OBJECTIVETo study the effect of PF4 on the adherence of leukemic CD34+ KG1a cell to human umbilical vein endothelial cell line ECV-304 cell and on the expression of adhesive molecules.

METHODSAdhesion assay and adhesion blocking assay were respectively applied to measure the effect of PF4 and/or adhesion molecule monoclonal antibodies on the adhesion property of KG1a. The expressions of adhesion molecules were determined by RT-PCR and FACS analysis.

RESULTSThe adhesion of KG1a cells to ECV-304 was significantly enhanced in the presence of PF4. Such enhancement was also observed when KG1a or ECV-304 cells were separately treated with PF4 before interaction. The adhesion capacity of KG1a cells was reduced when cells were co-incubated with the blocking monoclonal antibodies (MoAbs) against CD49d, CD106, CD54, respectively. In contrast, MoAbs against CD62L, CD62P and CD62E had no such effect. During a period of 3 hours when KG1a or ECV-304 cells were respectively incubated with PF4, the mRNA expressions of CD49 d, CD54 were up-regulated. Furthermore, when KG1a or ECV-304 cells were incubated with PF4 for 2 hours, respectively, the percentages of CD49d+ KG1a cells and CD54+ ECV-304 were increased significantly.

CONCLUSIONPF4 can enhance KG1a cell adhesive capacity by increasing the expressions of adhesion molecules.

Antigens, CD34 ; metabolism ; Cell Adhesion ; drug effects ; Cell Adhesion Molecules ; metabolism ; Cell Line, Tumor ; Humans ; Leukemia, Myeloid, Acute ; immunology ; pathology ; Platelet Factor 4 ; pharmacology ; Umbilical Veins ; cytology

The human colorectal carcinoma-associated GA733 antigen epithelial cell adhesion molecule (EpCAM) was initially described as a cell surface protein selectively expressed in some myeloid cancers. Gangliosides are sialic acid-containing glycosphingolipids involved in inflammation and oncogenesis. We have demonstrated that treatment with anti-EpCAM mAb and RAW264.7 cells significant inhibited the cell growth in SW620 cancer cells, but neither anti-EpCAM mAb nor RAW264.7 cells alone induced cytotoxicity. The relationship between ganglioside expression and the anti-cancer effects of anti-EpCAM mAb and RAW264.7 was investigated by high-performance thin-layer chromatography. The results demonstrated that expression of GM1 and GD1a significantly increased in the ability of anti-EpCAM to inhibit cell growth in SW620 cells. Anti-EpCAM mAb treatment increased the expression of anti-apoptotic proteins such as Bcl-2, but the expression of pro-apoptotic proteins Bax, TNF-alpha, caspase-3, cleaved caspase-3, and cleaved caspase-8 were unaltered. We observed that anti-EpCAM mAb significantly inhibited the growth of colon tumors, as determined by a decrease in tumor volume and weight. The expression of anti-apoptotic protein was inhibited by treatment with anti-EpCAM mAb, whereas the expression of pro-apoptotic proteins was increased. These results suggest that GD1a and GM1 were closely related to anticancer effects of anti-EpCAM mAb. In light of these results, further clinical investigation should be conducted on anti-EpCAM mAb to determine its possible chemopreventive and/or therapeutic efficacy against human colon cancer.
Animals ; Antibodies, Monoclonal/*immunology/*therapeutic use ; Antigens, Neoplasm/*immunology ; Apoptosis/drug effects ; Cell Adhesion Molecules/*immunology ; Cell Line ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Colon/drug effects/immunology/metabolism/pathology ; Colonic Neoplasms/*drug therapy/genetics/*immunology/pathology ; Gangliosides/genetics/*immunology ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; Male ; Mice ; Mice, Inbred BALB C

Intrahepatic cholangiocarcinoma (ICC), a malignant tumor derived from the intrahepatic bile duct epithelium, has a poor prognosis and is refractory to conventional chemotherapy and radiation therapy. Thus, there is an urgent need to develop new effective therapeutic strategies for this disease. We previously found that L1 cell adhesion molecule (L1CAM) plays an important role in tumor progression of ICC, and we generated a murine mAb, A10-A3 (IgG1), that binds to the Ig1 domain of L1CAM. In the present study, we further characterized A10-A3, constructed a chimeric A10-A3 antibody (cA10-A3) containing the constant regions of human IgG1, and evaluated the therapeutic potential in a human ICC xenograft nude mice model. The affinities (K D) of A10-A3 and cA10-A3 for soluble L1CAM were 1.8 nM and 1.9 nM, respectively, as determined by competition ELISA. A10-A3 inhibited L1CAM homophilic binding and was slowly internalized into the tumor cells, but it did not significantly inhibit proliferation of ICC cells in vitro. cA10-A3 mediated antibody-dependent cell-mediated cytotoxicity in vitro and displayed anti-tumor activity in the ICC animal model. These results suggest that the humanized A10-A3 antibody may have potential as an anticancer agent for the treatment of ICC.
Animals ; Antibodies, Monoclonal/genetics/*immunology ; Antibody-Dependent Cell Cytotoxicity ; Bile Ducts, Intrahepatic/drug effects/immunology/pathology ; CHO Cells ; Cell Adhesion/drug effects ; Cell Proliferation/drug effects ; Cholangiocarcinoma/*drug therapy/immunology/pathology ; Cricetinae ; Disease Models, Animal ; Endocytosis/drug effects ; Humans ; Immunoglobulin G/genetics/*immunology ; Liver Neoplasms/*drug therapy/immunology/pathology ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Neural Cell Adhesion Molecule L1/genetics/*immunology/metabolism ; Protein Binding ; Protein Structure, Tertiary ; Recombinant Fusion Proteins/immunology/metabolism/*therapeutic use

To investigate the effects of stromal cell-derived factor 1 (SDF-1) and platelet factor 4 (PF4) on the homing-related function of expanded ex vivo umbilical cord blood CD34(+) cells, purified cord blood CD34(+) cells were cultured in serum-free medium containing a HGF combination of FL + SCF + TPO (FST) with either 100 ng/ml SDF-1 alone, 100 ng/ml PF4 alone, or both of these 2 cytokines. The expansion rate of CD34(+) cells, colony formation, homing-related functions including expression of homing-related adhesion molecules of expanded CD34(+) cell, adhesion activity and chemotactic function of the re-selected expanded CD34(+) cells were evaluated at different time points. The results showed that expansion rate of CD34(+) cells and expansion multiple of CFU in SDF-1 groups were higher than those in control. The expression of CD49e on the expanded CD34(+) cells was remarkable up-regulated, in contrast, expression of CXCR-4 on the expanded CD34(+) cells was remarkable down-regulated in SDF-1 groups. The expression of CD49e, CD54 and CXCR-4 on the expanded CD34(+) cells were remarkably up-regulated in the PF4 groups. In all the SDF-1 group, PF4 group and SDF-1 plus PF4 group, the ability of expanded CD34(+) cells adhering to fibronectin layer were higher than those in the control on day 10. Spontaneous migration rate of expanded CD34(+) cells in SDF-1 groups were higher than those in control, while SDF-1-induced migration rate were lower than those in control on day 10. SDF-1-induced migration rate in PF4 groups were higher than those in control on day 10. Spontaneous and SDF-1-induced migration rate of expanded CD34(+) cells in the SDF-1 plus PF4 groups were higher than those in control on day 10. It is concluded that, SDF-1 and PF4 can up-regulate expression of adhesion molecules on expanded CD34(+) cells, and retain the adherent and migration ability of expanded CD34(+) cells, which is helpful for the homing of expanded CD34(+) cells. In short, SDF-1 and PF4 are helpful for the homing-related function of the expanded UCB HSPC.
Antigens, CD34 ; blood ; immunology ; Cell Adhesion ; drug effects ; Cells, Cultured ; Chemokine CXCL12 ; Chemokines, CXC ; pharmacology ; Chemotaxis ; immunology ; physiology ; Culture Media, Serum-Free ; Fetal Blood ; cytology ; immunology ; Hematopoietic Stem Cells ; cytology ; drug effects ; Humans ; Platelet Factor 4 ; pharmacology

OBJECTIVETo study the immunocharacteristics of bone marrow mesenchymal stem cell (MSC) and provide experimental evidence for the potential therapeutic application.

METHODSMSCs were isolated from rat bone marrow and confirmed by immunophenotype, and the growth dynamic and cell cycle were analyzed. MSCs were cultured with or without 200 U/ml interferon gamma (IFNg) , the expression of PDL-1, CD54, CD40, CD80, CD86, MHC-I, and MHC-II was detected by flow cytometry. MSCs were used as regulatory cells in mixed lymphocyte reaction (MLR), the PDL-1 and CD54 molecules on MSCs were blocked to explore their roles in MLR. The IFN, IL-2, IL-4 and IL-10 molecules in culture supernatant were quantified by ELISA. The homing of MSCs to liver and induction of microchimerism were analyzed after MSCs transplantation.

RESULTSThe purity of MSCs was high. The growth curve showed that the first two days were the lag phase; the third, fourth, fifth days were the log phase; the sixth and seventh days were the stationary phase. Flow cytometry indicated that 76.0%+/-2.0% of the MSCs were in G1/G0 phase, 13.0%+/-2.0% in S phase, 10.0%+/-1.7% in G2 and M phase. IFNg treatment led to up-regulation of CD54, PDL-1, MHC-I and MHC-II, however, CD40, CD80 and CD86 were not expressed on MSCs even after IFNg treatment. MSCs inhibited MLR, IFNg treatment enhanced the inhibitory effect of MSCs on MLR. Blocking of PDL-1 or CD54 on MSCs partially alleviated the inhibition effect. There were high levels of IFNg and IL-10, and low level of IL-4 in the culture supernatant of MLR, however, IL-2 was not detected. MSCs can home to the liver and induce formation of microchimerism after transplantation.

CONCLUSIONIFNg treatment enhances the inhibitory effect of MSCs on MLR, PDL-1 and CD54 are key molecules mediating this inhibitory effect. MSC can home to the liver and induce formation of microchimerism after transplantation.

Animals ; B7-1 Antigen ; immunology ; metabolism ; Bone Marrow Cells ; drug effects ; immunology ; metabolism ; Cell Proliferation ; Cells, Cultured ; Intercellular Adhesion Molecule-1 ; immunology ; metabolism ; Interferon-gamma ; administration & dosage ; pharmacology ; Lymphocyte Activation ; Lymphocyte Culture Test, Mixed ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; drug effects ; immunology ; metabolism ; Rats ; T-Lymphocytes ; drug effects ; immunology ; metabolism

We investigated the effects of mixed leukocyte reaction (MLR), hydrocortisone (HC) and cyclosporine A (CsA) on the expression of leukocyte adhesion molecules on the mesangial (MC) and endothelial cells (EnC). Cell surface enzyme immunoassay showed that INFnu, IL-1beta, or TNF alpha stimulated expression of ICAM-1, or VCAM-1 on MC after 24 hours. Flow cytometric analysis demonstrated that MLR supernatant induced a marked increase in mean fluorescence of or % of cells highly expressing intercellular adhesion molecule(ICAM)-1 or vascular cell adhesion molecule (VCAM)-1 on both cells after 24 hours (p<0.001). HC treatment(300 ng/ml) during MLR effectively inhibited MLR-induced upregulation of ICAM-1 and VCAM-1 on both cells (p<0.005). When MLR supernatant with HC was added to adhesion molecule assay, there was no inhibitory effect of HC on VCAM-1. CsA treatment (500 ng/ml) during MLR caused a modest decrease in upregulation of VCAM-1 on EnC (p<0.05), but had no effects on ICAM-1 on both cells. CsA directly decreased expression of VCAM-1 on MC. In conclusion, alloreactive lymphocytes and monocytes upregulate the expression of VCAM-1 and ICAM-1 on target cells probably by the mediation of cytokines. HC effectively prevents MLR-induced upregulation of VCAM-1 and ICAM-1. CsA does not increase the expression of VCAM-1 and ICAM-1.
Cells, Cultured ; Cyclosporine/*pharmacology ; Endothelium, Vascular/drug effects/*immunology ; Glomerular Mesangium/drug effects/*immunology ; Human ; Hydrocortisone/*pharmacology ; Intercellular Adhesion Molecule-1/*biosynthesis ; Interleukin-1/pharmacology ; Leukocytes/drug effects/*metabolism ; Lymphocyte Culture Test, Mixed ; Monocytes/drug effects/metabolism ; Tumor Necrosis Factor/pharmacology ; Vascular Cell Adhesion Molecule-1/*biosynthesis

We investigated the effects of mixed leukocyte reaction (MLR), hydrocortisone (HC) and cyclosporine A (CsA) on the expression of leukocyte adhesion molecules on the mesangial (MC) and endothelial cells (EnC). Cell surface enzyme immunoassay showed that INFnu, IL-1beta, or TNF alpha stimulated expression of ICAM-1, or VCAM-1 on MC after 24 hours. Flow cytometric analysis demonstrated that MLR supernatant induced a marked increase in mean fluorescence of or % of cells highly expressing intercellular adhesion molecule(ICAM)-1 or vascular cell adhesion molecule (VCAM)-1 on both cells after 24 hours (p<0.001). HC treatment(300 ng/ml) during MLR effectively inhibited MLR-induced upregulation of ICAM-1 and VCAM-1 on both cells (p<0.005). When MLR supernatant with HC was added to adhesion molecule assay, there was no inhibitory effect of HC on VCAM-1. CsA treatment (500 ng/ml) during MLR caused a modest decrease in upregulation of VCAM-1 on EnC (p<0.05), but had no effects on ICAM-1 on both cells. CsA directly decreased expression of VCAM-1 on MC. In conclusion, alloreactive lymphocytes and monocytes upregulate the expression of VCAM-1 and ICAM-1 on target cells probably by the mediation of cytokines. HC effectively prevents MLR-induced upregulation of VCAM-1 and ICAM-1. CsA does not increase the expression of VCAM-1 and ICAM-1.
Cells, Cultured ; Cyclosporine/*pharmacology ; Endothelium, Vascular/drug effects/*immunology ; Glomerular Mesangium/drug effects/*immunology ; Human ; Hydrocortisone/*pharmacology ; Intercellular Adhesion Molecule-1/*biosynthesis ; Interleukin-1/pharmacology ; Leukocytes/drug effects/*metabolism ; Lymphocyte Culture Test, Mixed ; Monocytes/drug effects/metabolism ; Tumor Necrosis Factor/pharmacology ; Vascular Cell Adhesion Molecule-1/*biosynthesis

OBJECTIVETo explore the impact of mobilization with recombinant human granulocyte colony stimulated factor (rhG-CSF) on the migration and adhesive function and their related signal mechanism mediated by the CXCR4 and lymphocyte function antigen-1 (LFA-1) molecules on the surfaces of CD4(+) T cells.

METHODSBefore and at day 5 on rhG-CSF mobilization, the expression rates of CXCR4 and LFA-1 (CD11a) on CD4(+) T cells in the peripheral blood were detected by tricolor fluorescence labeling, and the migration and adhesive activities of CD4(+) T cells to stroma cell-derived factor 1 alpha (SDF-1 alpha) and intercellular adhesion molecule-1 (ICAM-1) were also tested.

RESULTSThe expression of CXCR4 on CD4(+) T lymphocytes was (84.58 +/- 20.31)% before mobilization and (81.23 +/- 22.46)% at day 5 on mobilization. The expression of LFA-1 on CD4(+) T lymphocytes before and at day 5 on mobilization was 100%. There was no significant difference in the expression CXCR-4 and LFA-1 on CD4(+) T lymphocytes whether mobilization (P > 0.05). SDF-1 alpha induced 4 hours' CD4(+) T cells migration didn't change markedly before and after mobilization \[(28.5 +/- 10.3)% vs (31.2 +/- 8.9)%\] (P > 0.05). The adhesive activity of CD4(+) T cells to ICAM-1 was decreased from (85.59 +/- 14.21)% to (61.45 +/- 15.07)% after mobilization (P < 0.05).

CONCLUSIONSThe expression of CXCR4 and LFA-1 on CD4(+) T lymphocytes didn't change markedly during rhG-CSF mobilization, but the adhesive activity of CD4(+) T cells to ICAM-1 was frustrated after that.

CD4-Positive T-Lymphocytes ; drug effects ; immunology ; metabolism ; physiology ; Cell Adhesion ; Cell Movement ; Cells, Cultured ; Chemokine CXCL12 ; physiology ; Granulocyte Colony-Stimulating Factor ; pharmacology ; Humans ; Intercellular Adhesion Molecule-1 ; physiology ; Lymphocyte Function-Associated Antigen-1 ; metabolism ; Receptors, CXCR4 ; metabolism ; Recombinant Proteins

OBJECTIVETo study the role of integrin alpha 6 in cell attachment, spread, survival/proliferation and differentiation of human hepatocellular carcinoma (HCC) BEL-7402 cells on various substrates by monoclonal antibody against the extracellular domain of alpha 6 subunit (IA6ED McAb).

METHODSThe effect of McAb on attachment and spread of BEL-7402 cells on LN or FN substrate was examined. MTT analysis was used to examine the cell survival/proliferation, gelatin zymography to the matrix metalloproteinases (MMPs) secreted by BEL-7402 cells, and microparticle immunoabsorbent kit to AFP secretion while the cells were cultured on LN-, FN- or Matrigel-coated substrates.

RESULTSThe cell attachment, spread and survival/proliferation were inhibited. Moreover importantly, the malignant cell dedifferentiation and abnormal differentiation on LN-coated substrate were also strongly inhibited by IA6ED McAb.

CONCLUSIONLN and integrin alpha 6 regulate human HCC cell phenotypes of survival/proliferation and differentiation. The phenotypes of dedifferentiation and abnormal differentiation can be reversed by blocking the interaction between integrin alpha 6 and LN using IA6ED McAb, which may lower metastatic potency of tumor cells.

Antibodies, Monoclonal ; pharmacology ; Carcinoma, Hepatocellular ; pathology ; Cell Adhesion ; drug effects ; Humans ; Integrin alpha6 ; immunology ; physiology ; Laminin ; physiology ; Liver Neoplasms ; pathology ; Phenotype ; Receptors, Laminin ; physiology ; Tumor Cells, Cultured

BACKGROUNDThe presence of autoantibodies against multiple epidermal proteins is an important feature in paraneoplastic pemphigus (PNP). Circulating anti-desmoglein 3 autoantibody, the major pathogenic autoantibody in pemphigus vulgaris (PV), has been proved pathogenic in PNP. Because of many clinical differences between PNP and PV, we speculate about the involvement of other autoantibodies in the pathogenesis of PNP. Envoplakin (EPL) and periplakin (PPL) are recognized by most PNP sera. Their linker subdomains are highly homologous and necessary for the association of intermediate filaments.

METHODSWe characterized the autoantibodies against the linker subdomains of EPL and PPL in PNP patients' sera and their associated tumors by enzyme-linked immunosorbent assay (ELISA) and immunofluorence. We also applied the purified autoantibodies against EPL and PPL from PNP sera to cultured human epidermal keratinocytes (HEK), to evaluate the changes of cell-cell adhesion.

RESULTSAutoantibodies against EPL and PPL were detected in most PNP patients by ELISA, and the decrease of these autoantibodies after removal of the tumors was roughly comparable to the improvement of clinical symptoms. Cultured tumor cells from PNP patients secreted these autoantibodies. Specific immunoglobulin receptors for EPL and PPL were found on B lymphocytes in tumors from PNP. Furthermore, purified anti-EPL and anti-PPL autoantibodies from PNP sera were capable of dissociating cultured human epidermal keratinocytes.

CONCLUSIONAutoantibodies against EPL and PPL may also be pathogenic in PNP.

Adolescent ; Adult ; Autoantibodies ; immunology ; pharmacology ; Cell Adhesion ; drug effects ; Cells, Cultured ; Desmoglein 3 ; immunology ; Enzyme-Linked Immunosorbent Assay ; Epidermis ; cytology ; Female ; Humans ; Keratinocytes ; cytology ; drug effects ; Male ; Membrane Proteins ; immunology ; Middle Aged ; Paraneoplastic Syndromes ; immunology ; metabolism ; Pemphigus ; immunology ; metabolism ; Plakins ; immunology ; Protein Precursors ; immunology ; Young Adult