ifn-γ eyfp reporter mice  (Jackson Laboratory)

Journal: mSphere

Article Title: Delayed Activation of T Cells at the Site of Infection Facilitates the Establishment of Trypanosoma cruzi in Both Naive and Immune Hosts

doi: 10.1128/msphere.00601-22

Figure Lengend Snippet: Parasite control at the site of entry coincides with the generation of an adaptive immune response. (a) IFN-γ-deficient (IFNgko) and C57BL/6 (B6 wt) mice were infected in the footpads with CL-tdTomato-expressing parasites, and the infection level at the site was measured by in vivo imaging until 14 days postinfection, when IFN-deficient mice had to be euthanized due to excessive pathology. (b) NK cell-depleting antibody against NK1.1 (PK136) and isotype control (IgG) were administered to C57BL/6 mice before and after the infection with tdTomato-expressing parasites in the footpads. (c and d) C57BL/6 mice were infected in the ears, and the proportions of CD8 + (c) and CD4 + (d) T cells infiltrating the site were determined by flow cytometry. Asterisks in panels c and d denote the time points at which the difference from the first sample became statistically significant ( P < 0.05). (e) Maximum intensity projection images from whole mounted ears labeled with anti-CD4 antibody at 7 and 20 days after infection with tdTomato-expressing T. cruzi . (f) IFN-γ-YFP reporter mice were infected in one ear, and the percentages of YFP + lymphocytes in the infected and contralateral ears were determined by flow cytometry. (g) Kinetics of parasite proliferation at the site of infection (paras load) and CD8 + T cell response specific to the T. cruzi peptide TSKB20 (TSKB20 resp) were tracked by in vivo imaging and MHC class I-TSKB20 tetramer complex staining of peripheral blood, respectively, in C57BL/6 mice infected in the footpads with CL-tdTomato-expressing parasites. *, P < 0.05.

Article Snippet: Mice deficient in CD8 + T cells (B6.129P2-B2mtm1Unc/J), IFN-γ reporter mice (B6.129S4-Ifngtm3.1Lky/J [IFN-γ eYFP “GREAT”]), B6.IL-12yet40 reporter mice (IL-12yet40) and IFN-γ-deficient mice (B6.129S7-Ifngtm1Ts/J) were purchased from the Jackson Laboratory (Bar Harbor, ME).

Techniques: Infection, Expressing, In Vivo Imaging, Flow Cytometry, Labeling, Staining

Journal: mSphere

Article Title: Delayed Activation of T Cells at the Site of Infection Facilitates the Establishment of Trypanosoma cruzi in Both Naive and Immune Hosts

doi: 10.1128/msphere.00601-22

Figure Lengend Snippet: Parasites at the site of entry are controlled by infiltrating lymphocytes producing IFN-γ. (a) C57BL/6 mice were infected intramuscularly in the hind legs with 2.5 × 10 5 trypomastigotes of Colombiana- T. cruzi expressing luciferase, and the parasite load at the site of infection was approximated by in vivo imaging of luciferase activity. Mice with fluorescently tagged T cells received an intramuscular injection of parasites expressing tdTomato and a mock phosphate-buffered saline (PBS) injection in the contralateral leg (contralateral). (b) Tissue samples from both legs were obtained early (day 3), near the peak of parasite load (day 10), and late (day 20) postinfection, clarified, and imaged by LSFM. The results of automated quantification of parasite-infected host cells (note that quantification of individual parasites within infected host cells is not possible at this magnification level ) and T cells in the muscle samples of infected or mock-injected muscle are indicated. (c) Lymphocyte-deficient (RAGko) and C57BL/6 (B6 wt) mice were infected in the footpads with CL-tdTomato-expressing parasites, and the infection level was measured by in vivo imaging. (d) C57BL/6 mice infected in the footpads with CL-tdTomato-expressing parasites were treated with FTY720 from day 2 to day 10 after infection, and the kinetics of parasite load at the site were measured by in vivo imaging. *, P < 0.05 (Mann-Whitney U test).

Article Snippet: Mice deficient in CD8 + T cells (B6.129P2-B2mtm1Unc/J), IFN-γ reporter mice (B6.129S4-Ifngtm3.1Lky/J [IFN-γ eYFP “GREAT”]), B6.IL-12yet40 reporter mice (IL-12yet40) and IFN-γ-deficient mice (B6.129S7-Ifngtm1Ts/J) were purchased from the Jackson Laboratory (Bar Harbor, ME).

Techniques: Infection, Expressing, Luciferase, In Vivo Imaging, Activity Assay, Injection, MANN-WHITNEY

Journal: mSphere

Article Title: Delayed Activation of T Cells at the Site of Infection Facilitates the Establishment of Trypanosoma cruzi in Both Naive and Immune Hosts

doi: 10.1128/msphere.00601-22

Figure Lengend Snippet: CD4 + T cells are the main source of IFN-γ for parasite control at the site of entry. (a and b) Sorted effector CD8 + (a) or CD4 + (b) T cells coming from IFN-γ-deficient (IFN-g ko) or C57BL/6 wild-type (wt) infected mice were transferred into IFN-γ-deficient mice the day prior to infection with CL-tdTomato-expressing parasites in the footpads, and parasite proliferation at the site was measured by in vivo imaging. (c) Local pathology in the animals of the groups receiving CD4 + T cells is expressed as swelling of the feet. (d and e) Mice deficient in CD4 + T cells (MHCII ko) (d), mice deficient in CD8 + T cells (B2m ko) (e), and C57BL/6 mice (B6 wt) were infected in the footpads with CL-tdTomato-expressing parasites, and the fluorescence at the site was measured by in vivo imaging. (f) Ear cells from the site of T. cruzi infection (9 days postinfection) of IFN-γ-YFP reporter mice were stained with antibodies against CD4 and CD8, and the mean fluorescence intensity (MFI) of YFP + cells was measured by flow cytometry. *, P < 0.05; ns, not significant. †, time point at which the animals had to be euthanized due to excessive pathology.

Article Snippet: Mice deficient in CD8 + T cells (B6.129P2-B2mtm1Unc/J), IFN-γ reporter mice (B6.129S4-Ifngtm3.1Lky/J [IFN-γ eYFP “GREAT”]), B6.IL-12yet40 reporter mice (IL-12yet40) and IFN-γ-deficient mice (B6.129S7-Ifngtm1Ts/J) were purchased from the Jackson Laboratory (Bar Harbor, ME).

Techniques: Infection, Expressing, In Vivo Imaging, Fluorescence, Staining, Flow Cytometry