Figure 5. Expansion of the long-term CD8⁺ T cell effector and central memory response after immunization with various forms of Rv3619c on 8 weeks post challenge with M. tb Lymphocytes isolated from spleens of animals belonging to various immunized groups were stained for expression of CD44, CD62L, on CD8⁺ T cells and analyzed by flow cytometry.

(A) The dot plot graphs in upper panel representing BCG (a), Sham (antigen free) archaeosome as control (b), Free Rv3619c Ag (c), Sham archaeosome + free Rv3619c, a physical mixture (d), Archaeosome entrapped Rv3619c Ag (e), and isotype control (f). The lower panel indicates the population of CD44 and CD62L^low/high on gated CD8⁺ T cells of corresponding upper panel. Bars indicate the total number of CD8⁺ T cells expressing CD44^highCD62L^low/high (B), The data were analyzed with the Student's t test and are shown as the means (±S.D.) of 2 independent experiments. Archaeosome encapsulated Rv3619c Vs BCG p<0.001 CD8⁺ (CD44^high, CD62L^low and CD62L^high); physical mixture of sham archaeosome and free antigen Vs BCG p<0.05 (CD8⁺CD44^high, CD8⁺CD62L^low), p = NS (CD8⁺CD62L^high); archaeosome encapsulated Rv3619c Vs free Rv3619c Ag p<0.001 CD8⁺ (CD44^high, CD62L^low and CD62L^high).