Vaccination with dendritic cells pulsed with hepatitis C pseudo particles induces specific immune responses in mice

Figure 1 Fluorescence activated cell sorting analysis of bone-marrow derived dendritic cell of BALB/c mice, identified by expression of CD11c, after 7 d of maturation, followed by incubation with different agents. Column one shows the negative control, columns two and three show dendritic cell (DC) incubated with only lipopolysaccharide (LPS) or hepatitis C virus pseudo particles (HCVpp) with the co-stimulator LPS, respectively, and column four shows DC incubated with HCVpp only. Expression of the surface markers CD86 and CCR7 after pulsion of the DC with HCVpp and/or LPS is shown in percent.

Figure 2 Induction of anti-E1 and anti-E2 antibodies following s. c. immunization of BALB/c mice. All animals specifically vaccinated developed specific antibodies. Highest antibody titers were observed in the two groups of mice which received the dendritic cell (DC) based vaccines. The negative control with phosphate buffered saline showed only very little unspecific binding. PepSets™ Pools 1-9 spanning the E1 and E2 protein of the hepatitis C virus (HCV) Con1 isolate showed considerably lower binding activity in the treatment groups, whereas the negative control groups did not show any differences between the different antigens. Through serial dilutions OD was calculated for HCV pseudo particles (HCVpp) group to be OD 1755, for the DC + HCVpp group OD 2013 and for the DC + HCVpp+ lipopolysaccharide (LPS) group OD 1944. For significance, NaCl groups were compared with DC + HCVpp groups. Pool 1-3 covers most of the E1 protein, pool 4 comprises the last 24 amino acids of the E1 protein and the first 32 amino acids of the E2 protein, and pool 5-9 enclose the rest of the E2 protein. NaCl: Saline; 293T: Cell culture supernatant of 293T-cells. Results are given as means of quadruplicate measurements of eight mice each group. ^aP < 0.05, ^bP < 0.001.

Figure 3 Antigen specific T-cell responses detected by interferon-gamma enzyme-linked immunosorbent spot test. Immune responses were induced by vaccination of different BALB/c mice with different agents. The two negative control groups were vaccinated with saline or 239T supernatant. The third group were mice vaccinated with hepatitis C virus pseudo particles (HCVpp) only. The treatment groups were mice vaccinated with dendritic cell (DC) prior pulsed with HCVpp with or without lipopolysaccharide (LPS). For detection of specific T-cells, spleenocytes were incubated with HCVpp or pooled overlapping peptides covering the E1 and E2 proteins of the HCV Con1 sequence. Convacalin A (ConA) was used as a positive control. Best results were achieved in the group of mice vaccinated with DC prior pulsed with HCVpp and LPS as an adjuvant. For significance HCVpp groups were compared with DC + HCV + LPS groups. NaCl: Saline; 293T: Cell culture supernatant of 293T-cells; NS: Not significant. Results are shown as mean values of 8 mice each group. ^aP < 0.05, ^bP < 0.001.