CD40 Ligand ; pharmacology ; HL-60 Cells ; drug effects ; Humans ; fas Receptor ; metabolism

OBJECTIVETo analyze the cloning result of CD40 mutant from RPMI8226 cells, a multiple myeloma (MM) cell line, and study the change of the expressions of costimulatory molecules and the apoptosis of RPMI8226 cells after activated with CD40.

METHODSCD40 gene mutant in RPMI8226 cell was detected by RT-PCR and DNA sequencing. The cell lines were cultured with sCD40L, L929/CD40L, soluble 5C11 (an anti-CD40 mAb) plate-bound 5C11 and their respective controls. Their growth curves, change of phenotypes and cell cycles were detected. The signalosome of CD40 on RPMI8226 cells were analyzed with laser scanning confocal microscope.

RESULTSThere was a single base substitution (TCA-->TTA) in the open reading frame of CD40 from RPMI8226 cells, resulting in the conversion of a amino acid (Ser124Leu). Only plate-bound antibody could inhibit RPMI8226 cell proliferation [(2.5 +/- 0.6) x 10(5) vs (7.8 +/- 1.2) x 10(5), P <0.05] and cause G1 arrested [(58.0 +/- 3.6)% vs (42.0 +/- 2.3)%, P <0.05]. muCD40 was translocated to CD40 signalosome while CD40 activated.

CONCLUSIONThe mutated CD40 in RPMI8226 cell might decrease its affinity to CD40L, leading to the disorder of CD40 signal.

Antibodies, Monoclonal ; pharmacology ; CD40 Antigens ; genetics ; immunology ; CD40 Ligand ; genetics ; pharmacology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; DNA Mutational Analysis ; Humans ; Multiple Myeloma ; genetics ; pathology ; Mutation ; Phenotype ; Transgenes

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

OBJECTIVETo investigate the effect of prolactin on CD40 and CD154 expressions on the surface of peripheral blood mononuclear cells in patients with systemic lupus erythematosus (SLE) and explore the role of prolactin in the pathogenesis of SLE.

METHODSThe serum prolectin level was detected in 30 SLE patients and 20 healthy volunteers, from whom peripheral blood mononuclear cells (PBMCs) were also isolated to examine the expressions of CD40 and CD154 using flow cytometry.

RESULTSCD154 significantly increased on the PBMCs in SLE patients with high serum prolectin level in comparison with that in patients with normal prolactin level or the normal controls (P<0.05). When the PBMCs were incubated with recombinant human prolactin, CD154 expression was significantly increased in SLE patients with normal serum prolactin level (P<0.05), but not in the normal control group (P>0.05). Incubation of the PBMCs in the presence of bromocriptine did not result in significantly decreased CD154 expression in SLE patients irrespective of the prolactin level, nor was significant difference found in CD40 expression on the surface of PBMCs between SLE patients and the normal controls(P>0.05).

CONCLUSIONProlactin plays an important role in the pathogenesis of SLE by increasing CD154 expression on the PBMCs, and bromocriptine produces no significant inhibitory effect on either endogenous or exogenous prolectin.

Adult ; CD40 Antigens ; metabolism ; CD40 Ligand ; metabolism ; Case-Control Studies ; Female ; Gene Expression Regulation ; drug effects ; Humans ; Leukocytes, Mononuclear ; drug effects ; metabolism ; Lupus Erythematosus, Systemic ; blood ; metabolism ; pathology ; Male ; Prolactin ; blood ; pharmacology

OBJECTIVETo determine the modulating effect of CD40 ligand (CD40L, CD154) on CD40-transfected human lung carcinomas and to assess the potential of CD40 as a therapeutic target.

METHODSTumor cells of a CD40-negative lung cancer cell lines (GLC-82) were transfected with a vector expressing CD40 cDNA. The transfected cell line, GLC-82/CD40, was shown to express high levels of CD40. GLC-82/CD40 cells after being exposed to 0.1 micro g/ml CD40L were examined for their surface expression, cell cycle, apoptosis and cell growth by flow cytometry and MTT assay.

RESULTSThe expression of MHC-I, ICAM-1 and Fas in GLC-82/CD40 cells was significantly increased, whereas that of EGFR was decreased. Cell proliferation was significantly inhibited by CD40L with an inhibition rate of 30% on day 5, but no change in cell cycle. All of the changes disappeared after 48 h incubation with CD40L. More significant changes were observed in Calu-3 cell lines which expressed high levels of CD40, but the CD40-negative GLC-82 cells were unresponsive to CD40L. None of the 3 cell lines showed significant changes in apoptosis upon CD40L treatment.

CONCLUSIONCD40, if over-expressed in tumor cells, could be considered as a potential therapeutic target.

Apoptosis ; drug effects ; Blotting, Western ; CD40 Antigens ; physiology ; CD40 Ligand ; pharmacology ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Cell Line, Tumor ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; Transfection

OBJECTIVETo explore the effect of CD40 blockade in suppressing acute rejection of renal graft in rats.

METHODSWith Wistar rats as the donor and male SD rats as the recipients, rat models of acute renal graft rejection was established. The rat models were divided into therapy group and control group, and in the former group, CD40 ligand (CD40L) monoclonal antibody was injected daily for 4 consecutive days starting on the next day following kidney transplantation. On day 5 after the transplantation, the renal graft was harvested for histological examination, and graft rejection was evaluated semiquantitatively.

RESULTSThe mean semiquantitative score of the renal graft was 0.63∓0.52 in the therapy group, significantly lower than that of the control group (3.72∓1.48, P<0.05).

CONCLUSIONCD40L monoclonal antibody can inhibit acute renal graft in rats.

Animals ; Antibodies, Monoclonal ; pharmacology ; therapeutic use ; CD40 Antigens ; antagonists & inhibitors ; immunology ; CD40 Ligand ; immunology ; Female ; Graft Rejection ; drug therapy ; prevention & control ; Graft Survival ; drug effects ; Kidney Transplantation ; adverse effects ; Male ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar

AIMTo investigate the significance of the calcineurin (CaN) activation in active lupus nephritis patient.

METHODSPeripheral blood mononuclear cells (PBMCs) were separated from twenty-one active LN patients and 12 healthy controls. Phosphatase activity of CaN was determined using the CaN assay kit by measuring the content of released PO4. Reverse transcription-PCR was used to detect the expression of CD40L mRNA. Flow cytometry analysis was used to detect the expression of CD40L in LN PBMC.

RESULTS(1) Increased activation of CaN in spontaneous cultured PBMC in active LN group was found as compared with control group (46.08 +/- 5.58 vs 8.81 +/- 3.61, P < 0.01). In stimulated by PMA/Ionomycin , activity of CaN in active LN group was also higher than that of control (69.34 +/- 12.59 vs 37.12 +/- 11.57, P < 0.01). (2) Relative content of CD40L in PBMC in active LN groups increased significantly as compared with the control groups under spontaneous and PMA/Ionomycin-induced culture, respectively (P < 0.01). (3) FK506 reduced significantly production of CD40L in spontaneous and PMA/Ionomycin-induced PBMC of LN.

CONCLUSIONElevated activation of CaN in active LN may participate in regulation overexpression of CD40L in PBMC of LN. Through inhibiting CaN activity, FK506 may prevent abnormal activation of CD40-CD40L costimulatory pathway in lupus nephritis.

Adolescent ; Adult ; CD40 Ligand ; metabolism ; Calcineurin ; metabolism ; Case-Control Studies ; Cells, Cultured ; Female ; Humans ; Leukocytes, Mononuclear ; metabolism ; Lupus Nephritis ; blood ; metabolism ; Male ; Middle Aged ; Tacrolimus ; pharmacology ; Young Adult

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 investigate the inhibition mechanisms of BAY11-7082 (IkappaB-alpha phosphorylation inhibitor) and Lactacystein (proteosome inhibitor) in CD154-induced NF-kappaB activation.

METHODSWe used recombinant CD154 to stimulate EBV/LMP1 negative Ramos B cell and observed the effects of BAY11-7082 and Lactacystein in CD154-induced NF-kappaB luciferase activation, phosphorylation and degradation of IkappaB-alpha, phosphorylation of p65, and nuclear translocation of NF-kappaB subunits upon CD154 stimulation.

RESULTSBoth BAY11-7082 and Lactacystein abrogated CD154-induced NF-kappaB luciferase activation in Ramos cells. While CD154-induced phosphorylation of p65, phosphorylation and degradation of IkappaB-alpha, and nuclear translocation of p50, p65, and c-Rel were all blocked by BAY11-7082; Lactacystein only inhibited degradation of IkappaB-alpha and p65 nuclear translocation.

CONCLUSIONBAY11-7082 and Lactacystein inhibit CD154-induced NF-kappaB activation through different mechanisms.

Acetylcysteine ; analogs & derivatives ; pharmacology ; Apoptosis ; drug effects ; Burkitt Lymphoma ; pathology ; CD40 Ligand ; pharmacology ; Cysteine Proteinase Inhibitors ; pharmacology ; Enzyme Activation ; drug effects ; Humans ; NF-kappa B ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Sulfones ; pharmacology ; Tumor Cells, Cultured

Cytokine and chemokine receptors play a key role in inflammation caused by rheumatoid arthritis (RA). Two isoforms of human CC chemokine receptor R2 (CCR2), the receptor of monocyte chemoattractant protein 1 (MCP-1), have been identified but their relative expression in fibroblast-like synoviocytes (FLS) and their contribution to inflammatory responses mediated by MCP-1 or inflammatory cytokines in patients with RA remain uncertain. We examined the pattern of expression of two CCR2 isoforms upon stimulation by proinflammatory cytokines and CD40 ligation. FLS were prepared from the synovial tissues of RA patients and cultured in the presence of MCP-1, soluble CD40 ligand (sCD40L), TGF-beta, IL-1beta, IL-18, IL-15, and LPS. CCR2A and CCR2B expression was examined by immunohistochemistry, RT-PCR and western blot analysis. IL-15, TNF-alpha and MCP-1 production was determined by ELISA. Immunohistochemistry showed that CCR2A is highly expressed in RA synovium compared with OA synovium. Transcripts of both CCR2A and CCR2B were detected in FLS. Exogenous MCP-1, CD40L, TGF-beta, and IL-15 significantly increased the expression of CCR2A but not CCR2B. Exposure of FLS to sCD40L caused strong upregulation of CCR2A but not of CCR2B protein expression. MCP-1 increased the proliferation of FLS and the production of IL-15, TNF-alpha, and IL-18. Because CCR2A is the main target of regulation by cytokines and CD40 ligation, the relatively higher expression of CCR2A on the cell surface suggests that this isoform of MCP-1 receptor functions as the principal mediator of inflammatory signals in RA FLS.
Arthritis, Rheumatoid/*metabolism ; CD40 Ligand/*pharmacology ; Cells, Cultured ; Chemokine CCL2/*pharmacology ; Chemokines/biosynthesis ; Fibroblasts/*metabolism ; Humans ; Protein Isoforms ; Receptors, CCR2/*biosynthesis ; Synovial Membrane/*pathology ; Transforming Growth Factor beta/*pharmacology