OBJECTIVETo investigate immunomodulatory effect of Astragalus polysaccharides (APS) on IL-12-secreting dendritic cell (DC) subset CD11c(high)CD45RB(low) DC.

METHODSSpleen CD11c(high)CD45RB(low) DC and CD4(+)T lymphocytes in BALB/c mice were purified by magnetic beads sorting, and were treated with 0 (as control), 50, 100, 200 µg/mL APS. Immunofluorescence staining and flow cytometry were used to determine expressions of CD11c(high)CD45RB(low) DC surface molecules, including CD40, CD80, CD86, I-A/E, and Toll-like receptor (TLR) 4. IL-12 level in CD11c(high)CD45RB(low) DC culture supernatant was determined by ELISA. The CD4(+) T lymphocytes were divided into: normal control group, non-stimulation group (CD4(+)T lymphocytes cocultured with APS-unstimulated CD11c(high)CD45RB(low) DC), high-dose APS stimulation group (CD4(+)T lymphocytes cocultured with 200 µg/mL APS-stimulated CD11c(high)CD45RB(low) DC), high-dose APS stimulation+antibody 1 group (CD4(+)T lymphocytes cocultured with 200 µg/mL APS-stimulated CD11c(high)CD45RB(low) DC and IL-12 antibody), high-dose APS stimulation+ antibody 2 group (CD4(+)T lymphocytes cocultured with 200 µg/mL APS-stimulated CD11c(high)CD45RB(low) DC and IL-12 antibody isotype). Proliferation ability of CD4(+) T lymphocytes was determined with MTT method. IL-4 level as well as IFN-γ level in CD4(+)T lymphocyte culture supernatant was determined by flow cytometry. Data were processed with one-way analysis of variance.

RESULTSCompared with those in control, the expressions of CD11c(high)CD45RB(low) DC surface molecules (except for CD86) on CD11c(high)CD45RB(low) DC surface, as well as IL-12-secreting level with dose-dependence were increased in cells stimulated with 50, 100, 200 µg/mL APS. Proliferation ability of CD4(+)T lymphocytes in high-dose APS stimulation group was higher as compared with that in non-stimulation group (F = 13.438, P < 0.05). IFN-γ level in high-dose APS stimulation group \[(2784 ± 137) pg/mL\] was higher than that in non-stimulation group \[(1952 ± 101) pg/mL, F = 12.177, P < 0.05\]. IL-4 level in high-dose APS stimulation group was (172 ± 20) pg/mL, which was lower than that in non-stimulation group \[(193 ± 19) pg/mL, F = 11.963, P < 0.05\]. Proliferation ability of CD4(+) T lymphocytes, IFN-γ level, and IL-4 level in high-dose APS stimulation + antibody 1 group were all ameliorated when compared with those in non-stimulation group; while levels of the 3 indexes in high-dose APS stimulation + antibody 2 group were similar to those in high-dose APS stimulation group.

CONCLUSIONSAPS can activate IL-12-producing CD11c(high)CD45RB(low) DC, and further induce the activation of immune function of T lymphocyte with shifting of Th2 to Th1 in vitro. APS can enhance the immune response via promoting the phenotypic and functional maturation of CD11c(high)CD45RB(low) DC.

Animals ; Astragalus Plant ; chemistry ; Cell Differentiation ; Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; secretion ; Interleukin-12 ; metabolism ; Mice ; Mice, Inbred BALB C ; Polysaccharides ; pharmacology ; Th1 Cells ; immunology

This study was to establish the method of purifying heat shock protein GP96 from K562 cells and explore the differentiation and function of human DC influenced by heat shock prolein (HSP). Using ammonium sulfate precipitation, conA-sepharose affinity chromatography and DEAE-sephacel anion exchange chromatography GP96 from K562 cells lysate was isolated and purified. The identification of the purified protein was controlled by Western blot with anti-human GP96 IgG. Human dendritic cell derived from peripheral blood mononuclear cell were cultured with purified GP96. The phenotype changes of DC were analyzed by flow cytometry and MLR was detected by MTT. The results showed that 60-80 microg GP96 was purified successfully from 1 x 10(10) K562 cells. DC stimulated with HSP-GP96 had higher expression rates of CD83, CD86, HLA-DR and lower expression rates of CD1a and had stronger ability to induce T cells proliferation. It is concluded that heat shock protein GP96 can be isolated and purified from K562 cells and could induce maturation of dendritic cell. HSP-DC vaccine show stronger ability to induce T cell proliferation than DC.
Antigens, Neoplasm ; isolation & purification ; pharmacology ; Cancer Vaccines ; immunology ; Cell Differentiation ; drug effects ; Dendritic Cells ; cytology ; drug effects ; immunology ; Humans ; Immunophenotyping ; K562 Cells ; chemistry

OBJECTIVETo explore the possibility of cell-medicated immune response induced with heat shock protein 70 (HSP70)-HBsAg protein complex in vitro.

METHODSHSP70-HBsAg complex was reconstituted in vitro which was injected into mice in order to observe that whether HSP70-HBsAg would stimulate humoral and cellular immune responses. HSP70, HSP70-HBsAg complex and HBsAg were used to activate the dentritic cell (DC) individually, which would initiate homogeneic T lymphocyte to transform to cytotoxic T lymphocyte (CTL). The cytotoxicity of CTL was detected with MTT assay.

RESULTSHSP70-HBsAg complex elicited both humoral and cellular immune responses against HBsAg in mice. Specific CD8+ CTL response was readily induced by HSP70-HBsAg complex and HBsAg, especially the former.

CONCLUSIONSHSP70-HBsAg complex is immunogenic and HSP70 can lead to great efficient CTL response. And HSP70-HBsAg complex may be used as a protein vaccine for immunotherapy for chronic hepatitis B.

Animals ; Cells, Cultured ; Dendritic Cells ; immunology ; secretion ; Female ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Hepatitis B Surface Antigens ; genetics ; immunology ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Mycobacterium tuberculosis ; chemistry ; Peptides ; chemistry ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo investigate the feasibility of reduction in tumor antigen peptide dose by dendritic cell (DC)-presenting so as to elucidate the characteristics of modifying DC by heat shock protein (Hsp70) and antigen peptide.

METHODSAntigen peptide bound to Hsp70 was used to modify DC in vitro. The metabolism of the modified DC and the cytokine secreted thereby was determined. Then the activation of lymphocytes by the modified DC and Hsp70-H22 peptide was tested. The cytotoxicity of the activated lymphocytes to H22 tumor cells and the inhibition of tumor in mice by DC injection and Hsp70-H22 peptide was tested.

RESULTS0.15 micro g of H22 peptide bound to Hsp70 could mature 2 x 10(5) DC. 4 x 10(3) matured DC could activate 2 x 10(6) lymphocytes. The same amount of lymphocyte could be activated to produce similar cytotoxicity to tumor cells by either DC modified by 0.003 micro g of peptides bound with Hsp70 or by direct stimulation with 0.15 micro g of peptides bound to Hsp70. The dose of peptide could be reduced to 1/50 if the modified DC injection was used instead of direct Hsp70-peptide injection. Peptide from the normal hepatocytes, if bound to Hsp70, could not mature DC, nor could it activate lymphocytes through DC.

CONCLUSIONThe dose of Hsp70-H22 peptides can be reduced significantly by DC-presenting to activate lymphocytes. Peptides from normal cells, being unable to activate the lymphocytes by either Hsp70-presenting or DC-presenting, have little to offer in the induction of autoimmunity.

Animals ; Antigens, Neoplasm ; immunology ; Dendritic Cells ; immunology ; Disease Models, Animal ; HSP70 Heat-Shock Proteins ; chemistry ; immunology ; therapeutic use ; Immunity ; Lymphocyte Activation ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Neoplasms, Experimental ; prevention & control ; Peptides ; chemistry ; immunology ; therapeutic use ; Tumor Cells, Cultured

Due to their high immunostimulatory ability as well as the critical role they play in the maintenance of self-tolerance, dendritic cells have been implicated in the pathogenesis of autoimmune diseases. The non-obese diabetic (NOD) mouse is an animal model of autoimmune type 1 diabetes, in which pancreatic beta cells are selectively destroyed mainly by T cell-mediated immune responses. To elucidate initiation mechanisms of beta cell-specific autoimmunity, we attempted to generate bone marrow-derived dendritic cells from NOD mice. However, our results showed low proliferative response of NOD bone marrow cells and some defects in the differentiation into the myeloid dendritic cells. NOD dendritic cells showed lower expressions of MHC class II, B7-1, B7-2 and CD40, compared with C57BL/6 dendritic cells. In mixed lymphocyte reactions, stimulatory activities of NOD dendritic cells were also weak. Treatment with LPS, INF-gamma and anti-CD40 stimulated NOD dendritic cells to produce IL-12p70. The amount of IL-12, however, appeared to be lower than that of C57BL/6. Results of the present study indicated that there may be some defects in the development of NOD dendritic cells in the bone marrow, which might have an impact on the breakdown of self tolerance.
Animal ; Autoimmune Diseases/pathology ; Autoimmune Diseases/immunology ; Bone Marrow Cells/pathology* ; Bone Marrow Cells/immunology* ; Bone Marrow Cells/chemistry ; Cell Differentiation/immunology ; Cell Differentiation/drug effects ; Dendritic Cells/pathology* ; Dendritic Cells/immunology* ; Dendritic Cells/chemistry ; Diabetes Mellitus, Insulin-Dependent/pathology* ; Diabetes Mellitus, Insulin-Dependent/immunology ; Enzyme-Linked Immunosorbent Assay ; Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology ; Interleukin-12/analysis ; Interleukin-4/pharmacology ; Lipopolysaccharides/pharmacology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Inbred NOD ; Obesity

Animals ; Antigens, Neoplasm ; chemistry ; immunology ; Cancer Vaccines ; chemistry ; therapeutic use ; Cell Line, Tumor ; CpG Islands ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; metabolism ; Humans ; In Vitro Techniques ; Lactic Acid ; chemistry ; Leukemia ; immunology ; therapy ; Lymphocytes ; cytology ; immunology ; Nanoparticles ; chemistry ; Peptides ; chemistry ; immunology ; therapeutic use ; Polyglycolic Acid ; chemistry ; Polylactic Acid-Polyglycolic Acid Copolymer ; WT1 Proteins ; chemistry ; immunology

OBJECTIVETo elucidate the immunomodulatory mechanism of phenylethanoid glycosides from the seeds of Plantago asiatica by testing its effects on the maturing of murine bone marrow derived dendritic cells (DCs).

METHODMonocytes generated from bone marrow of Balb/cj mouse were cultured for 6 days in complete RPMI 1640 medium containing 10% FBS, rmGM-CSF and rmIL-4.50 mg x L(-1) acteoside or isoacteoside was added to cells on day 6 of culture for 24 h. The surface molecules expression level of DCs and their phagocytose ability were analysis by flow cytometry.

RESULTBoth acteoside and isoacteoside could increase the expression of CD11c, CD86, MHC II and CD80 on DCs surface. The ability of unstimulated DCs to uptake FITC-dextran was higher than that of phenylethanoid glycosides or LPS treated DCs.

CONCLUSIONBoth acteoside and isoacteoside could induce maturation of murine dendritic cells.

Animals ; B7-1 Antigen ; immunology ; metabolism ; B7-2 Antigen ; genetics ; immunology ; Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; Gene Expression ; drug effects ; Glycosides ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; Phagocytosis ; drug effects ; Plant Extracts ; pharmacology ; Plantago ; chemistry ; Seeds ; chemistry

Dendritic cells have been known as a member of strong innate immune cells against infectious organelles. In this study, we evaluated the cytokine expression of splenic dendritic cells in chronic mouse toxoplasmosis by tissue cyst-forming Me49 strain and demonstrated the distribution of lymphoid dendritic cells by fluorescence-activated cell sorter (FACS). Pro-inflammatory cytokines, such as IL-1alpha, IL-1beta, IL-6, and IL-10 increased rapidly at week 1 post-infection (PI) and peaked at week 3 PI. Serum IL-10 level followed the similar patterns. FACS analysis showed that the number of CD8alpha+/CD11c+ splenic dendritic cells increased at week 1 and peaked at week 3 PI. In conclusion, mouse splenic dendritic cells showed early and rapid cytokine changes and may have important protective roles in early phases of murine toxoplasmosis.
Animals ; Antigens, CD11c/analysis ; Antigens, CD8/analysis ; Cytokines/*blood/*secretion ; Dendritic Cells/chemistry/*immunology ; Disease Models, Animal ; Flow Cytometry ; Mice ; Mice, Inbred BALB C ; Rodent Diseases/immunology ; Spleen/*immunology ; Time Factors ; Toxoplasmosis, Animal/*immunology

Sparganosis is a tissue invading helminthiasis infecting intermediate hosts, including humans. Strong immune responses are expected to occur in early phases of infection. Thus, we investigated cytokine expressions in splenic dendritic cells and in sera after experimental infection of mice. In splenic dendritic cells, TNF-alpha and IL-1beta expression peaked at week 1 and week 3 post-infection (PI), respectively, and also early phase (week 2 PI) depressed cytokine expression was noticed. Serum IL-1beta concentration increased significantly at week 2 PI and peaked at week 6 PI, and that of TNF-alpha peaked at week 6 PI. These results showed that pro-inflammatory cytokines, TNF-alpha and IL-1beta, are chronologically regulated in mouse sparganosis.
Animals ; Dendritic Cells/*immunology ; Disease Models, Animal ; Interleukin-1beta/*blood/*secretion ; Mice ; Mice, Inbred BALB C ; Rodent Diseases/immunology ; Serum/chemistry ; Sparganosis/*immunology ; Spleen/*immunology ; Tumor Necrosis Factor-alpha/*blood/*secretion

BACKGROUND AND OBJECTIVEAs a prospective vaccine carrier, nanoparticles can protect antigens from degradation and enhance immune response. This study prepared nanovaccines with MAGE-3-derived CD4+-CD8+T cell epitope peptides, and investigated its character and antitumor effects on transplanted gastric cancer in mice.

METHODSWe adopted the self-assembly method to prepare peptide/chitosan conjugated with deoxycholic acid (chitosan-deoxycholic acid) nanoparticles. We observed the appearance of the chitosan-deoxycholic acidnanoparticles through a transmission electron microscope (TEM) and analyzed the peptide content and its release pattern by fluorescence spectrophotometry. We observed tumor-suppression efficacy in vivo through animal experiments.

RESULTSWe successfully prepared nanoparticles with MAGE-3 peptide antigen, and its encapsulation efficiency and loading level were about 37% and 17.0%, respectively. These nanoparticles presented a delayed release pattern in phosphate buffered saline (PBS) at pH 7.4, and the full release time was about 48 h. In 2 mg/mL lysozyme, the nanoparticles showed a sudden release, and the full release time was about 24 h. ELISPOT and cytotoxic experiments showed that the MAGE-3 peptide loaded nanoparticles could stimulate immune response in vivo and could generate MAGE-3-targeted cytotoxic T lymphocytes (CTLs), and kill MAGE-3-specific tumor cells. Tumor suppression experiments showed that the regression ratio of the peptide-loaded nanoparticles group was 37.81%.

CONCLUSIONSMAGE-3 peptide/chitosan-deoxycholic acidvaccine-loaded nanoparticles can stimulate antitumor immune response in vivo and can regress the growth of mouse forestomach carcinoma cell line MFC.

Animals ; Antigens, Neoplasm ; chemistry ; immunology ; Cancer Vaccines ; administration & dosage ; Cell Line, Tumor ; Chitosan ; chemistry ; Dendritic Cells ; immunology ; Deoxycholic Acid ; chemistry ; Drug Carriers ; chemistry ; Epitopes, T-Lymphocyte ; immunology ; Male ; Mice ; Nanoparticles ; Neoplasm Proteins ; chemistry ; immunology ; Neoplasm Transplantation ; Stomach Neoplasms ; pathology ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Burden