Development of novel-nanobody-based lateral-flow immunochromatographic strip test for rapid detection of recombinant human interferon a2b

Recombinant human interferon a2b(rhIFNa2b)is widely used as an antiviral therapy agent for the treatment of hepatitis B and hepatitis C.The current identification test for rhIFNa2b is complex.In this study,an anti-rhIFNa2b nanobody was discovered and used for the development of a rapid lateral flow strip for the identification of rhIFNa2b.RhIFNa2b was used to immunize an alpaca,which established a phage nanobody library.After five steps of enrichment,the nanobody I22,which specifically bound rhIFNa2b,was isolated and inserted into the prokaryotic expression vector pET28a.After subsequent purification,the physicochemical properties of the nanobody were determined.A semiquantitative detection and rapid identification assay of rhIFNa2b was developed using this novel nanobody.To develop a rapid test,the nanobody I22 was coupled with a colloidal gold to produce lateral-flow test strips.The developed rhIFNa2b detection assay had a limit of detection of 1 mg/mL.The isolation of I22 and successful construction of a lateral-flow immunochromatographic test strip demonstrated the feasibility of performing ligand-binding assays on a lateral-flow test strip using recombinant protein products.The principle of this novel assay is generally applicable for the rapid testing of other commercial products,with a great potential for routine use in detecting counterfeit recombinant protein products.

SYNTHESIS OF INTERFERON-α_A MONOCLONAL ANTIBODY PACKING MATERIAL IN HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY AND PURIFICATION OF RECOMBINANT HUMAN INTERFERON-α_A

A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.

PURIFICATION OF RECOMBINANT HUMAN INTERFERON-γ BY IMMUNOAFFINITY CHROMATOGRAPHY WITH MONOCLONAL ANTIBODY

E.coli cells expressing recombinant human interferon-γ was disrupted by sonication anddissolved in 7mol·L-1 guanidine hydrochloride.The extract obtained was then renaturated by 70 folddilution with PBS.HulFN γ was purified by affinity chromatography with monoclonal antibody fromthe renaturated crude feed solution.After washing the column with PBS,the adsorbed HulFN γ waseluted with PBS containing 0.5mol·L-1 NaCl.The column was regenerated with 2mol·L-1 GuHClfor reuse.After one step of affinity purification the purity of interferon-γ was over 95%.and thespecific activity of the HulFN-γ reached 1.2×107 IU·mg-1 protein.92.8% of recovery was obtainedin the elution step.Total recovery of HulFN γ activity in the affinity chromatography was 78%.

Neuronal changes in the retinal ganglion cell layer following recombinant human interleukin-2 intravitreal injection in a rat model of chronically elevated intraocular pressure

Intraperitoneal injection of recombinant human interleukin-2（rhIL-2）inhibits neuronal apoptosis in the chronic ocular hypertension retinal ganglion cell layer.Intravitreous injection was performed on retinal ganglion cells in a Wistar rat model of chronically elevated intraocular pressure to observe the effects of LY294002 and AG490 on retinal ganglion cell survival,macrophage activation,and PI3K/Akt and JAK/STAT activation.The number of retinal ganglion cells in the rhIL-2 treatment group was much greater than in the normal control and phosphate-buffered saline groups.Western blot analysis revealed low Akt and STAT3 protein expression in the retina after 3-hour intravitreous injections of rhIL-2.However,protein expression was increased at 12 hours,but decreased again at 24 hours,with very low expression at 96 hours.LY294002 and AG490,which are inhibitors of the PI3K/Akt and JAK/STAT3 signal pathways,prevented upregulation of Akt and STAT3 protein expression in the retina,respectively.Intravitreous injection of rhIL-2 exhibited neuroprotective effects by decreasing retinal ganglion cell layer damage in a rat model of chronic glaucoma.These results suggest that intravitreal injection of rhIL-2 could induce the PI3K/Akt and JAK/STAT3 signaling pathways to protect retinal ganglion cells in chronically elevated intraocular pressure models.

CORAL AS A CARRIER FOR RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2

By combining coral with recombinant human bone morphogenetic protein-2 (rhBMP-2), rhBMP-2/coral composite was obtained in this study. Following implantation of the composite into the muscle pouches of mice, cartilage growth was induced in the pores or on the surface of the implants at one week, woven bone at three week and lamellar bone with bone marrow at six week, and coral was absorbed partially. The induced formation of endochondral bone was time-related and rhBMP-2 dose-related. The results of this study indicate that the composite possesses a superior ability of osteogenesis, and coral acts as one of the most suitable rhBMP-2 slowrelease carriers currently available. The composite will be a new type of bone substitute to be used in orthopaedics and maxillofacial surgery.

Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

Expression of Human Interferon α 2b Gene in Ginseng Cells

The human interferon α 2b（hIFN-α2b） gene was cloned into binary vector pBI121 to obtain plant expression vector pBIFN. The recombinant plasmid pBIFN was transferred into Agrobacterium tumefaciens strain LBA4404. Then the hIFN-α2b gene was introduced into ginseng callus cells via Agrobacterium-mediated transformation and the ginseng cell line carrying hIFN-α2b gene was selected on G418-containing medium. The presence of target gene in transformed cells was confirmed by PCR and RT-PCR. The results indicate that hIFN-α2b gene has been integrated into the ginseng cells＇ genome, with transcription products, hIFN-α2b expressed by the transgenic ginseng cells was detected by Western blot. It was shown that a specific protein band at 19000 could be observed. Cytopathic effect（CPE） inhibition assay using the W1SH-VSV system shows that the mean antiviral activity of expressed hlFN-a2α was 6.0× 10^4 IU/mL.

The Concept Study of Recombinant Human Soluble Thrombomodulin in Patients with Acute Respiratory Distress Syndrome

Background: Recombinant human soluble thrombomodulin (rhTM) was approved for the treatment of disseminated intravascular coagulation in Japan, and rhTM has anti-inflammatory effects. Disordered coagulation is a part of the acute respiratory distress syndrome (ARDS) pathophysiology and thus we hypothesize that anticoagulant therapy may help. This preliminary study was to observe the safety of rhTM administration and the improvement on biomarker levels after the therapy for ARDS-patients. Objectives: Case series of ARDS-patients. Methods: Seventeen ARDS-patients that required ventilatory management were treated with rhTM and clinical and laboratory data were collected including platelets, thrombin-antithrombin complex (TAT), fibrinogen degradation products, oxygen saturation/the fraction of inspired oxygen (SpO2/FIO2), and high-mobility group-1 (HMG-1). The administration of rhTM was started during 6 days at a bolus dose of 0.06 mg/kg/day immediately after the diagnosis of ARDS. Results: Eleven of the 17 ARDS-patients were alive at 28 days after the beginning of the administration of rhTM. The serial pattern of the SpO2/FIO2 showed remarkable differences between the survivors and nonsurvivors from day 5 to day 7. The TAT in the survivors significantly decreased after treatment, and there were significantly lower levels in the TAT on day 7 in comparison to that of the nonsurvivors. The serial changes of HMG-1 showed increased levels in the nonsurvivors until day 5 after the administration of rhTM. Conclusions: Additional rhTM administration can safely improve the parameters in survival ARDS-patients, as demonstrated by significant improvements in the SpO2/FIO2, HMG-1 and TAT.

CLONING AND SEQUENCING OF MATURE FRAGMENT OF HUMAN BMP4 GENE

Objective To study the cloning and sequencing of mature fragment of human bone morphogenetic protein 4 gene. Methods The template DNA was obtained from the human osteosarcoma cell line U2OS. By using RT PCR method, the cDNA coding for the mature fragment of BMP 4 was amplified, cloned into the vector pUC19, and sequenced by Sanger Dideoxy mediated Chain Termination method. Results The mature fragment of BMP4 cDNA was obtained by RT PCR and determined by sequencing. Through the computer search on Genebank, the analysis showed that the homology of nucleotides and amino acids between cDNA of rhBMP4 mature fragment of this study and the published sequence was 99%. Sequence analysis showed that there were two differences, one was at base 1154(201): G→C, which had no influence on the corresponding amino acids(Val). Another was at base1222(269):C→T, the mutation at the base 1222 had the change of Ala to Val. Conclusion The mature fragment of BMP4 gene has been cloned. The results will be of great significance in treatment of skeletal injuries and diseases.

Expression and Significance of SHP-2 in Human Papillomavirus Infected Cervical Cancer

This study investigated the expression and prognostic value of SHP-2 in cervical cancer caused by human papillomavirus (HPV) infection. Forty-five specimens from patients with cervical cancer (stageⅠ-Ⅲ), 32 specimens from patients with cervical intraepithelial neoplasia (CIN) (Ⅰ, Ⅱ) and 20 normal cervical samples from patients with hysteromyoma were collected in Department of Pathology for comparison. The expression levels of SHP-2 and IFN-β proteins were detected by using immunohistochemistry. The mRNA expression level of SHP-2 was detected by using quantitative real-time polymerase chain reaction (PCR). HPVs were detected by HPV GenoArray Test. The Spearman correlation was used to compare the expression level of SHP-2 in HPV infected cervical cancer vs non-HPV infected normal cervix. The level of SHP-2 protein expression in the cancer tissues (88.8%) was significantly higher than in CIN tissues (62.5%) and normal cervixes (45%) (P<0.05 and P<0.05, respectively). The SHP-2 mRNA levels in the cancer tissues were upregulated as compared with those in the normal cervixes (P<0.05). Twenty-one (46.7%) cervical cancers, 25 (78.1%) CINs and 17 (85%) normal cervixes showed IFN-β positive staining in cytoplasm. There was statistically significant difference in the expression rate of IFN-β between cervical cancer and normal cervix (χ2=8.378, P<0.05) as well as between cervical cancer and CIN (χ2=7.695, P<0.05). HPV16/18 infections could be found in normal cervixs (15%), CINs (68.7%) and cervical cancers (84.4%). There was a correlation between HPV infection and SHP-2 expression in cervical cancer (rs=0.653, P<0.05). SHP-2 may be a useful prognostic and diagnostic indicator for HPV infected cervical cancer. In cervical cancers, SHP-2 mRNA and protein overexpression was associated with IFN-β lower-expression.

Transepithelial transport of putrescine across monolayers of the human intestinal epithelial cell line, Caco-2

AIM: To study the transepithelial transport characteristics of the polyamine putrescine in human intestinal Caco-2 cell monolayers to elucidate the mechanisms of the putrescine intestinal absorption. METHODS: The transepithelial transport and the cellular accumulation of putrescine was measured using Caco-2 cell monolayers grown on permeable filters. RESULTS: Transepithelial transport of putrescine in physiological concentrations (】 0.5 mM) from the apical to basolateral side was linear. Intracellular accumulation of putrescine was higher in confluent than in fully differentiated Caco-2 cells, but still negligible (less than 0.5%) of the overall transport across the monolayers in apical to basolateral direction.EGF enhanced putrescine accumulation in Caco-2 cells by four fold, as well as putrescine conversion to spermidine and spermine by enhancing the activity of S adenosylmethionine decarboxylase. However, EGF did not have any significant influence on putrescine flux across the Caco-2 cell monolayers. Excretion of putrescine from Caco-2 cells into the basolateral medium did not exceed 50 picomoles, while putrescine passive flux from the apical to the basolateral chamber, contributed hundreds of micromoles polyamines to the basolateral chamber. CONCLUSION :Transepithelial transport of putrescine across Caco2 cell monolayers occurs in passive diffusion, and is not influenced when epithelial cells are stimulated to proliferate by a potent mitogen such as EGF.

Preparation and in vitro studies of microencapsulated cells releasing human tissue inhibitor of metalloproteinase-2

Objective： To prepare microencapsulated cells releasing human tissue inhibitor ofmetalloproteinase-2 （TIMP-2）, and investigate their biological characteristics in vitro. Methods： Chinese hamster ovary （CHO） cells were stably transfected with a human TIMP-2 expression vector, encapsulated in barium alginate microcapsules and cultured in vitro. Morphological appearance of the microcapsules was observed under a light microscope. Cell viability was assessed using MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay. Enzyme linked immunosorbent assay （ELISA） and reverse zymography were used to confirm the release of biologically active TIMP-2 from the microcapsules. Cryopreservation study of the microencapsulated cells was carried out using dimethyl sulfoxide （DMSO） as preservative agent. Results： The microcapsules appeared like a sphere with diameter of 300-600 ~tm. The surface of the capsule wall was clearly smooth. The microencapsulated cells survived well and kept proliferating over the 6 weeks observed. No significant difference in TIMP-2 secretion was found between encapsulated and unencapsulated cells. Reverse zymography confirmed the bioactivity of MMP （matrix metalloproteinase） inhibition of TIMP-2. The cryopreservation process did not damage the microcapsule morphology nor the viability of the cells inside. Conclusion： Microencapsulated engineered CHO cells survive at least 6 weeks after preparation in vitro, and secrete bioactive TIMP-2 freely from the microcapsules.

Ameliorative effects of human adipose tissue-derived mesenchymal stem cells on myelin basic protein-induced experimental autoimmune encephalomyelitis in Lewis rats

Mesenchymal stem cells have been previously shown to exert an immunomodulatory function. The present study sought to investigate the effects of multipotential human adipose tissue-derived mesenchymal stem cells （hAdMSCs） on disease progression and cytokine expression in Lewis rats with experimental autoimmune encephalomyelitis （EAE） induced by myelin basic protein. The duration of EAE paralysis in the group treated on day 7 posfimmunization with 5 × 10^6 hAdMSCs was significantly reduced compared with the vehicle-treated controls and the 1 x 106 hAdMSC- treated group. The duration of EAE paralysis in the groups treated with 5 × 10^6 hAdMSCs on both day 1 and day 7 postimmunization was significantly reduced compared with the vehicle-treated controls and the groups treated with 5 × 10^6 hAdMSCs on both day 7 and day 10 postimmunization. The mRNA expression of interleukin-10 and indoleamine 2, 3-dioxygenase was significantly decreased in the hAdMSC-treated group compared with the vehicle-treated group. These findings suggest that the ameliorative effects of hAdMSCs on EAE symptoms operate in a dose- and time-dependent manner and can be mediated in part by the ample production of anti-inflammatory cytokines.

Expression of mature peptide of human bone morphogenetic protein-2 in Escherichia coli

To express die mature peptide of human bone morphogenetic protein-2 in Escherichia coil. Methods: TheDNA fragment encoding the mature peptide of human bone morphogenetic protein-2 (hBMP-2m) was inserted into expression vectorpDH in which foreign gene was controlled by PRPL promoters. E. coli DH5a transformed with recombinant plasmid pDHB2m wasinduced at 42℃to express the target protein. The expressed product was partially purified and refolded, and then implanted intorat thigh muscles to assay its bone inductive activity. Results: After induction, a protein band on SDS-PAGE gel with an apparentmol. wt. of 13kD was observed to anticipate in the strain carrying pDHB2m, but not in the control. The expressed hBMP-2m accounted for 45%-60% of the total bacterial protein. The expressed product existed in a form of inclusion body. After partially purified and refolded, rhBMP-2m could induce the formation of cartilage and bone tissue heterotopically. Conclusion: The maturepeptide of human bone morphogenetic protein-2 has ben successfully expressed in E. coli and the product has ectopic bone inductive activity.

Reconstruction of orbital defect in rabbits with composite of calcium phosphate cement and recombinant human bone morphogenetic protein-2

Background Calcium phosphate cement （CPC） is a biocompatible and osteoconductive bone substitute, and recombinant human bone morphogenetic protein-2 （rhBMP-2） has strong osteoinductibility, therefore we developed a composite bone substitute with CPC and rhBMP-2 and evaluate its reconstruction effect in rabbit orbital defect.Methods Thirty-six rabbits were randomly divided into two groups and a 5 mmx5 mmx2 mm bone defect in the infraorbital rim was induced by surgery in each orbit （72 orbits in all）. The orbital defects were treated with pure CPC or composite of CPC and rhBMP-2. The osteogenesis ability of different bone substitute was evaluated by gross observation, histological examination, histomorphometrical evaluation, compressive load-to-failure testing, and scanning electron microscope （SEM）.Results Gross observation showed that both bone substitutes were safe and effective for reconstruction of orbital defect. However, histological examination, histomorphometrical evaluation and SEM showed that CPC/rhBMP-2 group had faster speed in new bone formation and degradation of substitute material than CPC group. Compressive load-to-failure testing showed that CPC/rhBMP-2 group had stronger compressive strength than CPC group at every stage with significant difference （P ＜0.05）.Conclusion Composite of CPC/rhBMP-2 is an ideal bioactive material for repairing orbital defect, with good osteoconductibility and osteoinductibility.

The use of recombinant human bone morphogenetic protein-2 （rhBMP-2） in maxillofacial trauma

In recent years, recombinant human bone morphogenetic protein-2 （rhBMP-2） has been introduced as a therapeutic option in the treatment of several congenital and acquired craniofacial defects. Although there have been promising clinical results, the international literature still lacks complete guidelines, including limits and indications for the use of rhBMP-2. The possible indications for rhBMP-2 in patients undergoing facial trauma are discussed in this article.

A Stable Vector for High-Level Expression and Secretion of Human Interferon αA in Yeast

Yeast high stable plasmid vector pHC11 was constructed by introducing pEMBL Yi27 cleaved with SmaI into the SnaBI site of intact 2 μm plasmid. The result of plasmid stability assay revealed that 82% of the host cells still harbored the vector after 50-generations growth in non-selective medium, which confirmed the existence of a non-functional region in 2 μm plasmid. The human interferon αA (IFN αA) gene expression-secretion cassette was inserted into pHC11, and the yeast transformant was cultured in complex medium. Tbe data showed that the expressed product was 36.8% of the total protein amount in the culture supernatant and the IFN αA biological activity was 2.6×10^(10) units per liter, demonstrating that high-level expression and secretion of IFN αA were achieved in yeast by using the stable vector pHC11.

Study on pharmacodynamics of recombinant interferon α-2b suppository

Objective To investigate the antiviral activity of recombinant interferonα-2b suppository(IFNα-2b)in vivo and in vitro.Methods The cytopathic-effect inhibition assay was applied in this study to investigate the antiviral activity of this drug as well as yingtelong and axiluowei as positive control.The guinea pig model of vaginitis and skin infection caused by HSV-2 infection were established,treated with IFNα-2b suppository at dosages of 60000、180000、540000 IU,using IFNα-2b injection 180000 IU·kg-1 as controls.Score the pathological changes of appearance and skin,the virus activities of vaginal secretion and tissue sections of viginae were assayed after treatment.Results The TD50 of IFN α-2b and yingtelong for Vero cells was(>100)μg·mL-1 and(>100000)IU·mL-1,respectively.The IC50 of IFN α-2b and yingtelong and axiluowei for Herpes virus type 1 was(0.29±0.08)μg·mL-1 and(185.0±28.8)IU·mL-1 and(0.19±0.03)μg·mL-1,respectively.The mean scores for vaginal and skin lesion of the treated groups were lower than those of untreated group.Among these concentrations,the IFNα-2b suppository of 540000 IU·kg-1 group.Showed highest anti-viral activity.The virus activity in vaginal secretion of treated group was lower than that of untreated group too(P<0.01 or P<0.05).Tissue sections of viginae after treatment with IFNα-2b suppository showed significantly therapeutical effects on the degrees of vaginal lesion.At the same dosage,The anti-HSV activity of IFNα-2b suppository was also compared with IFNα-2b injection,the results showed that the activity of suppository of 540000 IU·kg-1 group was similar to that of the injection.Conclusions The IFNα-2b suppository has anti-viruses function both in vivo and in vitro.

Study of recombinant human IFN-α-2b bacilli Calmette–Guerin activated killer cells and against bladder cancer cell in vitro

Presently,one of the most potent immunothera-pies is the application of bacillus Calmette Guerin(BCG)to prevent recurrences of the superficial bladder cancer.Despite its successful use,nonresponders and certain side effects remain a major obstacle.Therefore,current studies aim at developing recombinant BCG(rBCG)strains secreting Th1-like cytokines to improve the effectiveness of the therapy.In this study,a new type of rBCG strain constructed by Tianjin institute of Urology was tested for its immunostimulatory capacity in vitro.Peripheral blood monocytes(PBMC)were stimulated by recombinant BCG and transformed into bacilli Calmette–Guerin activated killer(BAK)cells,and the effect of anticancer BAK cells was studied.Recombinant IFN-a-2b-BCG,wild-type BCG(wBCG),wild-type BCG and IFN-a-2b were coincubated with PBMCs respectively in vitro,and the proliferation of PBMC was detected with MTT in different time.BAK cells have the ability to kill bladder tumor cells,and the antitumor activity of effecter cells was determined by LDH release assay.The result of MTT showed that the proli-feration of PBMC in the recombinant BCG group was more powerful than in the other two groups(P<0.05).The result of LDH release assay showed that the antitumor activity of BAK cells stimulated by Recombinant BCG was the highest in all groups.We conclude that the recombinant BCG can activate more PBMCs to anti-bladder cancer in vitro than wild-type BCG does.