Fig. 6

Immune responses in rPvRAMA-immunized mice. a Sera from rPvRAMA-immunized mice were diluted in a two-fold series from 1:10,000 to 1:5,120,000. Levels of total IgG against rPvRAMA protein were measured by an enzyme-linked immunosorbent assay (ELISA) and are presented in the form of OD values. b Levels of total IgG against rPvRAMA protein in rPvRAMA-immunized and PBS-immunized mice measured by ELISA at the 7-day time-point after each immunization. c Levels of IgG subclasses in rPvRAMA-immunized mice. Means were calculated for the IgG1 (black), IgG2a (light gray), IgG2b (white) and IgG3 (dark gray) isotypes per group of 3 mice. d Levels of cytophilic and non-cytophilic IgG isotypes in the serum of rPvRAMA-immuned mice. Means were calculated for cytophilic (black) and non-cytophilic (white) IgG isotypes per group of 3 mice. e, f After stimulating the splenocytes of rPvRAMA-immunized and PBS-immunized mice by rPvRAMA protein in vitro, the percentage of CD4⁺ and CD8⁺ T cells to total CD3⁺ T cells were measured by flow cytometry. The data are shown as the mean ± SD. P values were calculated using Student's t-test, with the asterisks indicating a significant difference at *P < 0.05, **P < 0.01 and ***P < 0.0001. IgG, Immunoglobulin G; OD, optical density; PBS, phosphate-buffered saline