Figure 7. Cytolytic activity against FrCas^E-infected cells of 667 and of anti-FrCas^E antibodies endogenously produced in infected/treated mice.

In vivo cytolysis activities were assayed after administration of CFSE-labeled FrCas^E-infected splenocytes (SpFr) followed by administration of antibodies from various sources and cytometry analysis after 5 or 24 hours. (A) Cytolytic activity of 667. SpFr were administered i.v. and, then, 667 or PBS i.p. Values are the average ± SEM of experiments conducted with 4 mice per condition. The statistical significance was established using the Student's t test (*P = 0,0007). (B) Cytolytic activity of sera from infected/treated- and infected/non-treated mice. After administration of SpFr, three groups of 4 mice each were treated with equivalent volumes (175 µl) of pools of sera from 2 non-infected/non-treated-, 2 infected/non-treated- and 2 infected/treated mice. Values are the average ± SEM of experiments conducted with 4 mice per condition. Statistical significance of sera from infected/treated group versus the other two groups was determined by a non-parametric one-way ANOVA test with Dunn's multiple comparison post-test. *P<0,05. (C) Cytolytic activity of 667 in mice treated with either anti-NK antibodies or cobra venom factor. SpFr mixed with 667, or PBS for control, were administered i.v. to mice treated or not with either anti-NK antibodies or the cobra venom factor as described in the Methods section. The values are the average ± SEM of experiments conducted with 7 mice per condition. The statistical significance of the data obtained with sera from the infected/treated group versus those obtained in the other two groups was established using a non-parametric one-way ANOVA test with Dunn's multiple comparison post-test. (*P<0,05). (D) Cytolytic activity of sera from infected/treated in mice treated with anti-NK antibodies or cobra venom factor. SpFr mixed to 175 µl of pools of sera from 4 infected/treated were administered i.v. to mice treated or not with either anti-NK antibodies or the cobra venom factor, as described in the Methods section. The values are the average ± SEM of experiments conducted with 2 mice per condition. Statistical significance of sera from infected/treated group versus the other two groups was not assessed due to the reduced number of mice per condition.