To obtain chicken CD40L protein, the cDNA was prepared from chicken splenic cells and used as a template to clone and amplify CD40L by PCR. The target gene was cloned into pFastBac vector to construct a pFastBac-chCD40L donor plasmid. Recombinant plasmid was transformed into DH10Bac and recombinant Bacmid-chCD40L was obtained. The Bacmid-chCD40L plasmid was transfected into sf9 insect cells to obtain His-chCD40L protein. In addition, the target gene was cloned into pQM01 vector to construct a pQM01-chCD40L plasmid, recombinant plasmid was transfected into HEK 293T cells to obtain Strep-chCD40L protein. The chCD40L protein was purified by affinity chromatography, and the concentration of purified chCD40L protein was determined to be 0.01 mg/mL. Primary cells were isolated from the bursal tissue of 3-week old SPF chickens, and the chCD40L protein was added to the culture medium to stimulate cells. The chCD40L could bind to CD40 on B cells as examined by Western blotting, indirect immunofluorescence assay and flow cytometry, suggesting that chCD40L protein is biologically active. We successfully obtained chicken CD40L protein of biological activity, which laid the foundation in the in vitro culture of primary B lymphocytes for the isolation and diagnosis of virulent IBDV.
Animals ; Baculoviridae/genetics* ; CD40 Ligand/genetics* ; Chickens ; Cloning, Molecular ; Genetic Vectors/genetics* ; Recombinant Proteins/genetics*

The interaction of CD40 with its cognate ligand, CD40L (CD154), plays important roles in immune responses. Blockade of CD40-CD40L signal pathway can protect the progression of antibody- and cell-mediated autoimmune diseases, and reduce allograft rejection thus prolonging graft survival, even engendering long-lived antigen-specific tolerance. The present study aims to enhance the binding activity of CD40 by incorporating an isoleucine zipper (IZ) trimeric motif into CD40 ectodomain to promote the formation of soluble CD40 trimers, which would be useful for blocking CD40-CD40L interaction. A prokaryotic expression vector for soluble human CD40 ectodomain fused with an IZ motif and a hexa-histidine (His6) tag at its carboxyl terminus (sCD40IZ) was constructed by multiple round PCR using cloned CD40 cDNA as a template. The recombinant sCD40IZ protein was expressed highly in Escherichia coli (E. coli) with a molecular weight of 27kD, which is consistent with its theoretical value. It mainly existed in inclusion bodies. After refolding from inclusion bodies, soluble sCD40IZ protein was purified by gel filtration. Its molecular weight in solution was about 91kD when determined by gel filtration, suggesting that it most probably existed in the form of trimers. Moreover, this protein could bind to CD40L expressed on Jurkat T cells and its binding activity was significantly higher than that of soluble CD40 without an IZ motif. These results suggest that incorporation of an IZ motif at the carboxyl terminus of soluble CD40 can facilitate the formation of trimers and enhance its binding activity with CD40L. Thus, the trimeric CD40 protein may be used to block CD40-CD40L signal pathway, suggesting that it may have potential application in preventing autoimmune diseases and transplantation rejection.
CD40 Antigens ; biosynthesis ; genetics ; metabolism ; CD40 Ligand ; metabolism ; Escherichia coli ; genetics ; metabolism ; Humans ; Isoleucine ; biosynthesis ; genetics ; Leucine Zippers ; genetics ; Protein Multimerization ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; metabolism

CD40/CD40L is a pair of complementary transmembrane glycoproteins, expressed on immune cells, endothelial cells, smooth muscle cells, platelets and other cells involved in regulation of immunity, inflammation, coagulation and other pathophysiologic states. A large number of researches have demonstrated that, when atherosclerosis occurs, CD40L ligates CD40; subsequently CD40 is activated and stimulates downstream signaling pathways, including nuclear factor-kappaB, with consequent up-regulation of proinflammatory and proatherogenic genes. Thus it plays an important role in the occurrence, development and plaque-rupture of atherosclerosis. CD40/CD40L is a bridge between immunity, inflammation, and a hypercoagulable state, and may be an important target for prevention and treatment of cardiovascular disease.
Animals ; Atherosclerosis ; genetics ; physiopathology ; CD40 Antigens ; genetics ; CD40 Ligand ; genetics ; Humans ; Immunity ; physiology ; Inflammation ; physiopathology ; NF-kappa B ; metabolism ; Polymorphism, Genetic ; Thrombophilia ; physiopathology

OBJECTIVETo investigate the expression levels of CD40, sCD40L, hs-CRP, WBC in acute coronary syndrome (ACS) patients and the association between CD40-1C/T single nucleotide polymorphism and risk of ACS in Han Chinese, moreover, the regulatory effects of IFN-gamma and fluvastatin on the expression of CD40 in peripheral blood mononuclear cell (PBMNC) were also observed.

METHODS(1) 160 ACS patients and 92 control patients diagnosed by coronary angiography were recruited. Enzyme linked immunosorbent assay, particle enhanced immunoturbidimetric assay, flow cytometry were used to detect the levels of soluble CD40L, hs-CRP, and WBC count. (2) The CD40 genotype and allele frequency were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing technology. (3) PBMNC were separated by density gradient centrifugation heparinized venous blood from 40 ACS patients, cultured for 24 h with or without 100 ng/ml IFN-gamma in the absence or present of 10 micromol/L fluvastatin. The CD40 expression levels were then detected by flow cytometry.

RESULTSInflammatory cytokine CD40, sCD40L, hs-CRP levels were significantly higher in ACS patients than in controls. The CD40-1C allele frequency was 0.606 in ACS group and 0.489 in controls, while T allele frequency was 0.394 in ACS group and 0.511 in controls. The frequency of CC genotype was significantly higher in ACS group than in controls (P < 0.01). C allele carriers had significantly higher risk of ACS (OR = 1.608, 95%CI: 1.12 - 2.32, P = 0.011). CD40 production increased after 24 h culturing and the CD40 levels were significantly higher in subjects with CC genotype than that in subjects with CT or TT genotype [CC: (14.78 +/- 4.56) MFI, CT: (11.98 +/- 4.12) MFI, TT: (9.86 +/- 3.83) MFI, P < 0.05]. IFN-gamma further increased PBMNC CD40 expressions in all subjects after culturing for 24 h and fluvastatin equally inhibited IFN-gamma induced PBMNC CD40 expression from various genotypes (CC, CT, TT was 30.3%, 26.3%, 29.3% respectively, all P > 0.05).

CONCLUSIONInflammatory cytokines were increased in ACS patients and CD40-1C/T polymorphism is associated with higher risk for ACS in Han Chinese.

Acute Coronary Syndrome ; genetics ; Aged ; CD40 Antigens ; genetics ; metabolism ; CD40 Ligand ; genetics ; metabolism ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide

Antiphospholipid Syndrome ; complications ; Atherosclerosis ; etiology ; B-Lymphocytes ; immunology ; CD11a Antigen ; genetics ; CD27 Ligand ; genetics ; CD40 Ligand ; genetics ; DNA Methylation ; Epigenesis, Genetic ; Humans ; Lupus Erythematosus, Systemic ; etiology ; genetics ; immunology

As CD40 transduces activation signals involved in inflammatory and immune disorders, we explored the expression and response to CD40 engagement in human glioma cell lines in this study. The CD40 expression in BT-325 and U251 cells was flow cytometrically detected. The cells were incubated with srhCD40L for 72 h to assess its effects on cell growth in vitro. TNF-α expression was quantified by real-time PCR, and protein expression was analyzed by ELISA. The I-κb mRNA was detected by RT-PCR. I-κB expression decreased after stimulation with 1 μg/mL srhCD40L, but it was upregulated after the cells were pretreated with CD40 antibody. srhCD40L significantly inhibited the proliferation of the CD40+ human glioma cells. The stimulation of CD40+ glioma cells with soluble CD40L (CD154) up-regulated the expression of TNF-α at both mRNA and protein levels. We are led to conclude that CD40L/CD40 could inhibit human glioma cells through I-κb signaling pathway. Interferon-γ can augment CD40 expression and the inhibitory effect of CD40 ligand on cell growth in vitro. These results suggest that srhCD40L may benefit the therapy strategy of glioma.
CD40 Antigens ; metabolism ; CD40 Ligand ; metabolism ; Cell Proliferation ; Cells, Cultured ; Glioma ; genetics ; metabolism ; pathology ; Humans ; NF-kappa B ; metabolism ; Signal Transduction ; physiology ; Tumor Cells, Cultured

OBJECTIVESTry to induce liver-derived dendritic cells proliferation by plasmid-IL-3 and CD40L genes in mice in vivo.

METHODSRapid tail-vein injection of large amounts of plasmid-carrying genes was performed to transfect genes in mice livers. Liver nonparenchymal cells were isolated by Percoll gradient centrifugation. Dendritic cell markers were detected and dendritic cells were sorted out by flow cytometry. Morphology of dendritic cells was studied microscopically (with Giemsa staining) and under scanning electron microscopy.

RESULTSLiver nonparenchymal cells dramatically increased in the liver lobules, portal and periportal areas in the treated group, but not in the control group. B220+/DEC205+ dendritic cells were detected and sorted by flow cytometry. There were more B220+/DEC205+ dendritic cells (16.0%) in the experiment group than those in the control group (1.1%). Morphologically, the sorted B220+/DEC205+ cells showed irregular shaped nuclei, paucity of cytoplasmic granules and extensive cytoplasmic processes.

CONCLUSIONB220+/DEC205+ dendritic cells were expanded in vivo in mice livers by rapid tail-vein injection of plasmid-carrying genes encoding IL-3 and CD40L in a large amount. Inducing liver dendritic cell proliferation in vivo provides a more convenient way for studying the biology of these cells.

Animals ; CD40 Ligand ; genetics ; Dendritic Cells ; cytology ; Flow Cytometry ; Hepatocytes ; cytology ; Interleukin-3 ; genetics ; Male ; Mice ; Mice, Inbred C57BL ; Transfection

Animals ; CD40 Ligand ; genetics ; metabolism ; Carcinoma, Hepatocellular ; genetics ; metabolism ; therapy ; Genetic Therapy ; Liver Neoplasms ; genetics ; metabolism ; therapy ; Mice ; Neoplasms, Multiple Primary ; genetics ; metabolism ; therapy ; Transgenes ; genetics

To obtain the expression of Isoleucine Zipper modified soluble CD40L (IZ-sCD40L) in Pichia pastoris, firstly, DNA fragment of IZ-sCD40L was obtained by PCR and over-lap PCR . Then the expression vector pPICZaA-IZ-sCD40L was constructed. Nucleotide sequencing analysis indicated that the DNA fragment of IZ-sCD40L was correctly inserted into the pPICZaA vector. Linearized pPICZ(alpha)A-IZ-sCD40L was introduced into Pichia pastoris GS115. Positive clone was selected by PCR and its phenotype was determined. The positive clone was introduced with methanol. The results of SDS-PAGE and Western blot showed that product was recombinant Isoleucine Zipper modified soluble CD40L fusion protein.
Angiotensin II ; CD40 Ligand ; biosynthesis ; genetics ; Cloning, Molecular ; Isoleucine ; analogs & derivatives ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Plasmids ; Polymerase Chain Reaction ; methods ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Recombination, Genetic

OBJECTIVE: To detect variant of the CD40L gene and infection of Jamestown Canyon virus (JCV) in a 7-year-and-9-month-old boy with co-commitment progressive multifocal leukoencephalopathy (PML) and X-linked hyper IgM syndrome (XHIGM). METHODS: Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA. The 5 exons and exon/intronic boundaries of the CD40L gene were subjected to PCR amplification and sequencing. Suspected variants were analyzed by using bioinformatic software. The JCV gene was amplified from genomic DNA by nested PCR and sequenced. RESULTS: The child was found to harbor a hemizygous c.506 A>C (p.Y169S) missense variant in exon 5 of the CD40L gene. The variant may affect the TNFH domain of the CD40L protein and result in structural instability and loss of hydrophobic interaction between CD40L and CD40. As predicted by PolyPhen2 and SIFT software, the variant was probably damaging (score = 1.00) and deleterious (score= -8.868). His mother was found to be a heterozygous carrier, while the same variant was not found in his father. Gel electrophoresis of the nested PCR product revealed presence of target JCV band, which was confirmed to be 99% identical with the JCV gene by sequencing. CONCLUSION The patient was diagnosed with co-commitment XHIGM and PML based on the testing of the CD40L gene and JCV infection.
Adult ; CD40 Ligand/genetics* ; Child ; Exons/genetics* ; Female ; Humans ; Hyper-IgM Immunodeficiency Syndrome, Type 1/genetics* ; Leukoencephalopathy, Progressive Multifocal/genetics* ; Male ; Mutation, Missense ; Polymerase Chain Reaction