Neuroprotective Effect of Granulocyte Colony-stimulating Factor in a Focal Cerebral Ischemic Rat Model with Hyperlipidemia

Granulocyte colony-stimulating factor (G-CSF) has been demonstrated to have neuroprotective effects in rat model with focal cerebral ischemia through anti-apoptotic pathways and by promoting proliferation of neural stem cells. In the present study, we examined the neuroprotective effect of G-CSF in an acute focal cerebral ischemia rat model with lipid metabolism disorder. Eighty male SD rats were randomly divided into normal diet control group (NC group) and high-fat diet group (HFD group) (n = 40 in each). In HFD group, rats were fed on high fat diet to induce atherosclerosis. After 29 days, 4 rats from each group were sacrificed to evaluate the effects of different diets, and the middle cerebral artery occlusion (MCAO) was performed in the rest of the rats. MCAO rats received either G-CSF (50 μg·kg–1·mL–1) or phosphate buffered saline (PBS) injection through the external jugular vein for 5 days, which was followed by 5-bromo-deoxy uridine (BrdU, i.p., 50 mg/kg) injection for another 7 days. To evaluate the effects of G-CSF treatment on neurological function, the modified neurological severity score (mNSS) was calculated. The vascular distribution, ischemic cells proliferation, cell apoptosis and the expression of vascular endothelial growth factor (VEGF) were measured to determine the effects of G-CSF treatment. Our results showed that G-CSF-treated rats had a lower mNSS than PBS-treated rats in both NC group and HFD group. G-CSF injection promoted endothelial cell proliferation and vascular regeneration, and inhibited cell apoptosis. The serum and tissue levels of VEGF were significantly increased after G-CSF treatment. It is concluded that G-CSF exerts its neuroprotective effect in focal cerebral ischemia rats with hyperlipidemia by enhancing angiogenesis, promoting cells proliferation, decreasing cell apoptosis, and increasing local VEGF expression.

CO-EXPRESSION OF MACROPHAGE COLONY-STIMULATING FACTOR WITH ITS RECEPTOR IN HUMAN HEPATOMA CELLS AND ITS POTENTIAL ROLES

Objective: To investigate the potential role of macrophage colony-stimulating factor (M-CSF) and macrophage colony-stimulating factor receptor (M-CSF-R) on the growth of human hepatoma cells. Methods: Specimens of different origin, including tissues of human hepatocellular carcinoma (HCC), human fetal liver (FL) and normal liver (NL), the hepatoma cell lines, as well as the peripheral blood mononuclear cells (PBMC) from patients with HCC or liver metastatic tumor (LMT), were used to detect the expression levels of M-CSF and M-CSF-R by ABC immunohistochemistry staining and reverse transcription polymerase chain reaction methods the expression levels of M-CSF and M-CSF-R. Influence of monoclonal antibody against M-CSF (B5) or M-CSF-R (RE2) on proliferation ability of hepatoma cell linesin vitro was also studied. Results: The results showed that hepatoma tissues produced elevated levels of both M-CSF and M-CSF-R compared with those of fetal liver (P<0.001). The M-CSF/M-CSF-R expression levels of PBMC from hepatoma patients were higher than those of LMT patients (P<0.01,P<0.05) and the normal people (P<0.001). The hepatoma cell lines showed strong positive for M-CSF and M-CSF-R production. Both B5 and RE2 displayed a dose-dependent inhibitory effect on the growth and proliferation of hepatoma cells. Conclusion: The study indicates a co-expression model for M-CSF-R in hepatoma cells, suggesting an involvement of M-CSF/M-CSF-R in growth signaling of those malignant cells. The M-CSF/M-CSF-R seems to function through an autonomy mechanism in human hepatoma.

Preclinical evaluation of herpes simplex virus armed with granulocyte-macrophage colony-stimulating factor in pancreatic carcinoma

AIM: To investigate the therapeutic efficacy and mechanisms of action of oncolytic-herpes-simplex-virus encoding granulocyte-macrophage colony-stimulating factor(HSVGM-CSF) in pancreatic carcinoma.METHODS: Tumor blocks were homogenized in a sterile grinder in saline.The homogenate was injected into the right armpit of each mouse.After vaccination,the mice were randomly assigned into four groups: a control group,a high dose HSVGM-CSFgroup [1 × 107plaque forming units(pfu)/tumor],a medium dose HSVGM-CSF group(5 × 106pfu/tumor) and a low dose HSVGM-CSF group(5 × 105pfu/tumor).After initiation of drug administration,body weights and tumor diameters were measured every 3 d.Fifteen days later,after decapitation of the animal by cervical dislocation,each tumor was isolated,weighed and stored in 10% formaldehyde solution.The drug effectiveness was evaluated according to the weight,volume and relative volume change of each tumor.Furthermore,GM-CSF protein levels in serum were assayed by enzyme-linked immunosorbent assays at 1,2,3 and 4 d after injection of HSVGM-CSF.RESULTS: Injection of the recombinant mouse HSV encoding GM-CSF resulted in a significant reduction in tumor growth compared to the control group,and dosedependent effects were observed: the relative tumor proliferation rates of the low dose,medium dose and high dose groups on 15 d after injection were 45.5%,55.2% and 65.5%,respectively.The inhibition rates of the tumor weights of the low,middle,and high dose groups were 41.4%,46.7% and 50.5%,respectively.Furthermore,the production of GM-CSF was significantly increased in the mice infected with HSVGM-CSF.The increase in the GM-CSF level was more pronounced in the high dose group compared to the other two dose groups.CONCLUSION: Our study provides the first evidence that HSVGM-CSFcould inhibit the growth of pancreatic cancer.The enhanced GM-CSF expression might be responsible for the phenomenon.

Impaired granulocyte-macrophage colony-stimulating factor bioactivity accelerates surgical recurrence in ileal crohn's disease

AIM To examine the relationship between elevated granulocyte-macrophage colony-stimulating factor(GMCSF) auto-antibodies(Ab) level and time to surgical recurrence after initial surgery for Crohn's disease(CD). METHODS We reviewed 412 charts from a clinical database at tertiary academic hospital. Patients included in the study had ileal or ileocolonic CD and surgical resection of small bowel or ileocecal region for management of disease. Serum samples were analyzed for serological assays including GM-CSF cytokine, GM-CSF Ab, ASCA Ig G and Ig A, and genetic markers including SNPs rs2066843, rs2066844, rs2066845, rs2076756 and rs2066847 in NOD2, rs2241880 in ATG16 L1, and rs13361189 in IRGM. Cox proportional-hazards models were used to assess the predictors of surgical recurrence.RESULTS Ninety six percent of patients underwent initial ileocecal resection(ICR) or ileal resection(IR) and subsequently 40% of patients required a second ICR/IR for CD. GMCSF Ab level was elevated at a median of 3.81 mcg/mL. Factors predicting faster time to a second surgery included elevated GM-CSF Ab [hazard ratio(HR) 3.52, 95%CI: 1.45-8.53, P = 0.005] and elevated GM-CSF cytokine(HR = 2.48, 95%CI: 1.31-4.70, P = 0.005). Factors predicting longer duration between first and second surgery included use of Immunomodulators(HR = 0.49, 95%CI: 0.31-0.77, P = 0.002), the interaction effect of low GM-CSF Ab levels and smoking(HR = 0.60, 95%CI: 0.45-0.81, P = 0.001) and the interaction effect of low GM-CSF cytokine levels and ATG16 L1(HR = 0.65, 95%CI: 0.49-0.88, P = 0.006).CONCLUSION GM-CSF bioavailability plays a critical role in maintaining intestinal homeostasis. Decreased bioavailability coupled with the genetic risk markers and/or smoking results in aggressive CD behavior.

Mobilization of Peripheral Blood Stem Cells Using Regimen Combining Docetaxel with Granulocyte Colony-stimulating Factor in Breast Cancer Patients

Objective：To evaluate the effectiveness and safety of the mobilization of peripheral blood hematopoietic stem cells by combining docetaxel with granulocyte colony-stimulating factor（G-CSF） in breast cancer patients.Methods：A total of 57 breast cancer patients were treated with docetaxel 120 mg/m2.When the white blood cell（WBC） count decreased to 1.0×109/L,patients were given G-CSF 5-g/kg daily by subcutaneous injection until the end of apheresis.Peripheral blood mononuclear cells（MNC） were isolated by Cobe Spectra Apheresis System.The percentage of CD34＋ cell was assayed by flow cytometry.Results：At a median 6 of days（range 3-8） after the administration of docetaxel,the median WBC count decreased to 1.08×109/L（range 0.20-2.31）.The median duration of G-CSF mobilization was 3 days（range 2-7）.The MNC collection was conducted 8-12 days（median 10 days） after docetaxel treatment.The median MNC was 5.35×108/kg（range 0.59-14.07）,the median CD34＋ cell count was 2.43×106/kg（range 0.16-16.69）.The CD34＋ cell count was higher than 1.00×106/kg in 47 of 57 cases（82.46%） and higher than 2.00×106/kg in 36 cases（63.16%）.The CD34＋ cell count was higher than 2.00×106/kg in 27 collections（23.68%）.The MNC count and the CD34＋ cell count were correlated with the bottom of WBC after docetaxel chemotherapy（r=0.364,0.502,P=0.005,0.000）.The CD34＋ cell count was correlated with the MNC count（r=0.597,P=0.000）.The mobilization and apheresis were well tolerated in all patients.Mild perioral numbness and numbness of hand or feet were observed in 3 cases.No serious adverse events were reported.Conclusion：Mobilization of peripheral blood hematopoietic stem cell by combining docetaxel with G-CSF was effective and safety in breast cancer patients.

Granulocyte-macrophage colony-stimulating factor protects mice against hepatocellular carcinoma by ameliorating intestinal dysbiosis and attenuating inflammation

BACKGROUND Hepatocellular carcinoma(HCC)is the third leading cause of cancer mortality worldwide.The gut microbiota can help maintain healthy metabolism and immunity.Granulocyte-macrophage colony-stimulating factor(GM-CSF)is a critical factor in promoting health and homeostasis;it promotes intestinal immunity,stimulates bone marrow precursors to generate macrophage colonies,and enhances the antibacterial and antitumor activity of circulating monocytes.As such,GM-CSF may protect against HCC development by regulating immunity as well as intestinal microecology.AIM To investigate the impact of GM-CSF on the gut microbiome and metabolic characteristics of HCC.METHODS Thirty-six male BALB/c nude mice were divided into three groups:Control(n=10),HCC(n=13),and HCC+GM-CSF(GM-CSF overexpression,n=13).We utilized HCC cells to establish orthotopic transplantation tumor models of HCC with normal and over-expressing GM-CSF.Liver injury,immune inflammatory function and intestinal barrier function were evaluated.The fecal microbiome and metabolome were studied using 16S rRNA absolute quantification sequencing and gas chromatography-mass spectrometry.RESULTS GM-CSF overexpression significantly affected the gut microbiome of mice with HCC and resulted in a high abundance of organisms of the genera Roseburia,Blautia and Butyricimonass,along with a significant reduction in Prevotella,Parabacteroides,Anaerotruncus,Streptococcus,Clostridium,and Mucispirillum.Likewise,GM-CSF overexpression resulted in a substantial increase in fecal biotin and oleic acid levels,along with a prominent decrease in the fecal succinic acid,adenosine,fumaric acid,lipoic acid,and maleic acid levels.Correlation analysis revealed that the intestinal microbiota and fecal metabolites induced by GM-CSF were primarily involved in pathways related to reducing the inflammatory response,biotin metabolism,and intestinal barrier dysfunction.CONCLUSION GM-CSF can protect against HCC development by regulating immunity and modulating the abundance of specific intestinal microorganisms and their metabolites.This study provides new insights into the therapeutic approaches for HCC.

Granulocyte colony-stimulating factor-producing hepatocellular carcinoma with abrupt changes

Granulocyte colony-stimulating factor(G-CSF)-producing tumor is one of the rare types of cancer clinically characterized by an elevated fever and white blood cell(WBC) increment. Although G-CSF producing tumors have been reported in several types of cancer including those of the lungs, cervix and bladder, G-CSF producing hepatocellular carcinoma is extremely rare. Here, we report the case of a rapidly growing and poorly differentiated hepatocellular carcinoma producing G-CSF. The patient showed symptoms of continuous high fever, stomach pain and cough, and high serum WBC counts, C-reactive protein(CRP) and G-CSF levels were found in laboratory tests. After a radical hepatectomy, the patient completely recovered from the above symptoms and inflammatory state. The serum levels of G-CSF were reduced to normal levels after radical surgery. An immunohistochemical analysis revealed the overexpression of G-CSF in the cytoplasm of certain hepatocellular carcinoma(HCC) cell. The patient's serum WBC, CRP and G-CSF levels remained within normal levels in the six months after surgery without recurrence. This is the 9^(th) case report of G-CSF producing hepatocellular carcinoma in English literature. We review the clinical characteristics of the G-CSF producing HCC and discuss a possible treatment strategy.

Granulocyte colony-stimulating factor-producing squamous cell carcinoma of the tongue exhibiting characteristic fluorine-18 deoxyglucose accumulation on positron emission tomography–computed tomography: A case report

BACKGROUND Granulocyte colony-stimulating factor(G-CSF)is a cytokine produced in inflammatory environments that induces differentiation and proliferation of neutrophils in bone marrow.We report a rare case of aggressive G-CSFproducing squamous cell carcinoma of the tongue exhibiting fluorine-18 deoxyglucose(FDG)accumulation in primary lesion,metastatic lymph nodes,spleen,and bone marrow on positron emission tomography–computed tomography(PET/CT).CASE SUMMARY We report a 58-year-old female with a rapid enlarged lingual mass with partial necrosis.Blood test results from the initial examination revealed a leukocyte count of 21380/μL.On PET/CT,extensive FDG accumulation was observed in the tongue and bilateral cervical lymph nodes,with elevated FDG accumulation in the spleen and bone marrow although no distant metastases were observed.We performed partial glossectomy and bilateral neck dissection.Immunohistochemical staining with G-CSF antibodies on biopsy specimen and resected samples revealed that both specimens were G-CSF positive.This is a rare case of G-CSF producing tongue carcinoma with elevated FDG accumulation in the spleen and bone marrow.CONCLUSION In patients with the tongue cancer and hyperleukocytosis,where FDG accumulations in the spleen and bone marrow are observed using PET/CT and when these accumulations are not caused by metastasis,G-CSF-producing tumors,with associated poor prognosis,should be considered.

CONSTRUCTION OF EUKARYOTIC EXPRESSION VECTOR WITH GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR GENE

Objective: To construct the eukaryotic expression vector that express human granulocyte-macrophage colony-stimulating factor (hGM-CSF) gene for making highly express in mammalian cells. Methods: Extract totally RNA from the induced human fetal lung (HFL) cell line. HGM-CSF cDNA was obtained by reverse transcription-polymerase chain reaction (RT-PCR), and then directionally subcloned into the HindIII and EcoRI site on the pcDNA3.1 plasmid, which was controlled by the CMV promoter, to form the recombinant expressing vector pcDNA3.1-GM-CSF. Results: The PCR amplification was identified and the sequence was analyzed, the results showed that hGM-CSF was properly inserted into the vector and the sequence was correct.

Granulocyte colony-stimulating factor increases extracellular glutamic acid uptake and suppresses free radicals in an experimental model of amyotrophic lateral sclerosis

Excitatory amino acid toxicity and free radical damage play important roles in amyotrophic lateral sclerosis. Granulocyte colony-stimulating factor （G-CSF） protects nerve cells exposed to high-concentrations of glutamic acid, suggesting positive effects in the treatment of amyotrophic lateral sclerosis. The present study induced in vitro motor neuron injury using glutamic acid excitotoxicity, and the biochemical effects of G-CSF on glutamic acid concentration were determined. In addition, the effects of G-CSF on superoxide dismutase, glutathione peroxidase activity in motor neurons, and malondialdehyde and nitric oxide contents were analyzed. Immunohistochemistry was performed to measure neuronal survival. Results revealed that G-CSF significantly suppressed free radical activity, inhibited excitotoxicity, and reduced apoptosis and loss of motor neurons in the anterior horn of the spinal cord.

DETERMINATION OF SERUM SOLUBLE MACROPHAGE COLONY-STIMULATING FACTOR RECEPTOR LEVELS IN PATIENTS WITH HEMATOLOGICAL DISEASES

Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological diseases. Methods: The concentration of M-CSFsR was determined by ELISA. The serum M-CSFsR was identified and characterized by immunoprecipitation and Western blotting. Results: The mean serum level of M-CSFsR of 123 normal individuals was 0.48 ng/ml ± 0.41 ng/ml. Immunoprecipitation and Western blotting assay revealed a ～ 90kD band of serum M-CSFsR. The mean serum M-CSFsR level of 60 patients with acute lymphoblastic leukemia (ALL), 36 patients with acute myeloblastic leukemia (AML), 13 patients with myelodysplastic syndrome (MDS) and 42 patients with aplastic anemia (AA) .were 0.22 ng/ml±0.23 ng/ml, 0.17 ng/ml±0.16 ng/ml, 0.19 ng/ml±0.16 ng/ml and 0.23 ng/ml±0.21 ng/ml, respectively, which were significantly lower than that of normal subjects (P=0.002 ,P<0.0001,P<0.0001 andP<0.0001). The mean serum M-CSFsR level of 51 idiopathic thrombocytopenic purpura (ITP) patients was significantly higher than that of normal subjects (2.05 ng/ml±2.75 ng/ml,P<0.0001). Conclusion: The serum M-CSFsR levels of patients with ALL, AML, MDS and AA were significantly lower, while the level of patients with ITP was significantly higher than that of normal individuals. Patients with severe ITP (platelet count<30×l09/L) had the highest M-CSFsR level. It suggested that the abnormal levels of serum M-CSFsR may associate with some hematological diseases and may contribute to the pathological process.

Granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells for the treatment of ischemic stroke

Adult, male, Sprague-Dawley rats were injected with granulocyte-macrophage colony-stimulating factor-transfected bone marrow stromal cells （GM-CSF-BMSCs） into the ischemic boundary zone at 24 hours after onset of middle cerebral artery occlusion. Results showed reduced infarct volume, decreased number of apoptotic cells, improved neurological functions, increased angiogenic factor expression, and increased vascular density in the ischemic boundary zone in rats that underwent GM-CSF-BMSCs transplantation compared with the BMSCs group. Experimental findings suggested that GM-CSF-BMSCs could serve as a potential therapeutic strategy for ischemic stroke and are superior to BMSCs alone.

Granulocyte colony-stimulating factor as a novel adjunct to improve hepatitis B vaccination

Hepatitis B vaccination is successful in 95% of individuals. In the remainder, despite repeated attempts, immunization often remains unsuccessful. 'Non-response' leaves the individual susceptible to infection. Various strategies have been employed to overcome this. These include the use of adjuncts alongside conventional vaccines which activate immune responses. In this case report we demonstrate the successful use of the hematopoietic growth factor Granulocyte colonystimulating factor (G-CSF) as a vaccine adjunct in an individual who had previously failed conventional vaccination three times. The patient tolerated the regimen without any side effects and achieved a hepatitis B surface antibody titer greater than 100 IU/L. Use of G-CSF as a vaccine adjunct for hepatitis B has not previously been reported and the outcome in this case suggests that the use of G-CSF in this context warrants further exploration.

Mobilization Efficiency of Granulocyte Colony-stimulating Factor and Stem Cell Factor to Bone Marrow Mononuclear Cells and Mechanisms

The mobilization efficiency of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) to bone marrow mononuclear cells (MNCs) in mice was observed, and the changes of CXCL12/CXCR4 signal were detected in order to find out the mobilization mechanism of stem cells. Kunming mice were randomly divided into two groups. The mice in treatment group were subjected to subcutaneous injection of G-CSF at a dose of 100 μg/kg and SCF at a dose of 25 μg/kg every day for 5 days, and those in control group were given isodose physiological saline. The MNCs were separated, counted and cultured, and the colony-forming unit-fibroblast (CFU-F) was evaluated. CD34+CXCR4+ MNCs were sorted by flow cytometry. The expression of CXCL12 protein in bone marrow extracellular fluid was detected by ELISA, and that of CXCL12 mRNA in bone marrow was measured by RT-PCR. The results showed that the counts of MNCs in peripheral blood and bone marrow were increased after administration of G-CSF/SCF (P<0.01). The factors had a dramatic effect on the expansion capability of CFU-F (P<0.05). Flow cytometric of bone marrow MNCs surface markers revealed that CD34+CXCR4+ cells accounted for 44.6%±8.7% of the total CD34+ MNCs. Moreover, G-CSF/SCF treatment induced a decrease in bone marrow CXCL12 mRNA that closely mirrored the fall in CXCL12 protein. In this study, it is evidenced that G-CSF/SCF can effectively induce MNCs mobilization by disrupting the balance of CXCL12/CXCR4 signaling pathway in the bone marrow and down-regulating the interaction of CXCL12/CXCR4.

Granulocyte colony-stimulating factor promotes growth of processes,growth associated protein 43 and microtubule-associated protein 2 expression in cultured rat retinal ganglion cells in vitro

Following granulocyte colony-stimulating factor （G-CSF） treatment,the growth of processes in cul-tured rat retinal ganglion cells （RGCs） in vitro,expression of growth associated protein 43,and expression of microtubule-associated protein 2 mRNA expression were significantly increased.In contrast,RhoA/Rock protein content was significantly reduced by G-CSF treatment.These results indicate that G-CSF promotes the growth of processes in RGCs and increases the expression of growth-associated protein 43 and microtubule-associated protein 2 mRNA by inhibiting the RhoA/Rock pathway,thereby benefiting axonal repair in RGCs exposed to hypoxia.

Anti-apoptotic effects of recombinant human granulocyte colony-stimulating factor in focal cerebral ischemic rats

The neuroprotective effects of granulocyte colony-stimulating factor in cerebral ischemia/reperfusion injury are currently contentious. The present study examined the effects of subcutaneous injection of recombinant human granulocyte colony-stimulating factor （50 pg/kg） over 5 days in a model of cerebral ischemia/reperfusion with intraluminal filament occlusion in rats. The results indicated that recombinant human granulocyte colony-stimulating factor reduced brain infarct volume following cerebral ischemia/reperfusion injury in rats, down-regulated the expression of caspase-3 mRNA （a key protease for apoptosis in the cerebral ischemia zone）, lowered the rate of neuronal apoptosis in the cerebral ischemia zone, and notably ameliorated neurological function. These results indicate that recombinant human granulocyte colony-stimulating factor has anti-apoptotic effects on neurons following focal cerebral ischemia/reperfusion injury, and exerts neuroprotective effects.

Disseminated carcinomatosis of the bone marrow caused by granulocyte colony-stimulating factor:A case report and review of literature

BACKGROUND Disseminated carcinomatosis of the bone marrow(DCBM)is a widespread metastasis with a hematologic disorder that is mainly caused by gastric cancer.Although it commonly occurs as a manifestation of recurrence long after curative treatment,the precise mechanism of relapse from dormant status remains unclear.Granulocyte colony-stimulating factor(G-CSF)can promote cancer progression and invasion in various cancers.However,the potential of G-CSF to trigger recurrence from a cured malignancy has not been reported.CASE SUMMARY A 55-year-old Japanese woman was diagnosed with Ewing sarcoma localized on the fifth lumbar vertebrae 6 years after curative gastrectomy for T1 gastric cancer.After palliative surgery to release nerve compression,pathological diagnosis of the resected specimen was followed by curative radiation and chemotherapy.During treatment,G-CSF was administered 32 times for severe neutropenia prophylaxis.Eight months after completing definitive treatment,she complained of severe back pain and was diagnosed as multiple bone metastases with DCBM from gastric cancer.Despite palliative chemotherapy,she died of disseminated intravascular coagulation 13 d after the diagnosis.Immunohistochemical examination of the autopsied bone marrow confirmed a diffuse positive staining for the G-CSF receptor(G-CSFR)in the relapsed gastric cancer cell cytoplasm,whereas the primary lesion cancer cells showed negative staining for G-CSFR.In this case,G-CSF administration may have been the key trigger for the disseminated relapse of a dormant gastric cancer.CONCLUSIONWhen administering G-CSF to cancer survivors,recurrence of a preceding cancer should be monitored even after curative treatment.

A New Protocol for Solubilization, Refolding and Purification of Recombinant Human Granulocyte Colony-stimulating Factor in Inclusion Bodies

Recombinant human granulocyte colony-stimulating factor （rhG-CSF） in inclusion bodies was solubilized by 8 mol/L urea solution and subsequently precipitated by acetone to improve its purity. After that, the precipitates were solubilized by sodium hydroxide solution containing 2 mol/L urea. Then the solubilized rhG-CSF was passed through a size exclusion chromatography for refolding and extensive purification, and further purified by a weak anion exchange chromatography. The purity and mass recovery of refolded rhG-CSF were 96.5% and 75.6%, respectively. The bioactivity was 8.4x10^7 IU/mg.

Antiviral Activity of Silkworm Expressed Recombinant Human Macrophage Colony-Stimulating Factor in Vitro and Its Mechanism

Cells, pretreated with the recombinant human macrophage colony-stimulating factor (rhM-CSF) expressed in silkworm larvae, were inoculated with several viruses to observe the effect of rhM-CSF on viral replication. The results showed that in cultures of fibroblast derived from human fetal skin-muslce tissues infected with the viruses (including VSV, rhinovirus, influenza virus type A3, HSV-1, HSV-2, adenovirus type 6 and type 11), rhM-CSF inhibited the virus-induced cytopathy, which defered or relieved the cytophathy and that in the cells derived from breast feeding rabbit kidney infected with HSV-1, rhM-CSF reduced titer of the virus in a rhM-CSF dose-dependent pattern,in which rhM-CSF with the dose of 1×106 U/L made the viral titer drop dwon over 200 times. This antiviral activity of rhM-CSF could be partially neutralized by anti-IFN-βMcAb, but not by antiTNF-α, anti-IFN-α, or anti-IFA-γ McAb, indicating the mechanism of the antiviral activity of MCSF is related to the induction of IFN-β.