Figure 1.

Trib1 negatively regulates T cell proliferation, antiviral T cell expansion, and viral control. (A and B) Relative Trib1/TRIB1 expression measured by qPCR from (A) sorted naive murine CD4 T cells and (B) human Jurkat T cells following 4 h ± anti-CD3/CD28 stimulation. CT (cycle threshold) values normalized to 18s ribosomal RNA. (C) Quantification of microarray data from clone 13 infected mice. Expression at day 6 and day 30 p.i. in tetramer⁺ CD4 (gp66) or CD8 (gp33) T cells is displayed as fold change relative to naive (GSE41870). (D) Relative TRIB1 expression in CD4 T cells from uninfected or HIV-infected human patient samples (GSE6740). “Acute phase” denotes the clinical stage of HIV infection and not an acute infection. (E and F) Relative Trib1 expression measured by qPCR from MACs-purified CD4 T cells (E) or purified CD8 T cells from control and Trib1 cKO mice (F). CT values normalized to 18s ribosomal RNA. (G and H) CFSE dilution measured by flow cytometry from FACS-sorted naive CD4⁺CD25⁻ T cells (G) or naive CD8 T cells cultured with anti-CD3 and congenic irradiated APCs (CD45.1 spleen) for 3 d (H; gated on CD45.2⁺). (I and J) Representative flow plots (I) and summary of frequency (left) and absolute number (right) of splenic LCMV-specific CD8 (gp33⁺) T cells at day 12 p.i. (J; clone 13; gated on CD8⁺). (K) Viral titers 30 d p.i. in sera from mice infected with clone 13 LCMV. Data in E and F are representative of more than five mice per genotype. Data in G and H are representative of more than three independent experiments. Data in I and J are representative of two independent experiments each with 7–10 mice per genotype. Data in K are representative of three independent experiments each with 7–10 mice per genotype. Error bars are ± SD (A–J) or ± SEM (K). **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 by unpaired Student’s t test (A–J) or by unpaired Student’s t test with Welch’s correction (K). Control: CD4-cre⁺ Trib1^+/+; Trib1 cKO: CD4-cre⁺ Trib1^F/F. Unstim, unstimulated; max, maximum.