A: CD107a expressing CD8+ T and CD3-CD8+NKG2A+ NK cells in PBMCs following incubation overnight with rIL-15 from the vaccinees collected at pre-vaccination (pre-vac), 35 weeks post-infection with vaccine (wpv), 10 and 45 weeks post-challenge infection (wpc).
B: Statistical analysis of the data presented in A. NS (not significant) p >0.05, *p < 0.05, ** p <0.01.
C: Comparison of the frequencies of CD107a-expressing CD8+ T and CD3-CD8+NKG2A+ NK cells in response to rIL-15 in vitro among the different group of animals. While the frequencies of the two cell lineages varied, the predominant cells were NK cells in Mm0301 and Mm0516, the predominant responding cells were CD8+ T cells in Mm0303, Mm0512 and Mm0517. In addition, while both CD8+ T and NK cells were stimulated, the frequencies were lower among controllers (Mm0511 and Mm0515). The response to rIL-15 by PBMCs from the non-controllers (Mm0304, Mm0409 and Mm0518) decreased to or remained at very low levels following challenge infection. In contrast, PBMCs from animal Mm0513 showed an increase in the frequencies of rIL-15 responding cells.