Figure 2. Pregnancy-Primed CD8⁺ T Cells Are Cytolytic and Capable of Robust Secondary Re-expansion.

(A) Schematic showing transfer of splenocytes from Act-OVA mice on the C57BL/6 (H-2^b) background into each group of mice, including virgin control and PP21 mice after allogeneic pregnancy sired by Act-OVA (postpartum OVA⁺) or non-transgenic male mice on the BALB/c background.

(B) Absolute number (left) or normalized ratio (right) of OVA⁺ splenocytes recovered from the spleen and pooled peripheral lymph nodes 7 days following transfer into each group of mice described in (A).

(C) Number of H-2K^b:OVA_257–264 CD8⁺ T cells in the spleen and pooled peripheral lymph nodes and fold expansion from pre-transfer levels for mice described in (A).

(D) Schematic showing transfer peptide-loaded target cells, their relative persistence, and calculated percent lysis of target cells loaded with OVA_257–264 (CFSE^hi) compared with irrelevant control peptide (Zika virus NS5 227–234 peptide; CFSE^lo) 48 h following adoptive transfer into female virgin compared with PP21 mice after allogeneic pregnancy sired by Act-OVA males on the BALB/c background.

Data are from at least 3 independent experiments, each with similar results, with each point representing data from an individual mouse.

Bar, mean ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.005.