Cross-presentation of FluM1 in humanized mice. Experimental protocols: (A) NOD/SCID β₂m^−/− mice were reconstituted with 20 × 10⁶ sorted T cells and with 10 × 10⁶ sorted B cells (purity > 99%) and vaccinated with TIV intraperitoneally/intravenously. (B) NOD/SCID β₂m^−/− mice were transplanted with CD34⁺ HPCs and reconstituted with 20 × 10⁶ autologous sorted total T cells (purity > 99%) before vaccination. TIV was given intraperitoneally/intravenously. (C,D) The frequency of FluM1-specific CD8⁺ T cells in NOD/SCID β2m^−/− mice (C) or (D) in humanized mice at day 12 after vaccination. (E) The frequency of FluM1-specific CD8⁺ T cells (mean ± SEM, n = 3 for each cohort at each time point) at different time points after vaccination. (F) The numbers of total human CD8⁺ T cells (mean ± SEM, n = 3 for each cohort at each time point) measured in the same volume of blood at different time points after vaccination.