Journal: Frontiers in Immunology

Article Title: Early sex-related transcriptional differences in CD8 + T cells responding to chronic viral infection reveal a sex bias in exhaustion

doi: 10.3389/fimmu.2026.1783098

Figure Lengend Snippet: Sex-related CD8 + T cell responses to LCMV-Armstrong and LCMV-clone 13 infection. (a) Experimental approach (Image created with biorender.com ). Flow cytometry staining of CD62L hi CD44 lo naïve T cells (gated on CD45.1 + CD8 + T cells) is shown. F, female; M, male; Arm, LCMV-Armstrong virus; Cl13, LCMV-clone 13 virus; FACS, fluorescence activated cell sorting; scRNA-seq, single-cell RNA-sequencing. (b) Absolute cell numbers of transferred CD45.1 + CD8 + T cells that are female (F, circles) or male (M, squares), analyzed in the spleen of LCMV-Armstrong (top) or LCMV-clone 13 (bottom) infected mice at 7 dpi. Summary of three independent experiments for LCMV-Armstrong ( n = 11 mice) and four independent experiments for LCMV-clone 13 ( n = 12 female mice, n = 14 male mice). Independent experiments are represented by different shades of orange (female) and blue (male). * p<0.05, significant, ns, not significant, determined using an unpaired two-tailed Student’s t -test. Arm, LCMV-Armstrong virus; Cl13, LCMV-clone 13 virus. (c) Absolute cell numbers of transferred CD45.1 + CD8 + T cells that are female (F, circles) or male (M, squares) in the blood at 7 dpi with LCMV-Armstrong (top) and LCMV-clone 13 (bottom) viruses. Independent experiments are represented by different shades of orange (female) and blue (male). Summary of three LCMV-Armstrong and four LCMV-clone 13 independent experiments with at least three mice per group. *** p<0.001, ns, not significant, determined using an unpaired two-tailed Student’s t -test. Arm, LCMV-Armstrong virus; Cl13, LCMV-clone 13 virus; dpi, days post-infection. (d) MSD, Meso Scale discovery analyses of pro-inflammatory cytokines in the sera of LCMV-Armstrong (top, closed circles, closed squares) or LCMV-clone 13 (bottom, open circles, open squares) infected F, female (circles) or M, male (squares) mice at 7 dpi. Summary of two independent experiments with five to twelve mice per group. Box and whiskers plots show minimum and maximum values and line at the median. Each symbol represents an individual mouse. Error bars indicate standard error of the mean (SEM). ** p<0.01, * p<0.05, ns, not significant, statistical significance of differences was analyzed between female and male samples per infection type, determined using unpaired two-tailed Student’s t -test.

Article Snippet: Congenic marked CD45.1 C57BL/6 mice and CD45.2 P14 C57BL/6 mice, which have T cell receptors specific for the LCMV glycoprotein 33–41 peptide residues (GP 33-41 ) in the context of H-2D b , were purchased from The Jackson Laboratory.

Techniques: Infection, Flow Cytometry, Staining, Virus, Fluorescence, FACS, Single Cell, RNA Sequencing, Two Tailed Test

Journal: Frontiers in Immunology

Article Title: Early sex-related transcriptional differences in CD8 + T cells responding to chronic viral infection reveal a sex bias in exhaustion

doi: 10.3389/fimmu.2026.1783098

Figure Lengend Snippet: Early transcriptional sex-related differences in CD8 + T cells responding to LCMV-clone 13 infection. (a) UMAP visualization of single CD8 + T cells obtained as in Figure 1 among naïve female (light blue) 15,462 cells and male (dark blue) 15,114 cells, female day 4 LCMV-Armstrong (light green) 4, 343 cells, male day 4 LCMV-Armstrong (dark green) 7, 398 cells, female day 4 LCMV-clone 13 (light orange) 33, 892 cells, male day 4 LCMV-clone 13 (orange) 18, 531 cells, female day 7 LCMV-Armstrong (pink) 14,933 cells, male day 7 LCMV-Armstrong (red) 15,178 cells, female day 7 LCMV-clone 13 (lavender) 7081 cells, and male day 7 LCMV-clone 13 (purple) 11,796 cells. F, female; M, male; d, day; Arm, LCMV-Armstrong virus; Cl13, LCMV-clone 13 virus. Summary of two independent scRNA-seq experiments with 4 mice per group. (b) Heatmap visualization of the top-10 upregulated differentially expressed genes between each population of single CD8 + T cells including female day 4 LCMV-clone 13, male day 4 LCMV-clone 13, female day 4 LCMV-Armstrong, and male day 4 LCMV-Armstrong (log FC > 0.5; FDR < 0.01). Three genes were differentially expressed in both female and male day 4 Armstrong, these are noted by overlapping brackets at the top of the heatmap. (c) MFI, Mean fluorescence intensity of IL-2Rα protein expression on female and male CD45.1 + CD8 + T cells at 4 days post-infection with LCMV-clone 13, analyzed by flow cytometry. Error bars indicate standard error of the mean (SEM). Summary of two independent experiments, n = 8 female mice, n = 7 male mice. *p<0.05, determined using an unpaired two-tailed Student’s t -test. (d) Absolute cell numbers of TNFα + IFN-γ + expressing female (open circles) and male (open squares) CD45.1 + CD8 + T cells at 4 days post-infection with LCMV-clone 13, measured by flow cytometry. One of two independent experiments with five mice per group. * p<0.01, determined using an unpaired two-tailed Student’s t -test. (e) LCMV-clone 13 virus titer in the sera of female (open circles) and male (open squares) mice at 4 days post infection. Summary of two independent experiments with 11 mice per group. pfu, plaque forming units. ns, not significant, determined using an unpaired two-tailed Student’s t -test. (f) Dot plot of selected T cell exhaustion-associated genes where each dot represents the expression of a gene in the different CD8 + T cell population indicated on the horizontal. The size of the dot indicates the proportion of cells in which the transcript was detected and the color indicates the z-score expression of each gene in a population. (g) Absolute cell numbers of female (open circles) and male (open squares) CD45.1 + CD8 + T cells expressing CD62L (summary of two independent experiments, n = 10 female mice, n = 9 male mice), TCF-1 (summary of two independent experiments, n = 7 female mice, n = 8 male mice), PD-1 (summary of two independent experiments with eight mice per group), TIM-3 (summary of two independent experiments with eight mice per group), and LAG-3 (one of two independent experiments with 4 mice per group) measured by flow cytometry, at 4 days post infection with LCMV-clone 13 virus. Box and whiskers plots show minimum and maximum values and line at the median. *p<0.0001, * p<0.05, ns, not significant, determined using an unpaired two-tailed Student’s t -test.

Article Snippet: Congenic marked CD45.1 C57BL/6 mice and CD45.2 P14 C57BL/6 mice, which have T cell receptors specific for the LCMV glycoprotein 33–41 peptide residues (GP 33-41 ) in the context of H-2D b , were purchased from The Jackson Laboratory.

Techniques: Infection, Virus, Fluorescence, Expressing, Flow Cytometry, Two Tailed Test

Journal: Frontiers in Immunology

Article Title: Early sex-related transcriptional differences in CD8 + T cells responding to chronic viral infection reveal a sex bias in exhaustion

doi: 10.3389/fimmu.2026.1783098

Figure Lengend Snippet: Sex bias in exhausted CD8 + T cell differentiation in vivo . (a) MFI, Mean fluorescence intensity of PD-1 expressing female (orange circles) or male (blue squares) CD45.1 + CD8 + T cells in the spleen at 28 days post infection with LCMV-clone 13, measured by flow cytometry. Summary of two independent experiments with seven mice per group. Error bars indicate SEM, standard error of the mean. ns, not significant, determined using unpaired two-tailed Student’s t -test. (b) Absolute cell numbers of Tex, terminally exhausted female (orange circles) or male (blue squares) CD45.1 + CD8 + T cells in the spleen at 28 dpi with LCMV-clone 13, measured by flow cytometry. One of two independent experiments with 5 mice per group. Error bars indicate standard error of the mean (SEM). * p<0.05, determined using unpaired two-tailed Student’s t -test. (c) Frequency (%) of Ki-67 + expressing naïve or activated female (orange circles) or male (blue squares) CD45.1 + CD8 + T cells in the spleen at 28 dpi with LCMV-clone 13, measured by flow cytometry. One of two independent experiments with 5 mice per group. Error bars indicate SEM, standard error of the mean . * p<0.05, comparison between female versus male cells at each time-point (naïve, 28 days post infection), determined using an unpaired two-tailed Student’s t -test. (d) Frequency (%) of IL-2 + cells (gated on IFN-γ + TNFα + Tex cells) which are female (orange circles) or male (blue squares) Tex, terminally exhausted CD45.1 + CD8 + T cells in the spleen at 28 dpi with LCMV-clone 13, measured by flow cytometry. One of two independent experiments with 5 mice per group. Error bars indicate standard error of the mean (SEM). * p<0.05, determined using unpaired two-tailed Student’s t -test.

Article Snippet: Congenic marked CD45.1 C57BL/6 mice and CD45.2 P14 C57BL/6 mice, which have T cell receptors specific for the LCMV glycoprotein 33–41 peptide residues (GP 33-41 ) in the context of H-2D b , were purchased from The Jackson Laboratory.

Techniques: Cell Differentiation, In Vivo, Fluorescence, Expressing, Infection, Flow Cytometry, Two Tailed Test, Comparison