Lymphocytes modulate peritoneal leukocyte recruitment in peritonitis

Objective and design  To investigate the modulating role of lymphocytes in leukocyte recruitment in a murine model of peritonitis. Materials or subjects  RAG-1 knockout (KO) mice, NUDE mice and μMT KO mice were compared to their wild-type controls. Treatment  Mice were administered with 1 ml of Brewer’s thioglycollate (BTG) and terminal peritoneal lavages were performed at 8, 24, 72 and 120 h after treatment. Methods  Leukocyte numbers recruited at the different time points following a BTG administration were determined. Chemokine and cytokine levels were assessed by either ELISAs or cytometric bead array. Results  RAG-1 KO mice (absent B and T cells) exhibited increased early neutrophil infiltration and blunted late monocyte/macrophage infiltration. NUDE mice (absent T cells) exhibited both increased neutrophil and monocyte/macrophage infiltration. In contrast, μMT KO mice (absent B cells) demonstrated reduced influx of both neutrophils and monocyte/macrophages. Chemokine analysis revealed various differences in important chemokines. Conclusions  These data suggest that T cells act to suppress leukocyte recruitment while B cells promote leukocyte recruitment. J. Hughes and J.-F. Cailhier are joint senior authors.