Modulation of Dendritic Cell Apoptosis and CD8⁺ Cytotoxicity by Histamine: Role of Protein Kinase C

Figure 3

Histamine increases the ability of DC to activate CD8⁺ cytotoxicity. Histograms show the cytotoxicity after 24 h (a) and 48 h (b) of in vitro coculture of OVA-immunized splenic mononuclear cells (5 × 10⁶) with OVA loaded-DC stimulated or not with HIS (1.25 × 10⁵). Bars represent the mean Cx percentage ± SE of 6 independent experiments. In (c), we show a representative in vitro Cx histogram plot. The cytotoxicity activity in vivo was evaluated in splenocytes obtained after 4 h of OVA loaded DC transfer (1 × 10⁷ cells, injected i.v. to OVA-immunized mice). In (d), the bars represent the mean percentage ± SE of 5 independent in vivo experiments. , Student’s t-test. (e) A representative histogram is shown. (f) 10⁷ loaded DC were transferred to OTI-mice after its treatment with Baf (0.1 μM) for 90 min at 37°C. Then, DC were treated or not with HIS (0.1 μM). Bars represent the mean cytotoxicity percentage ± SE of 5 independent experiments (, ANOVA Tukey’s test).

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