Clinical significance of circulating tumor cells via combined whole exome sequencing in early stage cancer screening: A case report.

A newly-developed platform, integrating subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH), was applied to analyze the clinical significance of circulating tumor cells (CTCs) for early screening of cancer in healthy people. The present case report describes one healthy individual who accepted a CTC peripheral blood test, and 8 CTCs/7.5 ml blood were detected. However, various conventional cancer biomarkers were all negative, including cervical cytological inspection, alpha-fetoprotein, cancer antigen (CA)-125, CA19-9, carcinoembryonic antigen (CEA), CA15-3 and human papilloma virus. To explore the origin of the CTCs, whole exome sequencing was used to analyze the CTC variation spectrum. A total of 42 mutations were associated with cancer according to analysis in COSMIC (http://cancer.sanger.ac.uk/cosmic). The results revealed a high risk of tumor in the colorectum, stomach and breast (13, 12 and 6 variations matched, respectively). In this individual, an intestinal polyp was discovered and removed by colonoscopy. The intestinal polyp was identified to be a hyperplastic polyp by pathological diagnosis. No lesions were discovered in the stomach and breast. No CTCs were detected in this patient's blood at 1 and 6 months after removal of the lesions. This case indicates that CTC detection by SE-iFISH has potential in early stage cancer screening, and the mutation spectrum of CTC assists the tracking of its sources.

Osteopenia is associated with glycemic levels and blood pressure in Chinese postmenopausal women: a cross-sectional study.

The aim of present study was to explore the relationships between osteopenia and dyslipidemia, glycemic levels or blood pressure in postmenopausal Chinese women. A total of 4080 women aged 42-85 years were enrolled in this cross-sectional study, which was nested in an ongoing longitudinal (REACTION) study. Calcaneus quantitative ultrasound (QUS) was performed and QUS T score was calculated to assess bone mineral density. Osteopenia was defined as a T score ≤-1.0. The relationship between osteopenia and dyslipidemia, glycemic levels or blood pressure was investigated. The prevalence of osteopenia was significantly lower in subjects with systolic blood pressure (SBP) ≥140 mmHg, fasting blood glucose (FBG) ≥8.0 mmol/L, postprandial blood glucose (PBG) ≥15.0 mmol/L, hemoglobin A1c (HbA1C) 6.5-7.5 %, HbA1C ≥7.5 %. These relationships remained significant after controlling for multiple factors. Moreover, significant trend between osteopenia and SBP, FBG, PBG and HbA1C was observed in women. In contrast, no significant associations between osteopenia and diastolic blood pressure (DBP), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) were found, and no significant trend relationship between osteopenia and DBP, TC, TG, HDL-C, LDL-C was found in postmenopausal Chinese women. The present study showed a relationship between SBP, FBG, PBG, HbA1C and osteopenia in postmenopausal Chinese women, while no significant relationship was observed between dyslipidemia, DBP and osteopenia, even after controlling for multiple confounding factors.

Role of Gonadotropin-releasing Hormone Stimulation Test in Diagnosing Gonadotropin Deficiency in Both Males and Females with Delayed Puberty.

BACKGROUND: Delayed puberty can result either from constitutional delay of growth and puberty (CDP) or idiopathic hypogonadotropic hypogonadism (IHH). Gonadotropin-releasing hormone (GnRH) stimulation test has been generally accepted as a current method for diagnosing delayed puberty. The objective of this research was to assess the cut-off values and the efficacy of GnRH stimulation test in the diagnosis of delayed puberty in both males and females. METHODS: A study of 91 IHH, 27 CDP patients, 6 prepubertal children, and 20 pubertal adults was undertaken. Blood samples were obtained at 0, 30, 60, and 120 min after GnRH administration and the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. For each parameter, the sensitivities and specificities were estimated, and the receiver operating characteristic (ROC) curves were constructed. RESULTS: The ROC curves indicated that a serum basal LH <0.6 IU/L or peak LH <9.74 IU/L resulted in moderate sensitivity (73.8% or 80.0%) and specificity (90.9% or 86.4%) in the diagnosis of HH in males. Serum basal LH <0.85 IU/L or basal FSH <2.43 IU/L resulted in moderate sensitivity (80.0% or 100.0%) and specificity (75.0% or 50.0%) in the diagnosis of HH in females. CONCLUSIONS: Our data suggest that isolated use of the gonadorelin stimulation test is almost sufficient to discriminate between HH and CDP in males, but unnecessary in females. The most useful predictor is serum basal or peak LH to differentiate these two disorders in males, but serum basal LH or FSH in females.

Generation of scFv specific to human VEGFR-3 from the neutralizing mAb BDD073.

In our previous study, we have produced a neutralizing mAb of vascular endothelial growth factor receptor 3 (VEGFR-3), specifically BDD073, which could inhibit angiogenesis in the CAM model. However, the clinical application of BDD073 is restricted due to its mouse origin, which might cause human anti-mouse antibody reactions. Herein, we generated functional recombinant single-chain variable fragments (scFv) from mAb BDD073 producing mouse hybridoma cells. The scFv gene containing variable regions of heavy and light chains of BDD073 was cloned into an expression vector with trx tag and expressed in Escherichia coli BL21 (DE3). The recombinant scFv was purified and refolded with Ni-NTA agarose metal affinity column. The bacterially expressed scFv showed moderate potency and specificity to the human VEGFR-3. It may serve as a potential candidate of anti-VEGFR3 treatment for biotechnological and therapeutic applications.

Waist-to-hip ratio, dyslipidemia, glycemic levels, blood pressure and depressive symptoms among diabetic and non-diabetic Chinese women: a cross-sectional study.

OBJECTIVES: To explore the relationship between depressive symptoms and waist-to-hip ratio, dyslipidemia, glycemic levels or blood pressure among diabetic and non-diabetic Chinese women. METHODS: 11,908 women aged ≥40 years were enrolled in this cross-sectional study, including 2,511 with type 2 diabetes and 9,397 without. Depressive symptoms (defined as having mild-to-severe depressive symptoms) were assessed by the Patient Health Questionnaire-9 (PHQ-9) diagnostic algorithm. The prevalence and the odds ratios (ORs) with 95% confidence intervals (CIs) for having depressive symptoms were estimated using logistic regression analysis. RESULTS: The age-adjusted prevalence of depressive symptoms was significantly higher in non-diabetic subjects with waist-to-hip ratio (WHR) ≥0.9 (8.6%, age-adjusted OR 1.51 [95% CI 1.17, 1.95]), total cholesterol (TC)>6.22 mmol/L (8.8%, 1.58 [1.16, 2.15]), and Hemoglobin A1c (HbA1c) ≥6.00 mmol/L (7.7%, 1.69 [1.34, 2.14]), while it was significantly lower in non-diabetic subjects with diastolic blood pressure (DBP) between 80 to 89 mmHg (6.2%, 0.78 [0.64, 0.95]). These relationships remained significant even after controlling for multiple factors (WHR ≥0.9: multivariable-adjusted OR 1.39 [95% CI 1.07, 1.80]; TC>6.22 mmol/L: 1.56 [1.14, 2.12]; HbA1c ≥6.00 mmol/L: 1.64 [1.30, 2.08]; DBP 80-89 mmHg: 0.78 [0.64, 0.95]). However, no significant trend between depressive symptoms and WHC, TC, HbA1c, DBP was observed in diabetic women, and no significant trend relationship between depressive symptoms and BMI, WC, TG, or SBP was observed in both non-diabetic and diabetic women. Moreover, the prevalence of depressive symptoms was significantly higher in previously-diagnosed diabetes, compared with non-diabetic subjects, while no significant differences were observed between newly-diagnosed diabetes and non-diabetic subjects. CONCLUSION: The present study showed a relationship between WHR, TC, HbA1c, DBP and depressive symptoms among non-diabetic women, while no significant relationship between them was observed among diabetic women, even after controlling for multiple confounding factors.

[The relationship between calcaneus bone mineral density and metabolic syndrome].

OBJECTIVE: To evaluate the association between calcaneus bone mineral density (BMD) and metabolic syndrome (MS). METHODS: A cross-sectional study was carried out in 5 552 subjects with 1 987 men and 3 565 women (age:40-87 years old). MS was defined according to Chinese Diabetes Society criteria. BMD was assessed by quantitative ultrasound. RESULTS: The proportion of MS was 29.0% in male and 24.4% in female. There were no differences in BMD between MS and non-MS subjects in both genders. Linear trend analysis displayed that BMD was positively associated with the increase of MS components in post-menopausal women after adjustment of age, ALT, creatinine and exercises (P < 0.05). Moreover, multiple regression analysis showed that BMD was inversely correlated with age (ß = -0.034, P < 0.001) and positively correlated with BMI (ß = 0.046, P = 0.001) , TG (ß = 0.066, P = 0.034) and systolic blood pressure (SBP) (ß = 0.007, P = 0.039) in post-menopausal women with MS. CONCLUSIONS: BMD tended to increase with the numbers of MS components in post-menopausal women. It was positively correlated with BMI, TG and SBP in postmenopausal women with MS.

Inhibition of angiogenesis by a novel neutralizing antibody targeting human VEGFR-3.

Vascular endothelial growth factor receptor 3 (VEGFR-3) is a receptor for the vascular endothelial growth factor C and D (VEGF-C and D) and plays a critical role in the development of embryonic vascular system and regulation of tumor lymphangiogenesis. In this report, we generated a novel panel of 17 monoclonal antibodies (mAbs) against human VEGFR-3 and determined their ability to inhibit the proliferation of human erythroleukemia (HEL) cells and angiogenesis of chick embryo chorioallantoic membrane (CAM). Among these mAbs, BDD073 was demonstrated to inhibit the interaction of soluble VEGFR-3 with VEGF-D and the proliferation of HEL cells. Furthermore, in chick embryo CAM angiogenesis experiments, the angiogenesis induced by recombinant glutathione-S-transferase-VEGF-D was decreased in the presence of antibody BDD073. These data suggest that this novel neutralizing antibody against human VEGFR-3 could be a tool for the investigations into the biology of VEGFR-3, and potentially a reagent for blocking VEGF-D-induced angiogenesis and lymphogenesis.

Cloning and characterization of SCIRR69: a novel transcriptional factor belonging to the CREB/ATF family.

The complete cDNA sequence of a novel gene, SCIRR69 (spinal cord injury and regeneration related no. 69 gene), was obtained by RACE technique. It codes for a protein of 521 amino acid residues homologous to human CREB3l2 (also known as BBF2H7) and mouse CREB3l2. The protein contains a basic DNA binding and leucine zipper dimerization (B-ZIP) motif and a hydrophobic region representing a putative transmembrane domain, similar to the structure of other CREB/ATF transcription factors. Monoclonal antibody against SCIRR69 was developed and could recognize the SCIRR69 protein in both native and denatured forms. Constructing of SCIRR69 fusion proteins with the GAL4 DNA-binding domain disclosed that SCIRR69 functioned as a transcriptional activator and its N-terminal 60 amino acids accounted for the activation ability. SCIRR69 resides in the cytoplasm of primary neurons, whereas neuron damage by incision led to the cleavage and translocation from the cytoplasm to the nucleus. These results suggest that SCIRR69 is activated by proteolytic cleavage at the transmembrane domain in response to neuron damage and its amino-terminal cytoplasmic domain translocates into the nucleus to activate the transcription of target genes.

[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.

Antigenically dominant proteins within the human liver mitochondrial proteome identified by monoclonal antibodies.

Analysis of the mitochondrial proteome would provide valuable insight into the function of this important organelle, which plays key roles in energy metabolism, apoptosis, free radical production, thermogenesis, and calcium signaling. It could also increase our understanding about the mechanisms that promote mitochondrial disease. To identify proteins that are antigenically dominant in human liver mitochondria, we generated >240 hybridoma cell lines from native mitochondrial proteins after cell fusion, screening, and cloning. Antibodies that recognized mitochondrial proteins were identified by screening human liver cDNA expression libraries. In this study, we identified 6 major antigens that were recognized by at least 2 different monoclonal antibodies (mAbs). The proteins that were antigenically dominant were: acetyl-Coenzyme A acyltransferase 2 (mitochondrial 3-oxoacyl-Coenzyme A thiolase), aldehyde dehydrogenase 1 family member A1, carbamoyl phosphate synthetase 1, dihydrolipoamide S-acetyltransferase (E2 component of pyruvate dehydrogenase complex), enoyl coenzyme A hydratase 1, and hydroxysteroid (11-beta) dehydrogenase 1. We also determined the subcellular localizations of these enzymes within the mitochondria using immunohistocytochemistry. We believe that these well-characterized antibodies will provide a valuable resource for the Human Liver Proteome Project (HLPP), and will make studies aimed at investigating liver mitochondrial function far easier to perform in future. Our results provide strong evidence that, (i) depletion of dominant proteins from liver mitochondrial samples is possible and, (ii) the approaches adopted in this study can be used to explore or validate protein-protein interactions in this important organelle.

High-throughput antibody generation using multiplexed immunization and immunogen array analysis.

In this work, the authors developed a new screening approach using multiplexed immunization and immunogen array analysis to improve the efficiency of antibody screening for high-throughput antibody generation. The immunogen array is based on a 96-well format in which different immunogens and negative as well as positive controls are immobilized in each well, thus making it possible to screen hundreds of antibody candidates simultaneously. To demonstrate this approach, a model of 4 mixed immunogens immunization was employed. In total, 675 antibody candidates were screened before and after established antibody hybridomas in parallel with immunogen arrays and enzyme-linked immunosorbent assay. The signal intensity, specificity, and cross-reactivity of produced antibody candidates were analyzed using a hierarchical cluster algorithm to track the characteristics of antibody candidates during antibody generation, which might reduce the number of false-positive and false-negative binding of antibodies. Moreover, 4 monoclonal antibodies that were produced successfully recognized their corresponding target antigens.

Structure of oxalacetate acetylhydrolase, a virulence factor of the chestnut blight fungus.

Oxalacetate acetylhydrolase (OAH), a member of the phosphoenolpyruvate mutase/isocitrate lyase superfamily, catalyzes the hydrolysis of oxalacetate to oxalic acid and acetate. This study shows that knock-out of the oah gene in Cryphonectria parasitica, the chestnut blight fungus, reduces the ability of the fungus to form cankers on chestnut trees, suggesting that OAH plays a key role in virulence. OAH was produced in Escherichia coli and purified, and its catalytic rates were determined. Oxalacetate is the main OAH substrate, but the enzyme also acts as a lyase of (2R,3S)-dimethyl malate with approximately 1000-fold lower efficacy. The crystal structure of OAH was determined alone, in complex with a mechanism-based inhibitor, 3,3-difluorooxalacetate (DFOA), and in complex with the reaction product, oxalate, to a resolution limit of 1.30, 1.55, and 1.65 A, respectively. OAH assembles into a dimer of dimers with each subunit exhibiting an (alpha/beta)(8) barrel fold and each pair swapping the 8th alpha-helix. An active site "gating loop" exhibits conformational disorder in the ligand-free structure. To obtain the structures of the OAH.ligand complexes, the ligand-free OAH crystals were soaked briefly with DFOA or oxalacetate. DFOA binding leads to ordering of the gating loop in a conformation that sequesters the ligand from the solvent. DFOA binds in a gem-diol form analogous to the oxalacetate intermediate/transition state. Oxalate binds in a planar conformation, but the gating loop is largely disordered. Comparison between the OAH structure and that of the closely related enzyme, 2,3-dimethylmalate lyase, suggests potential determinants of substrate preference.

[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.

A single Argonaute gene is required for induction of RNA silencing antiviral defense and promotes viral RNA recombination.

Dicer gene dcl2, required for the RNA silencing antiviral defense response in the chestnut blight fungus Cryphonectria parasitica, is inducible upon mycovirus infection and promotes viral RNA recombination. We now report that the antiviral defense response requires only one of the four C. parasitica Argonaute-like protein genes, agl2. The agl2 gene is required for the virus-induced increase in dcl2 transcript accumulation. Agl2 and dcl2 transcripts accumulated to much higher levels in response to hairpin RNA production or infection by a mutant CHV1-EP713 hypovirus lacking the suppressor of RNA silencing p29 than to wild-type CHV1-EP713. Similar results were obtained for an agl2-promoter/EGFP-reporter construct, indicating that p29-mediated repression of agl2 transcript accumulation is promoter-dependent. Significantly, the agl2 deletion mutant exhibited stable maintenance of non-viral sequences in recombinant hypovirus RNA virus vectors and the absence of hypovirus-defective interfering (DI) RNA production. These results establish a key role for an Argonaute gene in the induction of an RNA silencing antiviral defense response and the promotion of viral RNA recombination. They also provide evidence for a mechanism by which a virus-encoded RNA silencing suppressor represses the transcriptional induction of an RNA silencing component.

Generation and characterization of novel human IRAS monoclonal antibodies.

Imidazoline receptors were first proposed by Bousquet et al., when they studied antihypertensive effect of clonidine. A strong candidate for I1R, known as imidazoline receptor antisera-selected protein (IRAS), has been cloned from human hippocampus. We reported that IRAS mediated agmatine-induced inhibition of opioid dependence in morphine-dependent cells. To elucidate the functional and structure properties of I1R, we developed the newly monoclonal antibody against the N-terminal hIRAS region including the PX domain (10-120aa) through immunization of BALB/c mice with the NusA-IRAS fusion protein containing an IRAS N-terminal (10-120aa). Stable hybridoma cell lines were established and monoclonal antibodies specifically recognized full-length IRAS proteins in their native state by immunoblotting and immunoprecipitation. Monoclonal antibodies stained in a predominantly punctate cytoplasmic pattern when applied to IRAS-transfected HEK293 cells by indirect immunofluorescence assays and demonstrated excellent reactivity in flow immunocytometry. These monoclonal antibodies will provide powerful reagents for the further investigation of hIRAS protein functions.

Liver sinusoidal endothelial cell lectin, LSECtin, negatively regulates hepatic T-cell immune response.

BACKGROUND & AIMS: The liver is an organ with paradoxic immunologic properties and is known for its tolerant microenvironment, which holds important implications for hepatic diseases. The molecular basis for this local immune suppression, however, is poorly understood. In this study, we aimed to determine the role of liver sinusoidal endothelial cell lectin (LSECtin), a recently identified member of the dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) family, in the regulation of hepatic T-cell immune response. METHODS: The regulation of T-cell effector function by LSECtin was determined by co-stimulated T cells with anti-CD3/CD28 monoclonal antibody and LSECtin protein, or co-culture of T-cell receptor transgenic T cells with mouse LSECs in vitro. We generated LSECtin knockout mice and prepared recombinant LSECtin protein and complementary DNA plasmids to analyze the role of LSECtin in hepatic T-cell immune regulation in vivo. RESULTS: We showed that LSECtin specifically recognized activated T cells and negatively regulated their immune responses. In mice with T-cell-mediated acute liver injury, the lack of LSECtin accelerated the disease owing to an increased T-cell immune response, whereas the exogenous administration of recombinant LSECtin protein or plasmid ameliorated the disease via down-regulation of T-cell immunity. CONCLUSIONS: Our results reveal that LSECtin is a novel regulator of T cells and expose a crucial mechanism for hepatic T-cell immune suppression, perhaps opening up a new approach for treatment of inflammatory diseases in the liver.

[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.

Hypovirus-responsive transcription factor gene pro1 of the chestnut blight fungus Cryphonectria parasitica is required for female fertility, asexual spore development, and stable maintenance of hypovirus infection.

We report characterization of the gene encoding putative transcription factor PRO1, identified in transcriptional profiling studies as being downregulated in the chestnut blight fungus Cryphonectria parasitica in response to infection by virulence-attenuating hypoviruses. Sequence analysis confirmed that pro1 encodes a Zn(II)(2)Cys(6) binuclear cluster DNA binding protein with significant sequence similarity to the pro1 gene product that controls fruiting body development in Sordaria macrospora. Targeted disruption of the C. parasitica pro1 gene resulted in two phenotypic changes that also accompany hypovirus infection, a significant reduction in asexual sporulation that could be reversed by exposure to high light intensity, and loss of female fertility. The pro1 disruption mutant, however, retained full virulence. Although hypovirus CHV1-EP713 infection was established in the pro1 disruption mutant, infected colonies continually produced virus-free sectors, suggesting that PRO1 is required for stable maintenance of hypovirus infection. These results complement the recent characterization of the hypovirus-responsive homologue of the Saccharomyces cerevisiae Ste12 C(2)H(2) zinc finger transcription factor gene, cpst12, which was shown to be required for C. parasitica female fertility and virulence.

[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.