Antigen-loaded dendritic cells triggers a specific cytotoxic T lymphocytes immune response against hepatocellular carcinoma: in vitro study.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the common malignancies, characterized by poor response to conventional therapeutic options. Immunotherapy with dendritic cells (DCs)-vaccines is one of the most successful strategies used for the treatment of HCC. However, the methods applied in the preparation of antigen-loaded DCs are important factors for optimization of DCs vaccines. PURPOSE: The present study was conducted to investigate the effect of HCC-whole tumor cell lysate prepared using rapid repetitive freeze-thaw cycles on the immunogenicity of DCs and evaluate the ability of whole tumor cell lysate-pulsed DCs vaccine to induce a specific cytotoxic T lymphocytes (CTLs) response against HepG2 cell line. METHODS: Immature DCs generated from peripheral blood monocytes were randomized into two groups: control DCs and whole tumor cell lysate-pulsed DCs. Phenotypic analysis of the DCs' cell maturation marker CD83 and co-stimulatory molecule CD86 was performed. HCC-specific cytotoxic activity of CD8+ CTLs was measured in vitro. RESULTS: Loading of DCs with necrotic whole cell lysate resulted in non-significant changes in DCs' expression of CD83, but a significant increase in expression of CD86. In addition, CD8+ CTLs stimulated with whole tumor cell lysate-pulsed DCs showed a high cytotoxic activity that specifically attack HepG2 cells. CONCLUSION: Our findings indicated that pulsation of DCs with whole tumor cell lysate prepared by repetitive freeze-thaw cycles could efficiently enhance the ability of DCs to induce proliferation and clonal expansion of CD8+ CTLs. Data herein, also indicated that whole tumor cell lysate-pulsed DCs triggers a specific CD8+ CTLs against HCC tumor cells.

In vitro and in vivo studies of the immunomodulatory effect of Echinacea purpurea on dendritic cells.

BACKGROUND: Extracts of Echinacea have been used traditionally for the treatment of diverse types of infections and wounds. They have become very familiar immunostimulant herbal medicine. However, the specific immunomodulatory effect of Echinacea remains to be elucidated. AIM: In our study, the effect of Echinacea purpurea extract on the generation of immature DCs from monocytes was described, as well as its effect on DC differentiation. In addition, an in vivo experiment was conducted to investigate whether treatment of mice with extracts derived from E. purpurea has immunomodulatory effect on murine splenic DCs. METHODS: Immature DCs were generated by incubating peripheral blood monocytes with cytokine cocktail (GM-CSF + IL-4) and matured by tumor necrosis factor-α (TNF-α). The cells were randomized to 5 groups to investigate E. purpurea effect in different stages. Phenotypic analysis of cell marker CD83-expressed on DCs was performed by flow cytometry. Mice were randomly divided into 3 groups; control, E. purpurea treated and E. purpurea-TNF-α treated group. The murine splenic DCs were isolated and phenotyped for CD83 and CD11c by flow cytometry. RESULTS: Treatment of monocytes with E. purpurea prior to addition of the maturation factor TNF-α resulted in a significant decrease in the yield of DC expressing CD83. On the other hand, immature DCs generated in the culture in the presence of GM-CSF and IL-4, when treated simultaneously with E. purpurea and TNF-α, exhibited an insignificant change in the yield of CD83-expressing DCs compared with untreated control. The in vivo experiments showed that splenic DCs obtained from mice treated with E. purpurea with or without TNF-α did not exhibit significant changes in CD83 or CD11c compared with those obtained from control mice. CONCLUSION: Our findings suggest that the immunomodulatory mechanisms of E. purpurea impact generation fate of DCs rather than differentiation stages. The results obtained in the in vivo study utilizing murine splenic DCs supported those observed in vitro.

Effect of dimethyl diphenyl bicarboxylate on normal and chemically-injured liver.

This study evaluates the effect of DDB on normal and chemically-injured liver. When given to normal rats DDB had no significant effect on liver enzymes, but in chemically-injured rats there was a significant decrease in the elevated levels of liver enzymes. DDB produced a significant increase in reduced glutathione, glutathione peroxidase and glutathione reductase, and a significant decrease in malondialdehyde and glucose-6-phosphate dehydrogenase in both normal and chemically-injured liver. The histopathology examinations showed a slight improvement with DDB administration. DDB has a beneficial effect on liver enzymes and possesses significant antioxidant properties in normal and chemically-injured liver, and may therefore be clinically useful in treating chronic viral hepatitis B in humans.

Effect of dimethyl diphenyl bicarboxylate on normal and chemically-injured liver

This study evaluates the effect of DDB on normal and chemically-injured liver. When given to normal rats DDB had no significant effect on liver enzymes, but in chemically-injured rats there was a significant decrease in the elevated levels of liver enzymes. DDB produced a significant increase in reduced glutathione, glutathione peroxidase and glutathione reductase, and a significant decrease in malondialdehyde and glucose-6-phosphate dehydrogenase in both normal and chemically-injured liver. The histopathology examinations showed a slight improvement with DDB administration. DDB has a beneficial effect on liver enzymes and possesses significant antioxidant properties in normal and chemically-injured liver, and may therefore be clinically useful in treating chronic viral hepatitis B in humans