Figure 2. Increased antigen-specific T cell responses with enhanced functional avidity following VACV in an adoptively transferred mice model using OVA as antigen.

To exclude the effect of TCR selection, the TCR transgenic OT-1 mice was introduced, the purified monoclonal TCR OT-I CD8⁺ T cells were adoptively transferred into wild type C57BL/6 mice and immunized with OVA antigen as scheduled in (A), (B to D) VACV boost could induce stronger antigen-specific T cell responses (B) with higher functional avidity (C). The EC₅₀ of peptide concentration required for IFN-γ production was shown in (D). (E) To verify the feasibility of this adoptive transfer model, we calculated the percentage of CD45.1⁺ in IFN-γ⁺ cells after OVA peptide stimulation, data showed that the proportion was almost 90% whereas only 6% by PMA/ionomycin non-specific stimulation, demonstrating that the OVA-specific immune response was dominantly triggered by the exogenous TCR transgenic CD8⁺ CD45.1⁺ T cells instead of the endogenous polyclonal population.