Volume 13, Issue 5, Pages 546-557 (May 2013) Memory CD8+ T Cells Can Outsource IFN-γ Production but Not Cytolytic Killing for Antiviral Protection  Sanda Remakus, Daniel Rubio, Avital Lev, Xueying Ma, Min Fang, Ren-Huan Xu, Luis J. Sigal  Cell Host & Microbe  Volume 13, Issue 5, Pages 546-557 (May 2013) DOI: 10.1016/j.chom.2013.04.004 Copyright © 2013 Elsevier Inc. Terms and Conditions

Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 1 M-WT but Not M-IFN-γ−/− CD8+ T Cells Efficiently Protect IFN-γ−/− Mice from Mousepox (A) IFN-γ−/− mice received 5 × 106 N-WT, M-WT, or M-IFN-γ−/− CD8+ T cells and were infected with ECTV. Survival was monitored. The experiment is representative of three, where n = 5 for every group except for M-IFN-γ−/−, where n = 6. (B) The mice in (A) were weighed daily. (C) IFN-γ−/− mice that received 5 × 106 N-WT, M-WT, or M-IFN-γ−/− CD8+ T cells were infected with ECTV. Seven days postinfection, mice were killed and virus titers were determined in liver. Data correspond to five mice per group ± SEM and are representative of two independent experiments. (D) As in (C), but the virus titers were determined in spleen. See also Figure S1 for liver pathology. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 2 M-WT and M-IFN-γ−/− CD8+ T Cells Respond Strongly in the Liver and Spleen of IFN-γ−/− Mice IFN-γ−/− mice received 5 × 106 N-WT, M-WT, or M-IFN-γ−/− CD8+ T cells. One day later, the mice were infected with ECTV, and at 7 dpi the mononuclear cells infiltrating the livers (A–F) and splenocytes (G–L) were incubated for 5 hr with TSYKFESV or without peptide, and the indicated parameters were determined. Data correspond to an experiment with five mice per group ± SEM, with exception of N-WT, which had two mice per group because three mice died at 7 dpi. Data are representative of two experiments. Data are represented as mean ± SEM. See also Figure S2 for representative flow cytometry plots. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 3 Memory CD8+ T Cells Deficient in IFN-γ but Not in Prf Protect Susceptible Mice from Lethal Mousepox CD8+ cells were magnetically purified from pooled LNs and spleens from donor naive or VACV-immune B6, IFN-γ−/−, or Prf−/− mice. CD8+-purified CD8+ T cells (106, 2.5 × 106 or 5 × 106) from each type of donor cell were transferred intravenously into groups of five B6.D2-D6 mice. One day later, the mice were infected with ECTV and survival was monitored. (A) The frequency of CD8+ T cells specific for the immunodominant determinant TSYKFESV was determined by staining with Kb-TSYKFESV dimers. (B) Kaplan-Meier survival curve for mice transferred with ∼65,000 Kb-TSYKFESV+ cells as determined from the results in (A). (C) Kaplan-Meier survival curve for mice transferred with ∼130,000 Kb-TSYKFESV+ cells as determined from the results in (A). All mice transferred with 106 M-WT or M-Prf−/− (∼25,000 Kb-TSYKFESV+ cells) succumbed to the infection, all the mice transferred with 5 × 106 M-IFN-γ−/− (∼270,000 Kb-TSYKFESV+ cells) survived and are not displayed graphically. (D and E) Virus titers at 7 dpi in livers (D) and spleens (E) from B6.D2-D6-Thy1.1+ mice that received 5 × 106 N-WT CD8+ T cells or enough M-WT, M-IFN-γ−/−, or M-Prf−/− CD8+ T cells to contain ∼75,000 Kb-TSYKFESV+ cells. Data are represented as a mean ± SEM and are representative of two independent experiments. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 4 Endogenous Prf but Not IFN-γ in Memory CD8+ T Cells Is Required for the Early Control of ECTV LH Spread (A and B) Virus titers at 7 dpi in livers (A) and spleens (B) from B6.D2-D6 mice that received 5 × 106 N-WT CD8+ T cells, or enough M-WT, M-IFN-γ−/−, or M-Prf−/− CD8+ T cells to contain ∼75,000 Kb-TSYKFESV+ cells. Data are representative of three independent experiments. (C–J) N-WT, M-WT, M-IFN-γ−/−, or M-Prf−/− CD8+ T cells were labeled with CFSE to identify divided donor cells. Five million N-WT CD8+ T cells or a number of M-WT, M-IFN-γ−/−, or M-Prf−/− CD8+ T cells that contained ∼75,000 Kb-TSYKFESV+ cells were transferred into B6.D2-D6-Thy1.1+ mice. One day later, the mice were infected with ECTV, and at 4 dpi D-LN cells were counted and analyzed by flow cytometry. The indicated parameters were analyzed. Data are represented as a mean ± SEM and are representative of two similar experiments. Representative flow cytometry plots are shown in (E). See also Figure S3 for Cidofovir-treated mice and confocal microscopy. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 5 Endogenous Prf but Not IFN-γ in Memory CD8+ T Cells Is Required for the Late Control of ECTV in the Liver and Spleen B6.D2-D6-Thy1.1+ mice received 5 × 106 N-WT CD8+ T cells or enough M-WT, M-IFN-γ−/−, or M-Prf−/− CD8+ T cells to contain ∼75,000 Kb-TSYKFESV+ cells. One day later, the mice were infected with ECTV, and at 7 dpi liver-infiltrating mononuclear cells (A–I) and splenocytes (J–R) were incubated for 5 hr with TSYKFESV or without peptide, and the indicated parameters were determined. Data correspond to five mice per group, with exception of uninfected mice, which had four mice per group, and N-WT, which had three mice per group, because two mice died at 7 dpi. Data are represented as a mean ± SEM and are representative of two experiments with B6.D2-D6 Thy1.1+ recipients (shown) and a third experiment using B6.D2-D6 mice as recipients. See also Figure S4 for representative flow cytometry plots and for higher ECTV doses and VACV and LCMV infection. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions

Figure 6 N-WT T cells can complement M-IFN-γ−/− CD8+ T cells to protect IFN-γ−/− mice from mousepox. IFN-γ−/− mice were transferred with 2.5 × 106 M-IFN-γ−/− CD8+ T cells and/or with 5 × 107 leukocytes (pooled splenocytes, LN cells, and liver mononuclear cells) from naive B6 mice that had been depleted or not of CD4+, CD8+, CD4+, and CD8+ T cells or NKCs as indicated. One day after transfer, the mice were challenged with ECTV in the footpad. Survival (A) and weight loss (B) are shown. Data correspond to the mean of five mice per group ± SEM and are representative of two independent experiments. See also Figure S5. Cell Host & Microbe 2013 13, 546-557DOI: (10.1016/j.chom.2013.04.004) Copyright © 2013 Elsevier Inc. Terms and Conditions