Keiko Nishimura

Immunological activity of chitin and its derivatives

The effect of chitin and its derivatives on the activation of peritoneal macrophages in vivo, on the suppression of tumour growth in syngeneic mice and on the protection of the host against bacterial infection was examined. Thirty percent deacetylated chitin (30% DA-chitin), 70% DA-chitin and carboxymethyl-chitin (CM-chitin) induced cytotoxic macrophages most effectively. Chitosan, hydroxyethyl-chitin, dihydroxypropyl-chitin (DHP-chitin) and DHP-chitosan had moderate activities. Phosphorylated-, sulphonated- or acetyl-chitin, however, were less effective. Both 70% DA-chitin and DHP-chitosan were most active on the suppression of Meth-A tumour growth in BALB/c mice, and 30% DA-chitin had a moderate effect. For the stimulation of non-specific host resistance against Escherichia coli infection, 30% and 70% DA-chitin were effective.

Adjuvant activity of chitin derivatives in mice and guinea-pigs

Adjuvant activity of chitin derivatives was examined in guinea-pigs and mice. Among derivatives of chitin tested, 30 and 70% deacetylated chitin (DAC-30 and DAC-70), were active as adjuvants for the circulating-antibody formation to bacterial alpha-amylase and for the induction of delayed-type hypersensitivity to azobenzenearsonate-N-acetyl-L-tyrosine. DAC-70 enhanced the helper T cell function, the generation of alloreactive cytotoxic T lymphocytes, and the activity of natural killer cells in mice, however, it was inactive as mitogen. Other derivatives of chitin showed weaker or no adjuvant activity compared with DAC-70. Carboxymethyl-, hydroxyethyl and dihydroxypropyl-chitin showed weak mitogenic activities on normal spleen cells.

Stimulation of cytokine production in mice using deacetylated chitin

The effect of 70% deacetylated chitin (DAC-70) on the production of cytokines in mice was examined. DAC-70 stimulated the production of colony-stimulating factor and interferon at 6 to 12 h and 24 h after intraperitoneal injection, respectively. Interleukin 1 and colony-stimulating activity were induced in the supernatants of thioglycolate-induced macrophages stimulated with DAC-70 in vitro. However, DAC-70 did not stimulate the production by spleen cells of interleukin 2, interferon, colony-stimulating or macrophage-activating factor or of interferon by macrophages in vitro. DAC-70 showed no effect on the production of tumour necrosis factor in vivo.

Bioactive chitin derivatives. Activation of mouse-peritoneal macrophages by O-(carboxymethyl)chitins.

The effect of O-(carboxymethyl)chitins (CM-chitins) on the activation of mouse-peritoneal macrophages in vivo and their mitogenic activity on mouse spleen-cells were investigated. The induction of cytotoxic macrophages is enhanced by an increase of negative charge at O-6 and decreased by further modification at O-3 of the GlcNAc residue. CM-Chitins had a minor effect on mitogenic activity that was independent of the site of modification; partially N-deacetylated chitins had little activity. Although there was remarkable enhancement of accessibility to lysozyme upon modification at O-6 of the GlcNAc residue, the accessibility was decreased by further substitution at O-3.

Stimulation of non-specific host resistance against Sendai virus and Escherichia coli infections by chitin derivatives in mice

The efficacy of chitin derivatives on non-specific host resistance to Sendai virus and Escherichia coli infections was studied in mice. Seventy percent deacetylated chitin (DAC-70) and N-trimethylated DAC-70 [DAC-70(Me)3] showed protective activity against Sendai virus infection; however, carboxymethyl-chitin (CM-chitin) did not. DAC-70 also showed protective activity against E. coli infection.

Effect of multiporous microspheres derived from chitin and partially deacetylated chitin on the activation of mouse peritoneal macrophages

Multiporous microspheres were prepared from 80% deacetylated chitin (DAC-80) and chitin, and their effects on the activation of murine peritoneal macrophages in vivo and on the production of monokines such as colony-stimulating factor (CSF) and interleukin 1 (IL-1) were examined. Multiporous DAC-80 microspheres of mean diameter 2.5 microns [MS-DAC-80(2.5)] enhanced the cytolytic activity of peritoneal macrophages and the production of CSF in vitro by macrophages, spleen cells and bone marrow cells, and in vivo. MS-DAC-80(2.5) also stimulated the production of IL-1 by both resident and thioglycolate-induced peritoneal macrophages. Multiporous chitin microspheres [MS-chitin(2.5)] showed no effect on the activation of peritoneal macrophages in vivo and on the production of IL-1 in vitro, but slightly enhanced the production of CSF in serum in vivo.

An annexin A1–FPR1 interaction contributes to necroptosis of keratinocytes in severe cutaneous adverse drug reactions

Annexin A1 secreted from drug-stimulated monocytes contributes to keratinocyte necroptosis in serious drug-related adverse events in skin. Subduing a Severe Skin Side Effect Certain pain relievers and antiepileptic drugs can cause a very rare, but sometimes fatal, side effect in which skin painfully blisters and peels, caused by the patients’ immune response to the drug. Saito et al. now find that, in susceptible patients, the drug causes secretion of the protein annexin A1 from immune cells, with deadly effect on skin cells. Annexin acts on these cells to cause necroptosis, a programmed form of cell death. The authors confirmed their results in mice, showing that an inhibitor of necroptosis blocked skin blistering. With these findings, Saito et al. lay the groundwork for a countermeasure to this dangerous side effect of otherwise extremely beneficial drugs. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening, cutaneous adverse drug reactions that are accompanied by keratinocyte cell death. Dead keratinocytes from SJS/TEN lesions exhibited necrosis, by morphological criteria. Supernatant from peripheral blood mononuclear cells (PBMCs) that had been exposed to the causative drug from patients with SJS/TEN induced the death of SJS/TEN keratinocytes, whereas supernatant from PBMCs of patients with ordinary drug skin reactions (ODSRs) exposed to the same drug did not. Keratinocytes from ODSR patients or from healthy controls were unaffected by supernatant from SJS/TEN or ODSR PBMCs. Mass spectrometric analysis identified annexin A1 as a key mediator of keratinocyte death; depletion of annexin A1 by a specific antibody diminished supernatant cytotoxicity. The necroptosis-mediating complex of RIP1 and RIP3 was indispensable for SJS/TEN supernatant–induced keratinocyte death, and SJS/TEN keratinocytes expressed abundant formyl peptide receptor 1 (FPR1), the receptor for annexin A1, whereas control keratinocytes did not. Inhibition of necroptosis completely prevented SJS/TEN-like responses in a mouse model of SJS/TEN. Our results demonstrate that a necroptosis pathway, likely mediated by annexin 1 acting through the FPR1 receptor, contributes to SJS/TEN.

Immunological Activity of Chitin Derivatives

Previously, we have reported the immunological activities of chitin derivatives for the stimulation of non-specific host resistance in mice.1 Among derivatives of chitin tested, deacetylated chtin derivatives such as 70% deacetylated chitin (DAC-70) and 30% deacetylated chitin (DAC-30) were shown to have potent immunological activities for activation of peritoneal macrophages in vivo, suppression of Meth-A tumor cells in syngeneic BALB/c mice and stimulation of non-specific host resistance against Escherichia coli infection in mice. Recently, Suzuki et al.2,3 have reported that chitin and chitosan were effective for the protection of host against infection with Candida albicans and Staphylococcus aureus and against growth of Ehrlich and Sarcoma 180 ascites tumor.

Syntheses of Trehalose Monomycolate and Related Compounds, and Their Lethal Toxicity and Adjuvant Activity

Abstract Five monoesters, 6-O-mycoloyl-α, α-treha lose (TMM), 6-O-mycoloyl-D-glucose (GlcM), 6-O-mycoloyl-N-acetyl-D-glucosamine (GlcNAcM), 5-O-mycoloyl-D-arabinose (AraM) and 6-O-mycoloyl-D-galactose (GalM), were synthesized by use of mycolic acid isolated from Mycobacterium tuberculosis strain Aoyama B. Their toxicity and macrophage activating ability were examined in mice. A single intravenous administration of 400 μg of TMM in 9% oil-in-water emulsion killed 8 of 8 treated mice. The other analogs showed less lethal toxicity to mice at the same dose. Tumoricidal activity of mouse peritoneal macrophages was induced by intraperitoneal injection of TMM, GlcM, and GlcNAcM, respectively.

Mucocutaneous pyoderma gangrenosum due to trisomy 8 neutrophilic infiltrates in a patient with myelodysplastic syndrome

1 Schneider MR. Genetic mouse models for skin research: strategies and resources. Genesis 2012; 50:652–64. 2 Summerfield A, Meurens F, Ricklin ME. The immunology of the porcine skin and its value as a model for human skin. Mol Immunol 2015; 66:14–21. 3 Gray GM, Yardley HJ. Lipid compositions of cells isolated from pig, human, and rat epidermis. J Lipid Res 1975; 16:434–40. 4 Dmochewitz M, Wolf E. Genetic engineering of pigs for the creation of translational models of human pathologies. Animal Frontiers 2015; 5:50–6. 5 McCalla-Martin AC, Chen X, Linder KE et al. Varying phenotypes in swine versus murine transgenic models constitutively expressing the same human Sonic hedgehog transcriptional activator, K5HGLI2 Delta N. Transgenic Res 2010; 19:869–87. 6 Wang Y, Yang HQ, Jiang W et al. Transgenic expression of human cytoxic T-lymphocyte associated antigen4-immunoglobulin (hCTLA4Ig) by porcine skin for xenogeneic skin grafting. Transgenic Res 2015; 24:199–211. 7 O’Brien K, Bhatia A, Tsen F et al. Identification of the critical therapeutic entity in secreted Hsp90alpha that promotes wound healing in newly re-standardized healthy and diabetic pig models. PLOS ONE 2014; 9:e113956. 8 Renner S, Braun-Reichhart C, Blutke A et al. Permanent neonatal diabetes in INS transgenic pigs. Diabetes 2013; 62:1505–11. 9 Abbott A. Inside the first pig biobank. Nature 2015; 519:397–8. 10 Renner S, Fehlings C, Herbach N et al. Glucose intolerance and reduced proliferation of pancreatic beta-cells in transgenic pigs with impaired glucose-dependent insulinotropic polypeptide function. Diabetes 2010; 59:1228–38. 11 Chamcheu JC, Siddiqui IA, Syed DN et al. Keratin gene mutations in disorders of human skin and its appendages. Arch Biochem Biophys 2011; 508:123–37.