For quantification of Ova DNA, the primers used were Ova-F (5 -AAG CAG GCA GAG AGG TGG TA-3 ), Ova-R (5 -GAA TGG ATG GTC AGC CCT AA-3 ), CD8a-F (5 -GGT GCA TTC TCA CTC TGA GTT CC-3 ), and CD8a-R (5 -GCA GAC AGA GCT GAT TTC CTA TGT G-3 ). For all reaction mixtures, 10 μl of FastStart Universal SYBR green master mix (Roche) was used in a final volume of 20 μl. Ova primers were used at 500 nM and CD8a primers at 400 nM. Approximately 10 ng of DNA was added in a 5-μl volume and always set up in duplicate. Each qPCR was performed under the following conditions: 10 min hot-start denaturation at 95˚C and 40 amplification cycles (10 s at 95˚C, Frontiers in Microbiology | Microbial Immunology 30 s at 60˚C). The melting temperatures of the final double-strand DNA products were determined by gradual heating from 60 to 95˚C over 20 min. All qPCRs were performed with a StepOne-Plus real-time PCR system (Applied Biosystems) and corresponding software. Absolute amounts of Ova and CD8a amplicons, in arbitrary units, were determined using serial dilutions of pAAV-CMV-OVA plasmid or pTOPO-CD8a plasmid as a standard. The data were expressed as Ova/CD8a ratios, fixed at 1 for PBS-injected control mice.