Verification of Socs3^fl deletion in T cells. (A) Cells expressing lineage-specific markers were purified from Socs3^+/ΔLck bone marrow (BM), peritoneal cavity (Peri), LN, or spleen. Genomic DNA was genotyped at the Socs3 locus by PCR. The bands corresponding to the different Socs3 alleles are indicated. Gr indicates granulocytes; B, B cells; Ery, erythroid cells; Mac, macrophages; T, T cells; Thy, thymocytes. (B) SOCS3 expression in purified T cells from wt (open bars) or Socs3^ΔLck/ΔLck (filled bars) mice, either unstimulated or after IL-2 stimulation for 1 hour, was analyzed by real-time, quantitative RT PCR. Expression of SOCS3 is presented as arbitrary units standardized against expression of the control housekeeping gene, Pbgd. (C) Thymocytes, splenocytes, and LN cells were harvested and counted from 8- to 12-week-old wt or Socs3^ΔLck/ΔLck mice (n = 5-8). (D) Cells were pooled from inguinal, submandibular, brachial, axillary, and mesenteric LN cells from wt or Socs3^ΔLck/ΔLck mice and counted, and the lymphocyte subsets were analyzed by flow cytometry. Values shown in C and D are means (± SD) of values from 6 to 9 mice. *P < .05; **P < .01.