Figure 1. CD4⁺ T cells are not primed for immunity in mice injected AC.

A. Wildtype B6 mice were injected s.c. or AC with 2.5 × 10⁴ pfu HSV-1. Some groups of mice were depleted of CD8⁺ cells by 3 daily 100 µg doses of using anti-CD8 (mAb 2.43) prior to AC injection. After 7 d, splenic CD4⁺ T cells were purified and transferred to naïve B6 recipient mice that were immediately challenged with 10⁶ pfu UV-inactivated HSV-1 in 33 µl PBS in the right and 33 µl PBS in the left footpad. Measurements (µm ± S.E.) were taken 24 h later, and represent the difference between the right (Ag challenge) and left footpad (PBS challenge). The background value represents the difference between challenged and unchallenged sites in mice that received CD4⁺ T cells from naïve mice. * p < 0.05 vs. s.c. B. Wildtype B6 mice received 10⁶ CFSE-labeled OT-II T cells 24 h before AC injection of 2.5 × 10⁴ pfu HSV-1. As a positive control, some mice were injected with CFA/OVA s.c. After 5 d, splenocytes from the recipient mice were isolated, and cell proliferation, as measured by CFSE dilution, was determined by flow cytometry. The percentage of undivided cells is indicated for each group. C. Quantitative RT-PCR analysis shows increased TRAIL mRNA expression in CD8⁺ T cells from AC-injected mice. Groups of wildtype B6 mice (4/group) were immunized with 0.1 ml of 10 mM TNBS s.c., but one group received 5 × 10⁵ TNP-coupled splenocytes AC 48 h before s.c. immunization. Spenic CD8⁺ T cells were MACS-isolated 24 h after s.c. immunization, and TRAIL mRNA expression was measured by qRT-PCR. The relative increase was determined by comparing RNA levels to splenic CD8⁺ T cells obtained from naïve mice.