Polyclonal CD4⁺ T cells support maintenance of AdVova transgene product-specific CTLs.

<p>(<b>a</b>) Ten days following immunization, total CD8⁺ CTLs containing AdVova-specific effector CTLs were purified from B6.1 mice (CD45.1⁺ background) and adoptively transferred to naïve congenic WT and MHCII^−/− mice (CD45.2⁺ background; ∼15×10⁶/mouse). The OVA-specific tetramer⁺ CTLs were tracked after staining peripheral blood samples with tetramer reagent and congenic marker up to 30 days post-adoptive transfer. The values represent mean %±SD of OVA-specific tetramer⁺ CTLs in total CD45.1⁺ adoptively transferred T cell population at the indicated intervals (right panel) and are representative of two independent experiments with five to six mice per group. **<i>P</i><0.01, versus MHCII^−/− mice. (<b>b</b>) Forty-five days after adoptive transfer, the above mice groups were challenged with BL6-10_OVA. Twenty-four days after the challenge, both groups were assessed for tumor protection. Images represent distorted pathology of lungs, showing relative surface tumor burden. (<b>c</b>) Ninety days following the immunization, total CD8⁺ T cells containing AdVova-specific memory CTLs were purified from WT mice and adoptively transferred into naïve WT and MHCII^−/− mice (∼15×10⁶/mouse). The OVA-specific tetramer⁺ CTLs were tracked in peripheral blood samples by tetramer staining. The values represent mean %±SD of OVA-specific tetramer⁺ CTLs in total CD8⁺ T cell population at the indicated intervals (right panel) and are representative of two independent experiments with four to six mice per group. **<i>P</i><0.01, versus MHCII^−/− mice. (<b>d</b>) Thirty days after the adoptive transfer, the above mice groups (<b>c</b>) were challenged with BL6-10_OVA and the relative surface tumor burden was assessed 24 days after the challenge as detailed above.