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

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

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

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

OBJECTIVE: To investigate the effect of miR-125b on T cell activation in patients with aplastic anemia (AA) and its molecular mechanism. METHODS: A total of 30 AA patients were enrolled in department of hematology, Binzhou Medical University Hospital from January 2018 to October 2021, as well as 15 healthy individuals as healthy control (HC) group. Peripheral blood mononuclear cells (PBMCs) were isolated, in which the levels of miR-125b and B7-H4 mRNA were detected by RT-qPCR. Immunomagnetic beads were used to separate naive T cells and non-naive T cells from AA patients and healthy people to detect the levels of miR-125b and B7-H4 mRNA. Lentivirus LV-NC inhibitor and LV-miR-125b inhibitor were transfected into cells, and T cell activation was detected by flow cytometry. The dual-luciferase reporter gene assay was used to detect the targetting relationship between miR-125b and B7-H4. RT-qPCR and Western blot were used to detect the levels of miR-125b, CD40L, ICOS, IL-10 mRNA and B7-H4 protein. RESULTS: Compared with HC group, the expression of miR-125b was up-regulated but B7-H4 mRNA was down-regulated in PBMCs of AA patients (P <0.05), and the proportions of CD4⁺CD69⁺ T cells and CD8⁺CD69⁺ T cells in PBMCs of AA patients were higher (P <0.05). The expression of miR-125b was significantly up-regulated but B7-H4 mRNA was down-regulated in both naive T cells and non-naive T cells of AA patients (P <0.05), and non-naive T cells was more significant than naive T cells (P <0.05). Compared with NC inhibitor group, the expression of miR-125b was significantly decreased, the expression level of CD69 on CD4⁺ and CD8⁺ T cells in PBMCs was also significantly decreased, while the luciferase activity was significantly increased after co-transfection of miR-125b inhibitor and B7-H4-3'UTR-WT in the miR-125b inhibitor group (P <0.05). Compared with NC inhibitor group, the mRNA and protein levels of B7-H4 were significantly increased in the miR-125b inhibitor group (P <0.05). Compared with miR-125b inhibitor+shRNA group, the expression levels of CD69 on CD4⁺ and CD8⁺ T cells were significantly increased, and the levels of CD40L, ICOS and IL-10 mRNA were also significantly increased in the miR-125b inhibitor+sh-B7-H4 group (P <0.05). CONCLUSION MiR-125b may promote T cell activation by targetting B7-H4 in AA patients.
Humans ; Anemia, Aplastic/genetics* ; CD40 Ligand/metabolism* ; Interleukin-10 ; Leukocytes, Mononuclear/metabolism* ; Luciferases ; MicroRNAs/genetics* ; RNA, Messenger/metabolism* ; Lymphocyte Activation ; T-Lymphocytes/metabolism*

OBJECTIVETo explore the effect of recombinant human soluble CD(40) ligand (rhsCD(40)L) and CD(40)L cDNA transfected cell (CD(40)L-TC) on the behavior of malignant B lymphocytes, and investigate the possibility of using rhsCD(40)L as a new bio-factor in tumor immunotherapy.

METHODrhsCD(40)L and CD(40)L-TC were obtained by gene recombinant techniques. Multiple myeloma cell lines, XG2, XG7, U266 and 8226, B-lymphoma cell lines, Raji and Daudi were selected to detect responses to rhsCD(40)L and CD(40)L-TC stimulation. Cell growth curve, cell cycle, early apoptosis as well as membrane surface molecules on these cell lines were analyzed.

RESULTS(1) The expression levels of CD(40) molecule on malignant B lymphocytes showed heterogeneity. High level of CD(40) on XG2, moderate on 8266, Raji, and Daudi, and no expression on U266 and XG7 were detected. The rhsCD(40)L stimulation gave rise to a typical homo-type cell aggregation of XG2 and Daudi. Meanwhile, at least 10 to 20 of CD(40)(+) XG2 or CD(40)(+) Daudi cells were found adherent to one pre-treat ed CD(40)L-TC. (2) Co-incubation with rhsCD(40)L (5 micro g/ml), or CD(40)L-TC (tumor cell: CD(40) = 5:1) resulted in a significant inhibition of in vitro cell growth of XG2, Raji and Daudi, with G(1)-phase arrest for XG2 and G(2)-phase for Raji and Daudi. These two kinds of CD(40) stimulators induced XG2, Raji and Daudi cells to apoptosis in vitro. The apoptotic rate for XG2 was 23.3% (rhsCD(40)L) and 18.8% (CD(40)L-TC), for Daudi 14.2% and 15.9%, and for Raji 11.6% and 8.9% respectively. (3) Phenotype analysis showed that CD(95) expression levels were significantly up-regulated on XG2, Raji and Daudi after stimulation with rhsCD(40)L or CD(40)L-TC, and CD(80) and CD(18) expression levels on Raji were respectively enhanced and decreased.

CONCLUSIONThe abilities to directly inhibit XG2, Daudi and Raji cell proliferation, to induce themapoptosis, as well as to up-regulate immune co-stimulator molecule CD(80) expression on Raji cells would make rhsCD(40)L a potential bio-factor for tumor immuno-therapy.

B-Lymphocytes ; drug effects ; metabolism ; pathology ; CD40 Antigens ; metabolism ; CD40 Ligand ; genetics ; metabolism ; pharmacology ; Cell Division ; drug effects ; Coculture Techniques ; DNA, Complementary ; genetics ; Humans ; Lymphoma, B-Cell ; metabolism ; pathology ; Recombinant Proteins ; pharmacology ; Time Factors ; Transfection ; Tumor Cells, Cultured ; drug effects

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

The study was aimed to investigate the expression of Toll-like receptor 4 (TLR4) on platelets and to determine whether platelet TLR4 involves in its activation induced by lipopolysaccharide (LPS). Human platelet-rich plasma (PRP) and platelet suspension obtained from 15 healthy individuals pretreated with a concentration of 0.2 microg/ml of LPS in the presence or absence of thrombin (1 U/ml) for 1 hour. The expressions of TLR4, CD62P (P-select) and CD40L on platelets were detected by flow cytometry, and platelet TLR4 expression was further determined by Western blot analysis. The results indicated that the percentage of TLR4-positive platelets induced by thrombin was increased by 32.34% compared with the resting platelets (25.44%, p < 0.05). TLR4 expression on platelets treated with LPS was remarkably elevated in the presence or absence of thrombin. However, the expression level of the former was much higher than that of the latter and thrombin stimulation alone (p < 0.05). Moreover, the similar results were found in Western blot analysis. Synchronously, expressions of CD62P and CD40L on resting platelets were 6.39% and 2.45%, they were also markedly increased when treated with thrombin (42.68% and 14.8%) and LPS respectively, and the increases of expression of CD62P and CD40L were more significant when stimulated with both LPS and thrombin (63.03% and 13.94%). Although anti-TLR4 antibody inhibited significantly the increase of TLR4, CD62P and CD40L on platelets induced by LPS, which did not affect their increase induced by thrombin. In conclusion, the evidence has been shown that functional TLR4 can be expressed on human platelets. It may involve in platelet activation as an important mediator of LPS-induced CD62P and CD40L expressions on platelets.
Adult ; Blood Platelets ; metabolism ; CD40 Ligand ; genetics ; Humans ; Lipopolysaccharides ; pharmacology ; Middle Aged ; P-Selectin ; metabolism ; Platelet Activation ; Toll-Like Receptor 4 ; metabolism

OBJECTIVETo examine whether the enhanced expression of CD40L cDNA on murine ovarian cancer (OVHM) cells could induce the secretion of Th1 cytokines from dendritic cells (DC).

METHODSOVHM cells were transfected with the full-length mouse CD40L cDNA by lipofectamine 2000 and then G418 resistant cells as positive cells were selected. They were examined for their expression of CD40L with flow cytometry. Bone marrow cells were firstly depleted of erythrocytes, macrophages, T and B cells with PE-conjugated magnetic beads, and then cultured in 10% FCS RPMI 1640 medium supplemented with recombinant mouse GM-CSF and IL-4 for 10 days. PKH67-labeled tumor cells were cultured with DC, and then the stained cells were analyzed for the expression of MHC-I, MHC-II, CD80, CD86, CCR7 in DC with flow cytometry. The expression of p40, p19, p35, p28, EBI3 subunits, IL-18, IFN-gamma, Mig gene in cocultured DC-tumor cells were detected by RT-PCR.

RESULTSThe CD40L cDNA was successfully transfected into OVHM cells. Bone marrow-derived DCs, when cultured with CD40L/OVHM, formed clusters with the tumors and showed an upregulated expression of MHC- I, MHC-II, CD80, CD86, CCR7. Expression of the IL-12, IL-23, IL-27, IL-18, interferon-gamma (IFN-gamma) and Mig (monokine induced by IFN-gamma) genes was induced in the DCs that were cultured with CD40L/OVHM but not with OVHM cells.

CONCLUSIONThese data directly showed that the expression of CD40L on ovarian cancer cells facilitates the interaction between DCs and tumors, enhances the maturation of DCs, induces secretion of Th1 cytokines, especially for IL-12, IL-23 and IL-27, which maybe one of the possible antitumor mechanism for CD40L-transfected ovarian cancer cell line.

Animals ; CD40 Ligand ; genetics ; metabolism ; Cell Line, Tumor ; Cells, Cultured ; Coculture Techniques ; Cytokines ; secretion ; DNA, Complementary ; genetics ; Dendritic Cells ; cytology ; metabolism ; Female ; Interleukin-12 ; secretion ; Interleukin-23 ; secretion ; Interleukins ; secretion ; Mice ; Ovarian Neoplasms ; metabolism ; pathology ; Th1 Cells ; secretion ; Transfection

OBJECTIVETo examine the in vivo anti-metastatic effect of enhanced expression of CD40L cDNA in murine ovarian cancer OVHM cells (CD40L-OVHM) injected into the spleen on liver metastasis in mice.

METHODSOVHM cells were inoculated into the spleen of 6 to 8 week-old female B6C3F1 (C57BL/6N x C3H/He) mice. The established liver metastasis was identified by histopathology (HE staining). OVHM cells, DNA-pMKITneo-OVHM cells or CD40L-OVHM cells were inoculated into the spleen of female B6C3F1 mice and the expressions of CD11c in splenic cells were detected by flow cytometry. The specific cytotoxicity of splenic cells was detected by MTT assay, and the serum cytokines of IFN-gamma, TNF-alpha, IL-12, IL-4 and IL-10 of the mice were measured by enzyme linked immunoabsorbent assay. The liver metastases and the survival time of the mice were also recorded.

RESULTSThe mouse models with liver metastasis by injecting tumor cells into the spleen of mice were established. The expression of CD11c and the specific killing rate in CD40L-OVHM cells group was significantly higher than that in the OVHM cells group and DNA-pMKITneo-OVHM cells group. The expressions of IFN-gamma, TNF-alpha and IL-12 in the CD40L-OVHM cells group were much more increased than OVHM cells group and DNA-pMKITneo-OVHM cells group, but the expressions of IL-4 and IL-10 in the CD40L-OVHM cells group were decreased significantly (p < 0.05). The average weights of livers and spleens of mice in CD40L-OVHM cells group were significantly lower than those of DNA-pMKITneo-OVHM cells group and OVHM cells group. The survival time of mice in CD40L-OVHM cells group was also significantly longer than that in the OVHM cells group and DNA-pMKITneo-OVHM cells group (P < 0.05).

CONCLUSIONThe data directly demonstrate that the expression of CD40L in ovarian cancer cells (CD40L-OVHM) can enhance the proliferation and differentiation of dendritic cells in the spleen and induce specific cytotoxic effect of T cells in the spleen, and may regulate the immune function of peripheral blood cells and the immune balance between Th1 cells and Th2 cells, which maybe the possible mechanism induced by CD40L in mice inhibiting the development of liver metastasis.

Animals ; CD11c Antigen ; metabolism ; CD40 Ligand ; genetics ; metabolism ; Cell Differentiation ; Cell Line, Tumor ; Cell Proliferation ; DNA, Complementary ; genetics ; Dendritic Cells ; cytology ; Female ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-4 ; metabolism ; Liver Neoplasms ; pathology ; secondary ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Ovarian Neoplasms ; metabolism ; pathology ; Spleen ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Necrosis Factor-alpha ; metabolism