Prostaglandin E2(PGE2) has been implicated as an immunosuppressive agent and plasma levels of PGE2 are elevated in patients sustaining thermal injury. We examined the effect of 10(-7) M prostaglandin E2(PGE2) on human polymorphonuclear leukocytes (PMN) to determine whether it directly inhibits stimulated responses of these cells. At this concentration, PGE2 alone was incapable of stimulating PMN intracellular hydrogen peroxide production (indirectly assayed by fluorescence of 2',7'ichlorofluorescin) or expression of the PMN CD11b/CD16 surface glycoproteins. PMN incubated in the presence of the soluble stimul phorbol myristate acetate(PMA, 100 ng/ml) or recombinant human C5a(rHC5a, 10(-8) M) generated significant amounts of hydrogen peroxide, increased their CD11b expression and decreased their CD16 expression. Pre-incubation of cells with PGE2 caused significant inhibition of all the observed changes stimulated by rHC5a. In contrast, events stimulated by PMA were not affected by preincubation of cells with PGE2. We conclude that PGE2, in concentrations identical to those found in the plasma of patients with burn injuries, is capable of selectively inhibiting some stimulated events and phenotypic expression of PMN in vitro study.
Dinoprostone/*pharmacology ; Dose-Response Relationship, Drug ; Human ; Hydrogen Peroxide/metabolism ; Immunosuppressive Agents/*pharmacology ; Macrophage-1 Antigen/biosynthesis ; Neutrophils/*drug effects/immunology ; Receptors, IgG/biosynthesis ; Support, Non-U.S. Gov't ; Temperature ; Tetradecanoylphorbol Acetate/pharmacology ; Time Factors

This study was purposed to verify the binding part of human complement C3 to complement receptor III (CRIII) in monocytes, the peptide rC3B, including the binding-site, was expressed, purified and identified. rC3B, the binding part of human complement C3 to CRIII, was selected by computer-aided modeling and summarizing researches published. Then, rC3B gene fragment was amplified by PCR, and cloned into prokaryotic vector pQE30a. The fusion protein rC3B was expressed in E.coli M15 and purified by Ni(2+)-chelating affinity chromatography. The activity of rC3B was identified by Western blot and adherence assay with monocytes. The results showed that rC3B fragment was obtained, and a prokaryotic expression vector pQE30-rC3B was constructed. rC3B was efficiently expressed and purified. In Western blot, the target protein showed the activity of binding with C3 antibody, while the purified protein showed the activity of adherence with monocytes. It is concluded that the recombinant C3B was obtained and identified, and this study lay the basis for the further functional analysis of C3.
Cloning, Molecular ; Complement C3 ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Macrophage-1 Antigen ; genetics ; metabolism ; Receptors, Complement 3b ; biosynthesis ; genetics ; isolation & purification ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification

Effect of M. tuberculosis infection was studied on the expression of intercellular adhesion molocule-1 (ICAM-1) and Mac-1 markers on murine peritoneal macrophages. Intraperitoneal administration of M. tuberculosis resulted in a marked increase in the proportion of Mac-1+ cells whereas the proportion of ICAM-1+ cells declined sharply 4 h post infection. Absolute numbers of Mac-1+ and ICAM-1+ cells however increased at all time points after the infection. Comparison of kinetics of changes observed in Mac-1+ and ICAM-1+ cell populations with differential leukocyte counts in peritoneal cells indicated that these alterations could be due to cellular influx, especially that of neutrophils, or up regulation of these markers on macrophages and other peritoneal cells. In adherent peritoneal macrophages infected in vitro with M. tuberculosis, proportion of Mac-1+ and ICAM-1+ cells increased markedly within 24 h of infection. Mean expression of these markers on per cell basis also increased significantly. Similar results were obtained by using RAW 264.7 mouse macrophage cell line, suggesting that the enhanced expression of Mac-1 and ICAM-1 markers was a direct effect of M. tuberculosis infection and not mediated by contaminating cell types present in adherent macrophage preparations. Mac- 1 and ICAM-1 expression was further studied on macrophages that had actually engulfed M. tuberculosis and compared with bystander macrophages without intracellular M. tuberculosis. For this purpose M. tuberculosis pre-stained with DilC18 fluorescent dye were used for infecting adherent peritoneal macrophages. Mac-1 and ICAM-1 expression on gated DilC18 positive and negative cell populations was analyzed. Our results indicate that the expression of Mac-1 and ICAM- 1 markers was significantly enhanced on all macrophages incubated with M. tuberculosis but was more pronounced on macrophages with internalized mycobacteria. Taken together, our results suggest that the expression of Mac-1 and ICAM-1 markers is significantly up regulated
Animals ; Biological Markers/analysis/metabolism ; Cells, Cultured ; Intercellular Adhesion Molecule-1/analysis/*biosynthesis ; Macrophage-1 Antigen/analysis/*biosynthesis ; Macrophages, Peritoneal/*immunology/*microbiology ; Mice ; Mice, Inbred C57BL ; *Mycobacterium tuberculosis ; Peritoneum/microbiology ; Phagocytosis/physiology ; Research Support, Non-U.S. Gov't ; Tuberculosis/*immunology ; Up-Regulation

This study was aimed to investigate and compare the anti-leukemic effect mediated by dendritic cells (DC) derived from multidrug resistant (MDR) leukemia K562/A02 cells with high expression of p-glycoprotein (P-gp) and sensitive K562 cells. Multidrug resistant K562/A02 cell line and sensitive K562 cell line from chronic myeloid leukemia (CML) were induced for differentiating to DC in complete RPMI 1640 culture medium supplemented with GM-CSF (1 000 U/ml), IL-4 (500 U/ml) and TNF-alpha (100 ng/ml) for 14 days. The morphologic features of DC were observed by means of optical microscopy and the phenotype of DC was detected by flow cytometry. T-cell stimulating activity was determined by allogeneic lymphocyte reaction (allo-MLR). Cytotoxic activity was measured by MTT assay. The results indicated that DC derived from K562/A02 cells and K562 cells similarly showed the typical morphology of dendritic cell and expressed the surface differentiation antigens and costimulatory molecules CD1a, CD83, HLA-DR, CD80 and CD86 of DC. In allo-MLR, K562/A02-DC had a higher capacity to induce lymphocyte proliferation, compared with K562-DC (P < 0.05). K562/A02-DC and K562-DC could similarly generate specific cytotoxic activity against K562/A02 cells or K562 cells respectively, but low reactivity against HL-60 cells. More importantly, the cytotoxic activity mediated by K562/A02-DC was stronger than that by K562-DC against K562/A02 cells or HL-60/VCR cells (P < 0.01, respectively). It is concluded that functional DC can be differentiated from multidrug resistant leukemia K562/A02 cells as well as sensitive K562 cells in the presence of GM-CSF, IL-4 and TNF-alpha. Especially, DC derived from K562/A02 cells can induced a p-glycoprotein specific anti-leukemic immunity.
ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; Antigens, CD ; analysis ; Antigens, CD1 ; analysis ; B7-1 Antigen ; analysis ; B7-2 Antigen ; analysis ; Cell Differentiation ; drug effects ; immunology ; Cytotoxicity, Immunologic ; Dendritic Cells ; cytology ; immunology ; metabolism ; Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Flow Cytometry ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Immunoglobulins ; analysis ; Interleukin-4 ; pharmacology ; K562 Cells ; Leukemia ; immunology ; pathology ; Membrane Glycoproteins ; analysis ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the phosphorylation intensity of MAPK pathway molecular Erk1/2 and the proliferation of prostate cancer cell line PC-3M.

METHODSFlow cytometry and RT-PCR were employed to study the ratio of different cell cycles and phases, respectively, before and after GM-CSF stimulation. Erk1/2 phosphorylation intensity was examined by Western blot simultaneously.

RESULTSThe rate of PC-3M cells at S and G2/M stages and the expression intensity of Ki-67 increased after GM-CSF incubation in a dose-dependent manner. The phosphorylation intensity of Erk1/2 increased remarkably after stimulation with GM-CSF.

CONCLUSIONThe intensification of Erk1/2 phosphorylation is one important molecular mechanism of the proliferation of hormone-independent prostate cancer.

Cell Line, Tumor ; Cell Proliferation ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Ki-67 Antigen ; biosynthesis ; Male ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; physiology ; Neoplasms, Hormone-Dependent ; metabolism ; pathology ; physiopathology ; Phosphorylation ; Prostatic Neoplasms ; metabolism ; pathology ; physiopathology ; Signal Transduction ; drug effects