Fig 2: Inhibition of EIF4G2 hinders the effect of LINC00641 on depression-like behaviors of CUMS mice. A-D The expression level of EIF4G2 in the hippocampal tissues of mice in each group; E Results of sucrose preference experiments in mice treated with AAV-LINC00641 and AAV-shEF4G2; F-G Results of TST and FST in mice treated with AAV-LINC00641 and AAV-shEF4G2; H-J 5-HT, NE, and DA in brain tissues of mice treated with AAV-LINC00641 and AAV-shEF4G2; K Representative images of HE staining of hippocampal neurons in mice treated with AAV-LINC00641 and AAV-shEF4G2; L-M Apoptosis of hippocampal neurons in mice treated with AAV-LINC00641 and AAV-shEF4G2; n = 10 animals per group. The comparisons were made by Student’s t-test; ** P < 0.01, ***P < 0.001

Fig 3: eIF4G2 facilitates CD8+ T lineage commitment after positive selection(A) Flow cytometry gating strategy for WT and Eif4g2 cKO thymocytes based on CD3 and CD69 expression and representative plots for WT and Eif4g2 cKO mice are shown.(B and C) Quantification of the thymocyte subpopulations defined in (A). Bar graphs show the frequencies of each population within total thymocytes (n = 6, ns p > 0.05, ∗∗∗p < 0.001, ∗p < 0.05).(D) Gating strategy to analyze CD4 and CD8 expression within CD3highCD69+ population.(E) Ratio of CD4+CD8−, CD4+CD8lo, or CD4−CD8+ cells in CD3highCD69+ population (n = 6, ns p > 0.5, ∗∗∗p < 0.001).(F) Ratio of CD4+CD8− or CD4−CD8+ cell in CD3highCD69- population (n = 6, ∗p < 0.5, ∗∗∗p < 0.001); Data are representative of at least two independent experiments. Bar graphs show mean ± SEM and unpaired Students’t test was used to perform the statistical analysis.

Fig 4: Conditional deletion of Eif4g2 specifically impairs SP thymocyte development(A and B) Validation of eIF4G2 protein deletion by western blot. (A) Total thymocytes.(B) Lysates from sorted thymocyte subsets: double-negative (DN), double-positive (DP), and single-positive (SP) cells.(C) Representative images of thymus from WT and Eif4g2 cKO mice.(D) Total thymocytes numbers from WT and Eif4g2 cKO mice (n = 3 per group, ns p > 0.05).(E) Flow cytometric analysis of thymocyte populations.(F–H) Relative frequencies and absolute numbers of (F) CD4 SP, (G) CD8 SP, and (H) TCRβ+CD8+ subsets (n = 3–6 mice per group, presented as mean ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.001).(I–M) Frequencies of (I) DN, (J) DP cells within total thymocytes, and (K) Foxp3+ cell within CD4+ T cells (n = 5–6 mice per group, presented as mean ± SEM, ns p > 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001); (L and M) Analysis of innate-like T cells in the thymus.(L) Frequencies of NK1.1+ T cells and (M) γδ T cells (n = 5 mice per group, presented as mean ± SEM. ns p > 0.05, ∗∗∗p < 0.001).(N–P) Evaluation of peripheral T cells in situ.(N) Absolute numbers of splenic T cells, (O) frequencies of CD44+CD62L− cells and (P) IFNγ+ cells (n = 3 mice per group, presented as mean ± SEM. ∗p < 0.05, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001).(Q and R) Cytokine production upon stimulation. Frequencies of (Q) IFNγ+ and (R) TNFα+ cells among peripheral naive T cells following ex vivo anti-CD3/CD28 stimulation (n = 3 mice per group, bar graphs show mean ± SEM. ∗p < 0.05, ∗∗p < 0.01). Data are representative of at least two independent experiments unpaired Students’t test was used to perform the statistical analysis. See also Figure S2.

Fig 5: eIF4G2 specifically sustains surface expression of the IL-7 receptor(A–C) Expression of IL-7Rα (CD127). (A) Representative histogram and (B) quantification of CD127 median fluorescence intensity (MFI) on CD4+CD8lo transitional cells (n = 3, ∗∗p < 0.01).(C) MFI of CD127 on DP, CD4 SP, and CD8 SP thymocytes (n = 3, ns p > 0.05, ∗∗∗∗p < 0.0001).(D–F) Expression of the common γc (CD132).(D) Representative histogram and (E) quantification of CD132 MFI on CD4+CD8lo transitional cells (n = 4, ∗p < 0.05).ppp(F) MFI of CD132 on DP, CD4 SP, and CD8 SP thymocytes (n = 3, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001).(G and H) Expression of IL-4Rα (CD124) expression detection on CD4+CD8lo transitional cells.(G) Representative histogram and (H) quantification of CD124 MFI on CD4+CD8lo transitional cells (n = 3, ns p > 0.05).(I and J) Expression of GP130 on CD4+CD8lo transitional cells.(I) Representative histogram and (J) quantification of GP130 MFI on CD4+CD8lo transitional cells (n = 3, ∗∗p < 0.01).(K) Quantification of CD124 MFI on DP, CD4 SP and CD8 SP (n = 3, ns p > 0.05).(L–N) Expression of IL-2Rα (CD25).(L) Representative histogram and (M) quantification of CD25 MFI on CD4+CD8lo transitional cells (n = 3, ns p > 0.05).(N) MFI of CD25 on DP, CD4 SP, and CD8 SP subsets (n = 3, ns p > 0.05). Data are representative of at least two independent experiments. Bar graphs show mean ± SEM and unpaired Students’t test was used to perform the statistical analysis.