Fig. 5.

Signaling analysis of Cd22^–/– B cells. a CD22 deficiency results in different spectrum of NF-κB activation. DNA binding activity of the NF-κB subunits, p50, p52, p65 and RelB in the nuclear extracts from WT and Cd22^–/– B cells was assayed by ELISA using oligonucleotides containing the NF-κB-binding site and specific antibodies to each subunit. b Impaired induction of SOCS1 and 3 in Cd22^–/– B cells upon CpG stimulation. Total RNA was extracted from 1.0 × 10⁷ of B cells from WT or Cd22^–/– B cells stimulated with 250 n M CpG for 3 h or unstimulated. Expression of SOCS1 and 3 was examined by quantitative real-time PCR. Expression levels were normalized to β-actin. Statistical analyses were performed by Student's t test. Data are representative of 2 independent experiments with similar results.