Figure 3

Increased CTL response against HLA-A11-restricted epitopes in the HLA-A11/hTAP-LMP mice.

(A) Experimental outline for DNA vaccination and subsequent assessment of HLA-A11-restricted CTL responses. (B) HLA-A11/hTAP-LMP and control HLA-A11 mice were vaccinated twice with 100 μg of pcDNA3.1(+)/HBcAg and then splenocytes were separated and analyzed for CTLs against HLA-A11-restricted epitopes using IFN-γ Elispot assays. Two published HLA-A11 restricted epitopes, HBc_141-151 (STLPETTVVRR, 14) and HBc_88-96 (YVNTNMGLK, 67) and 19 peptides with K/R C-termini that potentially elicit HLA-A11-restricted CTL responses were synthesized and used in the Elispot assays. Initially, the 19 peptides were divided into three pools for ex vivo stimulation (Table 1). Single or overlapping peptides from pool 2 were further used to screen for HLA-A11-restricted epitopes. (C) Splenocytes as in (B) were used to test for HBc_141–151-specific CD8⁺ T cells by ICS. The left plot shows the representative FACS diagram, indicating the percentage of CD8⁺ IFN-γ⁺ cells in the total CD8⁺ T cells; the right chart depicts the cumulative data. (D) A minigene encoding a known HLA-A11-restricted peptide, NP_91–100 (RTGGPIYRR), was used to vaccinate HLA-A11 and HLA-A11/hTAP-LMP mice. The NP_91–100-specific CTL response was tested by IFN-γ ICS (left) and IFN-γ Elispot assays (right). The results are representative of at least three independent experiments with n ≥ 3. Data represent the mean ± SD. *p < 0.05 and **p < 0.01, unpaired t-test.