohistochemistry showed that ADB291 can recognize hepatocyte cytoplasm. ADB291 mAb was used to isolate its protein antigen by IP. Proteins captured by the mAb were loaded to SDS-PAGE and subjected to Western blot and MALDI-TOF MS analysis. lambda expression Uni-ZAP XR pre-made liver cDNA library was screened with ADB291 hybridoma supernatants. All of our data demonstrated that ADB291 mAb specially reacted with GRHPR. CONCLUSION: A hybridoma cell line stably secreting specific mAb against GRHPR is established. The specific mAb against GRHPR would be very useful for the studies of GRHPR functions and distribution.

[Identification of protein antigen for antibody DBD02 by biopanning of T7 phage display library].

AIM: To identify the specificity of mAb DBD02, we developed and optimized a new method by biopanning of T7 Select human liver cDNA phage display library. METHODS: After two rounds of biopanning, eluted phages were subjected to Dot blot using mAb DBD02 as primary antibody. The positive PFUs (plaque forming unit) which recognized by DBD02 were further confirmed by Western blot, PCR and sequencing. RESULTS: The antigen recognized by DBD02 was identified as alcohol dehydrogenase. And the epitope for mAb DBD02 was further mapped within a peptide of 22 amino acids (QDYKKPIQEVLKEMTDG-GVDFS). CONCLUSION: Our data indicate that biopanning of T7 phage display library by mAbs is time, cost, and labor-saving and specific tool for protein antigen identification.

[Preparation and identification of monoclonal antibody against Homo sapiens hemoglobin alpha 2 (HBA2)].

This study was purposed to prepare and identify monoclonal antibodies (McAbs) against Homo sapiens hemoglobin alpha 2 (HBA2). Normal human fetal liver tissues were homogenized, and human liver nuclear proteins were isolated by centrifugation. The total human fetal liver nuclear proteins were used to immunize BALB/c mice for preparing McAbs by hybridoma technique. The McAbs specificity was identified by ELISA, Western blot, and immunohistochemistry. The antigen was identified by Uni-ZAP expression library screening. The results showed that one hybridoma cell line, AEE091, secreting specific McAb against HBA2 was established. The Ig subclass of this McAb was IgG1 (kappa). Data from immunohistochemistry assay showed that AEE091 could recognize human liver nuclear protein. Using AEE091 McAb, isolation of the protein antigen by IP revealed that AEE091 McAb could recognize 15 kD protein. Screening the Uni-ZAP XR pre-made liver cDNA library with AEE091 hybridoma cell supernatants demonstrated that AEE091 McAb specially reacted with HBA2. It is concluded that a hybridoma cell line stably secreting specific McAb against HBA2 is established. The specific McAb against HBA2 would be very useful for studying HBA2 function and screening thalassemia.

[Preparation and identification of monoclonal antibody against UGP2].

The study was aimed to generate monoclonal antibodies (mAbs) against homo sapiens UDP-glucose pyrophosphorylase 2 (UGP2). Normal human liver tissues homogenized, and cytosolic proteins isolated by centrifugation were used to immunize BALB/c mice to generate mAbs by hybridoma technique. The mAbs were identified by ELISA, Western blot, and immunohistochemistry assay. The antibody specificity was confirmed by Uni-ZAP expression library screening. The results indicated that one hybridoma BAD062 secreting specific mAb against UGP2 was established. The Ig subclass of this mAb was IgG(2b) (kappa), and it could be used in ELISA, Western blot, immunohistochemistry assay. The antigen recognized by BAD062 mAb was localized in the hepatocyte cytoplasm, with molecular weight of 56 kD in the cytosolic proteins of human liver tissue. The BAD062 mAb was further confirmed by immunoscreening of Uni-ZAP XR liver cDNA expression library. It is concluded that a hybridoma cell line stably secretes specific mAb against UGP2. This mAb reacted with UGP2 in ELISA, Western blot, immunohistochemistry assay, and would be very useful for the UGP2 studies.