Fig. 3

Cytomegalovirus (CMV) replication is required for optimal induction of CD8⁺ T-cell memory formation in the lungs following mucosal infection. C57BL/6 mice were intranasally infected with 2 × 105 PFU of WT-MCMV or ΔgL‑MCMV. Leukocytes were isolated from perfused lungs 9 weeks post infection, and T-cell responses were quantified using flow cytometry. Representative concatenated FACS plots of tetramer-bound CD8⁺ T cells reactive to M38 or IE3 (A). Numbers of tetramer-binding effector memory T cells (TEM: CD8⁺ CD3⁺ CD44⁺ CD62L⁻), central memory T cells (TCM: CD8⁺ CD3⁺ CD44⁺ CD62L⁺) and tissue resident memory T cells (CD8⁺, CD3⁺ CD69⁺, CD103⁺) reactive to M38 (B) or IE3 (C). Data shown as mean +/− SEM (n = 6 mice per group). *p ≤ 0.05, **p ≤ 0.01, Mann‒Whitney unpaired t test. D Concatenated flow cytometry plots of IFNγ and TNF-α expression by M38- and IE3-specific CD8⁺ T cells in the lungs of mice infected with WT-MCMV or ΔgL‑MCMV. Total numbers of polyfunctional and monofunctional T cells in the lungs gated on live CD8⁺ T cells reactive to M38 (E) or IE3 (F). *p ≤ 0.05, **p ≤ 0.01, ordinary one-way ANOVA for multiple comparisons. All data represent 2–3 independent experiments