(A) Wild-type (Control) or Mast cell-knockout (MKO) mice received sham or vagus nerve stimulation (VNS) and LPS(6mg/Kg, ip). (B) BALB/c mice received vehicle or LPS (6mg/Kg, ip), and apoptosis in different cell types was analyzed by double-staining in FACS. (C) BALB/c mice were treated with vehicle (control) or the neutralizing anti-CD3 antibody (Anti-CD3, 20 mg/kg) 24 hrs before endotoxemia. (D) Control or nude mice received LPS, and sham surgery or vagus nerve stimulation (VNS). In all the experiments, serum TNF concentrations were analyzed at 90 mins and represented as percent of the LPS response. # represents p<0.05 vs. LPS (n=4; One-way ANOVA with Bonferroni’s corrections).