CD4
+ T cells are spontaneously activated in naive
TAM tko mice. (
A) Total lymphocytes from WT or tko spleens and lymph nodes were double-labeled with anti-CD4 and CD44 antibodies. The CD4
+ cells (as shown in
Supplementary Figure S1B) were gated for further analysis of the CD44
+ population. Histograms show the distributions and percentiles of the CD44
high T cells from the CD4
+-gated naive WT (
solid) or tko (
open) lymphocytes. The CD4 gate and no anti-CD44 controls are shown in Supplementary Figure S1B. (
B) Dot plots show increased CD4
+CD69
+ double-positive cells in tko spleens (
right, from WT 2.1% to tko 4.6%). (
C,
D) Dot plots show an increased CD4
+CD25
+ T cell population in the lymph nodes (
C) and spleen (
D) of tko mice, with the gate set on CD4
+ T cells. The PE rat IgG2b k-isotype serves as a negative control for the PE-CD25 antibody, as shown in
Supplementary Figures S1E–S1H. (
A–
D) Data are representative of those obtained from six mice in each genotype in three independent assays. (
E) Young naive tko mice exhibited decreased naive and increased central memory T cells (Tcm). The pooled spleens and lymph nodes (inguinal, iliac, axillary, and submandibular) of three naive WT or tko female mice at ages of 4 to 5 weeks were prepared for single-cell suspension and stained with CD4-FITC, CD25-APC, CD62L-PerCp5.5, and CD45RA-PE antibodies. Viable lymphocytes were gated on FSC versus SSC dot plots (
Ea) and were separated for the CD4
+CD25
− T cell population on CD4-FITC versus CD25-APC scattering dot plots (
Eb). A second gate was then set on the CD4
+CD25
− T cell population for further analysis of CD62L and CD45RA subsets by CD62L-PerCy5.5 versus CD45RA-PE scattering dot plots (
Ec,
Ed). CD4
+CD25
−CD62L
+CD45RA
+ and CD4
+CD25
−CD62L
+CD45RA
− are naive (
upper right) and central memory (Tcm,
lower right) T cell subsets, respectively. The percentile numbers in the dot-plots are the average of two sets of independent assays (total, six mice) and are summarized in (
Ee).