Fig 5.

Robust epitope P1⁵¹⁹-specific T cell responses following MNV infection. Mice were infected p.o. with 1.5 × 10⁶ PFU of MNV-CW3 or MNV-CR6. (A) Viral load in the terminal ileum (TI) was assessed on day 8 p.i. with MNV-CW3 or MNV-CR6. Dotted line indicates limit of detection. (B) Epitope-specific CD8 T cells in the indicated tissues were detected by tetramer staining on day 8 p.i. The data are representative of 8 mice per group. (C) Fractions of epitope-specific CD8 T cells in the IEL and LPL. The average absolute numbers of Tet⁺ IEL on day 8 were 1 × 10⁵ for MNV-CW3 and 1.5 × 10⁴ for MNV-CR6. (D) Total numbers of Tet⁺ CD8 T cells in spleen and MLN at day 8 p.i. In panels A, C, and D, horizontal lines show the means. (E) The epitope-specific CD8 T cell response in the LP was tracked for 29 days p.i. (F) Graph shows longitudinal summary data for the percentages of CD8 T cells staining with the respective MNV tetramer for MNV-CW3 versus MNV-CR6 infection. Note that MNV-CW3 and MNV-CR6 differ by a single amino acid in epitope P1⁵¹⁹, and therefore, tetramers matching the appropriate strain were used in these experiments. In the experiment whose results are shown in panel A, naive cells were from the spleen; in the experiment whose results are shown in panel E, naive cells were from the LP. Naive cells from MLN and IEL showed similar backgrounds of tetramer staining (data not shown). *, differences between groups by the unpaired t test were statistically significant (P < 0.05).