Toxoplasma gondii has been shown to result in life-threatening encephalitis in immunocompromised patients after reactivation of dormant parasites. In order to obtain information on immune responses related to this phenomenon, BALB/c mice were infected with 25 cysts of the 76K strain of T. gondii, then, treated orally with dexamethasone (Toxo/Dexa-treated group) in order to reactivate the chronic toxoplasmosis. None of the T. gondii-infected mice died during the experimental periods, whereas the Toxo/Dexa-treated mice evidenced a significant attenuation of survival periods. Toxoplasma-specific IgG2a, IgA and IgM titers in sera were significantly depressed in the Toxo/Dexa-treated mice; however, the IgG1 sera titers were similar to those seen in the Toxoplasma-infected mice. The percentages of CD4+ and CD8 alpha + T cells in the Toxo/Dexa-treated mice were significantly reduced 2 weeks after dexamethasone treatment. IFN-gamma and IL-10 production levels in the Toxo/Dexa-treated mice were depressed significantly, whereas IL-4 production was increased temporarily. The expression levels of the Toxoplasma-specific P30 and B1 genes were found to have been increased in the Toxo/Dexa-treated mice in comparison with the Toxoplasmainfected mice. Collectively, the findings of this study demonstrate that reactivation of murine toxoplasmosis as the result of dexamethasone treatment induced a depression in Th1 immune responses, whereas Th2 immune responses were not significantly influenced.
Toxoplasmosis/*immunology/parasitology ; Toxoplasma/*immunology ; Th2 Cells/immunology ; Th1 Cells/immunology ; Mice, Inbred BALB C ; Mice ; Immunoglobulins/*biosynthesis/immunology ; Female ; Dexamethasone/*pharmacology ; Cytokines/*biosynthesis ; Antibodies, Protozoan/*biosynthesis/immunology ; Animals

The present study was undertaken to produce monoclonal antibodies (MAbs) against immunoglobulin (Ig) purified from black rockfish (Sebastes schlegeli Higendorf) serum using protein A, mannan binding protein, and goat IgG affinity columns. These three different ligands were found to possess high affinity for black rockfish serum Ig. All of the Igs purified eluted at only 0.46 M NaCl concentration in anion exchange column chromatography and consisted of two bands at 70 kDa and 25 kDa in SDS-PAGE; they also had similar antigenicity for MAbs to Ig heavy chain in immunoblot assays. Therefore, black rockfish Ig is believed to exist as a single isotype within serum. The MAbs produced against Ig heavy chain reacted specifically with spots distributed over the pI range from 4.8 to 5.6 with a molecular weight of 70 kDa on two dimensional gel electrophoresis immunoblot profiles.
Animals ; Antibodies, Monoclonal/*biosynthesis/immunology ; Chromatography, Affinity/veterinary ; Electrophoresis, Gel, Two-Dimensional/veterinary ; Immunoblotting/veterinary ; Immunoglobulin Heavy Chains/immunology ; Immunoglobulin Light Chains/immunology ; Immunoglobulins/blood/*immunology ; Perciformes/blood/*immunology

To investigate the influence and mechanisms of CD47 engagement by its soluble mAb B6H12 on the maturation and function of cultured dendritic cells (DCs), monocyte-derived DCs were propagated in granulocyte-macrophage colony stimulating factor (GM-CSF) combined with lipopolysaccharide (LPS) and interleukin (IL)-4, in the presence or absence of soluble anti-CD47 monoclonal antibodies (anti-CD47 mAbs, B6H12). The characteristic morphology of DCs was identified by using the transmission electron microscopy. Flow cytometry was used to detect the cell surface phenotypes. The concentration of IL-12 P70 in supernatant was measured by ELISA. The antigen-presenting functions of DCs were determined in one-way mixed leukocyte reaction by BrdU-ELISA. Electrophoretic mobility shift assay (EMSA) was applied to examine the activity of NF-kappaB. The results indicated that the anti-CD47 mAbs markedly suppressed the expression of CD80, CD86, CD83, CD1a and HLA-DR on the surface of DCs (P < 0.05). The data of the mixed leukocyte reaction and IL-12 P70 production were consistent with the results by flow cytometry (P < 0.01). Pre-exposure to B6H12 mAb during the development of DCs resulted in a dramatic depletion of the DNA binding activity of NF-kappaB toward nucleus protein. Moreover, such an inhibition effect seemed to be dose dependent. In conclusion, the soluble mAb B6H12 inhibits the expression of the costimulatory molecules and MHCII molecules on the DCs. The antigen-presenting function of DCs was also impaired by B6H12. And these modulations are closely related with the depletive DNA binding activity of NF-kappaB. It is suggested that the soluble B6H12 exerts a negative effect on the maturation and function of in vitro cultured DCs due to inhibition of NF-kappaB binding activity.
Antibodies, Monoclonal ; immunology ; pharmacology ; Antigens, CD ; biosynthesis ; Antigens, CD1 ; biosynthesis ; B7-1 Antigen ; biosynthesis ; B7-2 Antigen ; biosynthesis ; CD47 Antigen ; immunology ; Cell Size ; drug effects ; Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; metabolism ; Electrophoretic Mobility Shift Assay ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; HLA-DR Antigens ; biosynthesis ; Humans ; Immunoglobulins ; biosynthesis ; Interleukin-12 ; metabolism ; Membrane Glycoproteins ; biosynthesis ; NF-kappa B ; metabolism ; Oligonucleotides ; metabolism ; Protein Binding

The dietary effect of conjugated linoleic acid (CLA) on the response of the immunoglobulin (serum and tissue) production in Balb/C mice was examined at three doses: 0 %(control), 0.5% and 1.5%. The combination effects of CLA with vitamin ADE or selenium also were investigated. CLA at 0.5% increased serum immunoglobulin A, G, mesenteric lymp node (MHN) and gut luminal IgA (secretory IgA) levels. However, 1.5% CLA decreased SIgG slightly. CLA both alone and combined with vitamin ADE and selenium did not affect serum IgE. The levels of immunoglobulin concentration in the 0.5% CLA group were higher than those in the1.5% CLA group. The level of serum IgG in 1.5% CLA combined with selenium was maintained at the same level as that of control. It is considered that over- doses of CLA (1.5%) even depressed the production of immunoglobulin but selenium and/or vitamin inhibited this activity to a certain extent.In this study, dietary CLA increased immunoglobulin production in a dose-dependent manner. Vitamin ADE and Selenium combined with CLA also increased the immunoglobulin production response except serum IgE.
Animals ; Antioxidants/*pharmacology ; Dose-Response Relationship, Drug ; Drug Therapy, Combination ; Immunoglobulins/*biosynthesis/blood/immunology ; Intestines/drug effects/immunology ; Linoleic Acid/*pharmacology ; Lymph Nodes/drug effects/immunology ; Male ; Mice ; Mice, Inbred BALB C ; Selenium/*pharmacology ; Vitamin A/*pharmacology

OBJECTIVEThe expression of CD25, CD45RA, CD45RO on umbilical cord blood mononuclear cells (CBMCs) and CD3(+) T lymphocytes was investigated to explore the mechanism of immunosuppressive effects of intravenous immunoglobulin on neonatal immune function.

METHODSUmbilical cord blood mononuclear cells and CD3(+) T lymphocytes isolated from 8 neonates were studied. The expression of CD25, CD45RA, CD45RO on umbilical cord blood mononuclear cells (CBMCs) and CD3(+) T lymphocytes induced with various stimuli of different combinations of IVIG and phytohemagglutinin (PHA) including (1) control group, (2) PHA activation group, (3) IVIG pre-inhibition group, (4) PHA pre-activation group, (5) PHA+IVIG group was measured with four-color immunofluorescence antibodies staining-flow cytometric technique. The results were also compared with peripheral blood mononuclear cells of 8 adults (PBMCs).

RESULTSIVIG inhibited the PHA-induced proliferation of CBMCs as reflected by the decreased expression of CD25 and CD45RO. The amounts of CD25(+) and CD4(+)CD45RO(+) CBMCs reached 77.52% +/- 2.31% and 64.29% +/- 3.09% after PHA use. But a decreased response in CD25(+) (7.66% +/- 1.20% and 7.78% +/- 1.46%) and CD4(+)CD45RO(+) CBMC (3.18% +/- 1.90% and 3.11% +/- 0.08%) was observed when IVIG was added in both IVIG pre-inhibition group and PHA+IVIG group. As compared with PBMCs, IVIG failed to induce the increase of the expression of CD45RA in CBMCs whereas CD45RA(+) PBMCs increased from 54.93% +/- 3.63% to 72.77% +/- 0.39% in IVIG pre-inhibition group. Moreover, IVIG inhibited the expression of CD25 and CD45RO on cord blood CD3(+) T lymphocytes no matter whether they were activated with PHA or not. The amounts of CD25(+) and CD4(+)CD45RO(+) CD3(+) T lymphocytes reached 97.92% +/- 2.19% and 80.41% +/- 5.57% after PHA use. But a decreased response in CD25(+) CBMCs (77.29% +/- 0.63%, 51.48% +/- 1.85% and 62.73% +/- 1.24%) and CD4(+)CD45RO(+) CD3(+) T lymphocytes (35.47% +/- 2.55%, 40.14% +/- 1.16% and 36.41% +/- 2.96%) was observed when IVIG was added in IVIG pre-inhibition group, PHA pre-activation group and PHA+IVIG group, and the degree of inhibition of IVIG on cord blood CD3(+) T lymphocytes was much lower than that of CBMCs.

CONCLUSIONSCord blood T lymphocytes activation was inhibited by IVIG through the inhibition of CD25(+) CBMCs expression and the prevention of transformation from CD4(+)CD45RA(+) cells into CD4(+)CD45RO(+) cells. This IVIG-mediated suppression of activation in cord blood T cells may be derived from the indirect effect of other immune cells or molecules other than the direct effects on T cells. IVIG failed to induce the increase of expression of CD45RA in CBMCs, which may be related to the fact that majority of CBMCs were CD45RA(+) cells, but this may not rule out that the immunosuppressive effect of IVIG could be accomplished by the increase of CD45RA(+) cells in adult peripheral blood mononuclear cells. The suppressive effect of IVIG on CD4(+)CD45RO(+) T lymphocytes may account for its inhibitory effect on immunoglobulin production of neonates' B cells. Considering that naïve CD45RA(+) cells dominate in neonates and IVIG can inhibit transformation from CD4(+)CD45RA(+) cells into CD4(+)CD45RO(+) cells, it is recommended that IVIG should be used properly in neonates, otherwise it may deteriorate their poor immune function especially when it is used for prophylaxis or as a treatment of neonatal non-infectious diseases, and its immunosuppressive action will increase the susceptibility of neonates to infection.

Adult ; CD3 Complex ; biosynthesis ; immunology ; Cell Survival ; drug effects ; Cells, Cultured ; Female ; Fetal Blood ; cytology ; immunology ; Flow Cytometry ; Humans ; Immunoglobulins, Intravenous ; administration & dosage ; adverse effects ; immunology ; Immunologic Factors ; adverse effects ; Immunosuppressive Agents ; administration & dosage ; adverse effects ; immunology ; Infant, Newborn ; Injections, Intravenous ; Interleukin-2 Receptor alpha Subunit ; biosynthesis ; immunology ; Leukocyte Common Antigens ; biosynthesis ; immunology ; Leukocytes, Mononuclear ; cytology ; drug effects ; immunology ; Lymphocytes ; cytology ; drug effects ; immunology ; Male

OBJECTIVETo study the effect and mechanism of the peripheral blood mononuclear cell (PBMC) invasion by HBV on artificial immunization in newborns.

METHODSFifty-two newborns of HBsAg positive mothers were immunized with HBIG (hepatitis B immunoglobulin) and HBVac (hepatitis B vaccine) and were followed up for 7 months. The newborns' HBV-DNA in serum and in the PBMCs was detected with nested-PCR; anti-HBs was tested with solid phase radioimmunoassay (SP-RIA). PBMCs isolated from newborn peripheral blood were incubated in the presence of PHA or purified HBsAg. Interleukin-2 (IL-2) level in culture supernatants of activated cells was detected by ELISA.

RESULTSThe failure rate of immunization was higher in infants with positive HBV-DNA in PBMCs than those with negative HBV-DNA (P < 0.05); IL-2 level in PBMC culture supernatants was lower in former than in the latter and in normal controls (P < 0.05). The level of IL-2 in the immunization failure newborns was lower than that in the successfully immunized newborns and in normal controls (P < 0.05).

CONCLUSIONSIntrauterine invasion of PBMCs by HBV is one of the important reasons for immunization failure in newborns. IL-2 production is closely related to the invasion of PBMCs by HBV, which may contribute to the failure of artificial immunization in newborns.

DNA, Viral ; blood ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B Vaccines ; adverse effects ; Hepatitis B virus ; isolation & purification ; physiology ; Humans ; Immunization ; adverse effects ; Immunoglobulins ; immunology ; Infant, Newborn ; Interleukin-2 ; biosynthesis ; blood ; Leukocytes, Mononuclear ; virology

OBJECTIVE: To investigate the tumor-suppression effect of PA combined with GM-CSF, TNF-alpha and IL-4 on cord blood mononuclear cells (CBMC). METHODS: The mononuclear cells were isolated from human umbilical cord blood and cultured with polyacttin A (PA), GM-CSF + TNF-alpha + IL-4 (GTI), and GTI + PA (GTIP) respectively. Six days later, surface antigen expression of the cultured cells, including CD1a and CD83, which were the specialized markers of dendritic cell (DC), were analyzed by immunohistochemistry technique. The CBMC were cultured with GTI for 24 h to enhance DC, then were added apoptotic/necrotic Hela/HepG2 tumor cells, and finally PA was co-cultured. The antitumor cytotoxicity of CBMC was measured by MTT assay. RESULTS: After the culture, CD1a and CD83 positive cell rates of the PA group inreased significantly, reaching (19.63 +/- 3.61)%, (9.28 +/- 4.31) % respectively, much higher than that of the control, but lower than that of the GTI group. The killing rate to the tumor cells of CBMC cultured with GTIP increased remarkably, much higher than the control, GTI and PA groups. After tumor antigens were added to the CBMC of GTIP group (GTIP + Tc), the killing rate increased. CONCLUSION PA not only promotes the proliferation and maturation of cord blood derived DC, but also improves the tumor-suppression effect of CBMC cultured with GTI.
Antigens, CD ; biosynthesis ; genetics ; Antigens, CD1 ; biosynthesis ; genetics ; Cells, Cultured ; Fetal Blood ; cytology ; Glycopeptides ; pharmacology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; HeLa Cells ; Humans ; Immunoglobulins ; biosynthesis ; genetics ; Immunotherapy ; Interleukin-4 ; pharmacology ; Leukocytes, Mononuclear ; drug effects ; immunology ; Liver Neoplasms ; pathology ; therapy ; Membrane Glycoproteins ; biosynthesis ; genetics ; Neoplasms ; therapy ; Tumor Cells, Cultured ; Tumor Necrosis Factor-alpha ; pharmacology

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