g(m1)-ganglioside and Peritonitis

This study examined whether NK cells are important for resolution of antigen-induced inflammation. C57BL/6 mice were immunized twice with methylated BSA (mBSA) and inflammation induced by intraperitoneal injection of mBSA. Mice were injected intravenously with anti-asialo GM1 (αASGM1) or a control antibody 24h prior to peritonitis induction and peritoneal exudate collected at different time points. Expression of surface molecules and apoptosis on peritoneal cells was determined by flow cytometry and concentration of chemokines, cytokines, soluble cytokine receptors and lipid mediators by ELISA and LC-MS/MS. Apoptosis in parathymic lymph nodes and spleens was determined by TUNEL staining. Mice administered αASGM1 had lower peritoneal NK cell numbers and a higher number of peritoneal neutrophils 12h after induction of inflammation than control mice. The number of neutrophils was still high in the αASGM1 treated mice when their number had returned to baseline levels in the control mice, 48h after induction of inflammation. Peritoneal concentrations of the neutrophil regulators G-CSF and IL-12p40 were higher at 12h in the αASGM1 treated mice than in the control mice, whereas concentrations of lipid mediators implicated in resolution of inflammation, i.e. LXA

Topics: Animals; Antibodies; Antigens; Apoptosis; Chemokines; Dinoprostone; Female; G(M1) Ganglioside; Granulocyte Colony-Stimulating Factor; Immunophenotyping; Inflammation Mediators; Interleukin-12 Subunit p40; Killer Cells, Natural; Lipoxins; Lymph Nodes; Mice; Mice, Inbred C57BL; Neutrophil Infiltration; Peritonitis; Receptors, Natural Killer Cell; Serum Albumin, Bovine; Spleen

Natural killer (NK) cells have a well-established role in host defense against viral infections and malignancies. However, their function in bacterial infection and sepsis is poorly defined. We hypothesized that NK cells, as a major producer of interferon-gamma during sepsis, would be important in host defense against bacterial infections. Cecal ligation and puncture (CLP) was performed on Swiss Webster mice depleted of NK cells by pretreatment with anti-asialo GM1 and control mice given immunoglobulin G (IgG) antibody. NK cell-depleted mice had significantly higher anaerobic bacterial counts in the liver and peritoneal lavage fluid, as well as higher aerobic counts in the liver and blood 4 h after CLP. Macrophage phagocytosis, nitric oxide production, and interleukin (IL)-6 levels at 4 h were also decreased in mice depleted of NK cells compared with controls. Greater neutrophil influx into the peritoneum, indicated by higher myeloperoxidase levels, was also seen in NK cell-depleted mice. At 8 and 18 h after CLP, bacterial counts were similar between groups, and overall survival rates were not significantly different. Peritoneal IL-12 levels significantly increased by 18 h in normal mice, but not in NK cell-depleted animals. Our data suggest that NK cells participate in the early local and systemic eradication of bacteria and regulation of IL-12 during polymicrobial sepsis. These effects are likely due to their interactions with macrophages.

Topics: Animals; Bacteria; Cell Movement; Chemokine CXCL2; Flow Cytometry; G(M1) Ganglioside; Inflammation; Interleukin-6; Killer Cells, Natural; Macrophages; Mice; Monokines; Neutrophils; Nitric Oxide; Peritonitis; Peroxidase; Phagocytosis; Sepsis; Time Factors

beta 2 microglobulin knockout (beta2M-/-) mice lack CD8+ T and natural killer T cells. We hypothesized that beta 2M-/- mice are resistant to lethal intraabdominal sepsis. To test this hypothesis, mortality, cytokine production, and physiologic function were assessed in beta 2M-/- mice during sepsis caused by cecal ligation and puncture (CLP). beta 2M-/- mice survived significantly longer than wild-type mice after CLP but ultimately exhibited 100% mortality. Treatment of beta 2M-/- mice with anti-asialoGM1 to deplete natural killer cells conferred greater than 70% long-term survival. Compared with wild-type mice, beta 2M-/- mice treated with anti-asialoGM1 produced decreased amounts of proinflammatory cytokines and did not exhibit hypothermia or metabolic acidosis after CLP. Adoptive transfer of CD8+ T and natural killer cells into beta 2M-/- mice treated with anti-asialoGM1 re-established CLP-induced mortality. CD8 knockout mice treated with anti-asialoGM1, which are specifically deficient in CD8+ T and natural killer cells, exhibited 40% long-term survival after CLP. Furthermore, treatment of wild-type mice with antibodies to CD8 and asialoGM1 conferred a significant survival benefit compared with wild-type mice treated with nonspecific IgG. These findings demonstrate that beta 2M-/- mice treated with anti-asialoGM1 are resistant to CLP-induced mortality and that depletion of CD8+ T and natural killer cells largely accounts for the survival benefit observed in these mice.

Topics: Adoptive Transfer; Animals; beta 2-Microglobulin; CD8-Positive T-Lymphocytes; Cecum; Disease Models, Animal; Female; G(M1) Ganglioside; Immunity, Innate; Inflammation; Killer Cells, Natural; Ligation; Lymphopenia; Mice; Mice, Inbred C57BL; Mice, Knockout; Peritonitis; Sepsis; Survival Analysis

Gangliosides (GA) have been shown to promote axonal sprouting and growth of injured peripheral nerves, and enhance functional biochemical and morphologic recovery after CNS damage. Moreover, it has recently been shown that the natural ganglioside mixture (GM1 + GD1a + GD1b + GT1b) from bovine brain is endowed with powerful anti-inflammatory activity in rodents. Here we report that the novel semisynthetic ganglioside derivative AGF44, the isopropyl ester of monosialoganglioside GM1, displays a potent anti-inflammatory activity when orally or topically administered in various models of acute inflammation. AGF44 was effective (0.5-5 mg/kg p.o. or 0.5% gel topical application) in reducing rat paw oedema induced by either carrageenin, histamine, bradykinin, serotonin, nystatin or kaolin. Moreover, crossed confrontation with the effects elicited by other anti-inflammatory agents revealed that AGE44 seems to act through a different pathway than NSAIDs, steroids or antihistaminic/antiserotoninic agents.

Topics: Administration, Oral; Administration, Topical; Animals; Anti-Inflammatory Agents, Non-Steroidal; Drug Evaluation, Preclinical; G(M1) Ganglioside; Inflammation; Male; Mice; Peritonitis; Rats; Rats, Sprague-Dawley