A CHAPTER INVESTIGATIONS ON EV71 VIRULENT DETERMINANTS 178 CHAPTER INVESTIGATIONS ON EV71 VIRULENT DETERMINANTS B Figure 6.5 Adaptive immune response in EV71-infected AG129 mice. (A) Two-week-old mice were infected at 107 PFU/mouse or inoculated with PBS. At day and 12 PI, mice (n=5) were euthanized and their spleens were harvested. Total splenocytes were counted or stained with monoclonal antibodies specific for CD4, CD9, CD19, CD69, and CD138 markers and analysed by flow cytometry. Data was expressed as log cell number per spleen, or percentage composition per spleen. The dotted line indicates the highest amount or percentage of cells observed for the two fatal strains. (B) Specific anti-EV71 IgM and IgG titers in sera of infected mice were determined via ELISA for three time points. Two-week-old mice were infected at 107 PFU/mouse or inoculated with PBS. At day 4, and 12 PI, mice (n=5) were bled and IgM and IgG levels were quantified by ELISA. Dotted line indicates the highest fold change observed for the two fatal strains. Results were only obtained for S10-infected mice at day and PI due to animals’ death. Data were expressed as mean ± SEM. *, P < 0.05, **, P < 0.01, ***, P < 0.001. 179 . CHAPTER 6 INVESTIGATIONS ON EV71 VIRULENT DETERMINANTS 178 A CHAPTER 6 INVESTIGATIONS ON EV71 VIRULENT DETERMINANTS 179 Figure 6.5 Adaptive immune response in EV71-infected. percentage composition per spleen. The dotted line indicates the highest amount or percentage of cells observed for the two fatal strains. (B) Specific anti-EV71 IgM and IgG titers in sera of infected. (n=5) were euthanized and their spleens were harvested. Total splenocytes were counted or stained with monoclonal antibodies specific for CD4, CD9, CD19, CD69, and CD 138 markers and analysed by