A crucial role for TNF-α in mediating neutrophil influx induced by endogenously generated or exogenous chemokines,KC/CXCL1 and LIX/CXCL5

Background and purpose:

Chemokines orchestrate neutrophil recruitment to inflammatory foci. In the present study, we evaluated the participation of three chemokines, KC/CXCL1, MIP-2/CXCL2 and LIX/CXCL5, which are ligands for chemokine receptor 2 (CXCR2), in mediating neutrophil recruitment in immune inflammation induced by antigen in immunized mice.

Experimental approach:

Neutrophil recruitment was assessed in immunized mice challenged with methylated bovine serum albumin, KC/CXCL1, LIX/CXCL5 or tumour necrosis factor (TNF)-α. Cytokine and chemokine levels were determined in peritoneal exudates and in supernatants of macrophages and mast cells by elisa. CXCR2 and intercellular adhesion molecule 1 (ICAM-1) expression was determined using immunohistochemistry and confocal microscopy.

Key results:

Antigen challenge induced dose- and time-dependent neutrophil recruitment and production of KC/CXCL1, LIX/CXCL5 and TNF-α, but not MIP-2/CXCL2, in peritoneal exudates. Neutrophil recruitment was inhibited by treatment with reparixin (CXCR1/2 antagonist), anti-KC/CXCL1, anti-LIX/CXCL5 or anti-TNF-α antibodies and in tumour necrosis factor receptor 1-deficient mice. Intraperitoneal injection of KC/CXCL1 and LIX/CXCL5 induced dose- and time-dependent neutrophil recruitment and TNF-α production, which were inhibited by reparixin or anti-TNF-α treatment. Macrophages and mast cells expressed CXCR2 receptors. Increased macrophage numbers enhanced, while cromolyn sodium (mast cell stabilizer) diminished, LIX/CXCL5-induced neutrophil recruitment. Macrophages and mast cells from immunized mice produced TNF-α upon LIX/CXCL5 stimulation. Methylated bovine serum albumin induced expression of ICAM-1 on mesenteric vascular endothelium, which was inhibited by anti-TNF-α or anti-LIX/CXCL5.

Conclusion and implications:

Following antigen challenge, CXCR2 ligands are produced and act on macrophages and mast cells triggering the production of TNF-α, which synergistically contribute to neutrophil recruitment through induction of the expression of ICAM-1.     

The effect of Nigella sativa alone, and in combination with dexamethasone, on tracheal muscle responsiveness and lung inflammation in sulfur mustard exposed guinea pigs

Ethnomedical relevance

The anti-inflammatory activity of both systemic and local administrations of essential oil from Nigella sativa L. has been shown.

Aim of the study

Therefore, the effect of Nigella sativa on tracheal responsiveness (TR) and lung inflammation of sulfur mustard (SM) exposed guinea pigs was examined.

Materials and methods

Guinea pigs were exposed to diluent solution (control group), inhaled SM (SME group), SME treated with Nigella sativa (SME + N), SME treated with dexamethasone (SME + D) and SME treated with both drugs (SME + N + D), (n = 7 for each group). TR to methacholine, total white blood cell (WBC) and differential WBC count of lung lavage, and serum cytokines were measured 14 days post-exposure.

Results

The values of TR, eosinophil, monocyte, lymphocyte, interleukine-4 (IL-4) and interferon gamma (IFN-γ) of SME group were significantly higher than those of controls (p < 0.05 to p < 0.001). The TR in SME + N, SME + D and SME + N + D was significantly lower compared to that of SME group (p < 0.01 for all cases). The percentage of eosinophil in SME + D, and the percentage of monocyte in SME + N + D (p < 0.05 to p < 0.01) were significantly lower than those in SME group. The neutrophil number was decreased in SME + N and SME + N + D groups compared to SME animals (p < 0.05 to p < 0.01). IL-4 levels in serum of SME + N (p < 0.01), SME + D (p < 0.05), SME + N + D (p < 0.01) and IFN-γ in SME + N (p < 0.05) were greater than those in SME animals.

Conclusions

These results showed a preventive effect of Nigella sativa on TR and lung inflammation of SM exposed guinea pigs.     

The effect of carvacrol on muscarinic receptors of guinea‐pig tracheal chains

The effects of three concentrations of carvacrol, the constituent of Zataria multiflora Boiss (a monoterpenoid phenol, C₁₀H₁₄O) and 10 nm atropine on muscarinic receptors were tested on: non‐incubated (n = 7), incubated tracheal chains with propranolol and chlorpheniramine (n = 6) and incubated with propranolol (n = 5). The EC₅₀ of all three concentrations of carvacrol in incubated tissues with propranolol and chlorpheniramine was significantly greater than those of incubated tissues with propranolol and non‐incubated trachea (p < 0.05 to p < 0.001). The EC₅₀ of two higher concentrations of carvacrol (0.2 and 0.4 µg/mL) in incubated tissues with propranolol was also significantly greater than those of non‐incubated trachea (p < 0.01 to p < 0.001). The maximum response in the presence of all concentrations of carvacrol in non‐incubated and incubated tissues with propranolol and chlorpheniramine and those of its two higher concentrations (0.2 and 0.4 µg/mL) in incubated tissues with propranolol were lower than saline (p < 0.05 to p < 0.001). There were parallel rightward shifts in the concentration–response curves in the presence of all concentrations of carvacrol in non‐incubated and incubated tissues with propranolol and its lower concentration in incubated tissues with propranolol and chlorpheniramine. These results indicated an inhibitory effect of carvacrol on muscarinic receptors. A β‐adrenoceptor stimulatory effect was also suggested for carvacrol. Copyright © 2010 John Wiley & Sons, Ltd.     

Acute generalized exanthematous pustulosis due to thallium

Acute generalized exanthematous pustulosis (AGEP) is characterized clinically by fever, pruritus and acute pustular eruption. Usually a drug is found to be the responsible agent. We present a patient who experienced an acute generalized exanthematous pustulosis due to radioactive thallium. The eruption cleared rapidly after discontinuation of the drug and systemic corticosteroid therapy.     

A phase I study of sequential versus concurrent interleukin-3 and granulocyte-macrophage colony-stimulating factor in advanced breast cancer patients treated with FLAC (5-fluorouracil, leucovorin, doxorubicin, cyclophosphamide) chemotherapy

Cumulative thrombocytopenia is a dose-limiting toxicity of dose- intensive chemotherapy for advanced breast cancer. In this phase I study, we have studied the hematologic toxicity associated with sequential interleukin-3 (IL-3) and granulocyte-macrophage colony- stimulating factor (GM-CSF; molgramostim) administration after multiple cycles of FLAC (5-fluorouracil, leucovorin, doxorubicin, cyclophosphamide) chemotherapy compared with that after concurrent cytokine administration or to each cytokine administered alone. Ninety- three patients with advanced breast cancer were treated with five cycles of FLAC chemotherapy and either IL-3 alone, GM-CSF alone, sequential IL-3 and GM-CSF administered by schedule A (5 days of IL-3 followed by 10 days of GM-CSF) or schedule B (9 days of IL-3 followed by 6 days of GM-CSF), or concurrent administration of IL-3 and GM-CSF for 15 days. Cohorts of patients were treated with one of four dose levels of IL-3 (1,2.5, 5, and 10 micrograms/kg) administered subcutaneously for each schedule of cytokine administration. The GM-CSF dose in all schedules was 5 micrograms/kg/day. Sequential IL-3 and GM- CSF (schedule B) was associated with higher platelet nadirs, shorter durations of platelet counts less than 50,000/microL, and the need for fewer platelet transfusions over five cycles of FLAC chemotherapy compared with concurrent cytokines, sequential IL-3 and GM-CSF schedule A, and GM-CSF alone. Concurrent IL-3 and GM-CSF was associated with unexpected platelet toxicity. The duration of granulocytopenia after FLAC chemotherapy was significantly worse with IL-3 alone compared with each of the GM-CSF-containing cytokine regimens. Although no cycle 1 maximum tolerated dose for IL-3 was defined in this study, 5 micrograms/kg was well tolerated over multiple cycles of therapy and is recommended for future studies. The data from this phase I study suggest that sequential IL-3 and GM-CSF with IL-3 administered for 9 days before beginning GM-CSF may be superior to shorter durations of IL- 3 administered sequentially with GM-CSF, to concurrent IL-3 and GM-CSF, and to either colony-stimulating factor alone in ameliorating the cumulative hematologic toxicity associated with multiple cycles of FLAC chemotherapy. Additional studies of sequential IL-3 and GM-CSF are warranted.     

Diamond-Blackfan syndrome: evidence against cell-mediated erythropoietic suppression

The profound anemia of Diamond-Blackfan syndrome (DBS) is due to marrow red cell failure, but the pathogenesis is not understood. Studies by others indicated cell-mediated erythropoietic suppression in this condition. To explore this mechanism further, Ficoll-Hypaque--separated peripheral blood lymphocytes (PBL) from four anemic untreated patients with DBS, or from normals were cocultured with control marrow in vitro and the growth of erythropoietin-responsive stem cell colonies (CFU-E) was dermined. CFU-E numbers obtained from cultures with added normal PBL were not significantly different from the number without PBL. Similarly, CFU-E from cultures with added DBS PBL were not significantly different from the number without PBL (215 versus 220, 229 versus 220 and 84 versus 60, 74 versus 94/10(5) cells, respectively). Mixing marrows from a control and one DBS patient in ratios of 2:1, 1:1, or 1:2 prior to culture failed to disclose a decrease of colony growth. We could not show cellular inhibition of erythropoiesis in these patients with DBS. The mechanism of anemia in this disorder remains an open question.     

Invasion of erythrocytes by Plasmodium falciparum malaria parasites: evidence for receptor heterogeneity and two receptors

Plasmodium falciparum malaria parasites with different capabilities of invading sialic acid-deficient erythrocytes were identified. Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase-treated and Tn erythrocytes twice as efficiently as Thai-2 parasites cultured in normal erythrocytes and seven to ten times more efficiently than a cloned line of Camp parasites cultured in normal erythrocytes. All three parasite lines required sialic acid for optimal invasion, but Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase- treated erythrocytes with 45% efficiency whereas Camp parasites invaded neuraminidase-treated erythrocytes with less than 10% efficiency. P falciparum malaria parasites probably possess two receptors: one that binds to a sialic acid-dependent ligand and another that binds to a sialic acid-independent ligand. Parasites may differ in the quantity or affinity of their receptors for the sialic acid-independent ligand.