Role of lymphocytes in the course of murine zymosan-induced peritonitis

. Objective and Design: To investigate a putative role of lymphocytes in a murine model of zymosan peritonitis. Material or Subjects: Rag-deficient mice (KO) and their counterparts (WT) (13 animals in each group). Treatment: Mice were injected i. p. with zymosan (2 mg/ml, 0.5 ml/mouse) and sacrificed either 30 min or 6 h post-treatment. Methods: At 30 min of inflammation vascular permeability was assessed by peritoneal leakage of i. v. injected Evans blue. At 6 h of peritonitis leukocyte numbers were estimated (Turk’s staining), and MMP-2 and -9 presence (zymography). Levels of inflammatory mediators were evaluated by either ELISA (PGE 2 , KC) or Cytometric Bead Array (IL-6, IL-10, MCP-1, IFN- γ , TNF-α, and IL-12p70). The Amount of nitric oxide (NO) was measured by the Greiss reaction. Differences between WT and KO mice were analyzed by Student’s t-test (p ≤0.05). Results: During zymosan peritonitis, there was a decreased production of IFN-α (p = 0.03) and IL-10 (p = 0.03) and elevated synthesis of NO (p = 0.0001) in KO mice compared with WT controls. Despite this, no alterations in major events of peritonitis (vascular permeability and neutrophil infiltration) were detected in KO mice. Conclusions: Lymphocytes do not have a significant impact on zymosan peritonitis in mice.