Electron-microscopic and biochemical studies on motphological changes in Staplrylococcus aureus following exposure to protein synthesis inhibitory agents such as lineomycin (LCM), clindamycin (CLM), eiythromycin (EM), and spiramycin (SP) are presented in this paper. It was demonstrated that bacterial cell walls beeanne extremly thickened usually with the formation of multilayers, when exposed to eaeh of the ahove-mentioned antibiotics. Furthermorc. electron density of the cytoplasm was higher in thosc cells exposed to drugs than in intact control cells. Incorporations of 41C-labeled L lysine into the cell-wall fraction and the protein fraction were measured for biochemical elucidation of these phenomena. Labeled lysine was selectively incorporated into the cell-wall fraetion when the test organism was exposed to the respective antibiotics. Uptake at 15min after exposure was about twice as large as that of intact control cells. SP and CLM inhibited protein synthesis while they stimulated cell-wall synthcsis. The evidences for thickening of, and formation of multilaycrs in the bacterial cell walls following exposure to drugs were elosely related to the slimulating action of these antibiotics on the cell-wall synthesizing system. Morphology of resistant clinical isolates following such antibiotic exposure was also investigated using two staphyloeoccal strains, one resistant to EM alone and the other completcly cross-resistant to all the macrolides.

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  We report here the isolation and characterization of a peptide-N⁴-(acetyl-β-glucosaminyl) asparagine amidase (peptide: N-glycanase) from soybean (Glycine max) seeds. The enzyme was purified to homogeneity with 6.5% yield from defatted soybean meal extract by ion-exchange chromatography, gel filtration, hydroxyapatite chromatography, and hydrophobic chromatography. The purified enzyme, designated PNGase-GM, had the apparent molecular mass of 93 kDa by SDS-PAGE and 90 kDa by gel filtration, indicating this PNGase is a monomeric protein. The enzyme showed maximal activity at pH 4.5-5.0. PNGase-GM was capable of hydrolyzing the β-aspartylglycosylamine linkage (GlcNAcβ1→Asn) of various glycopeptide substrates bearing high-mannose type, hybrid type, and xylose/fucose-containing plant complex type N-glycan units, while this amidase was far less active on the glycopeptides bearing sialylated animal complex-type glycans.

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Toll様受容体(TLR)は樹状細胞にレパトアで発現し，微生物成分を認識して転写因子NF-κBやIRF-3を活性化する。樹状細胞応答としてサイトカインとI型interferon (IFN)を誘導する。また，TLR刺激は樹状細胞を成熟化に導き，CTL, NKの活性化を誘起する。TLRによるこれらのエフェクター誘導の機序は不明である。マウス移植がんの系を用いるとCTL, NK依存性の抗がん免疫活性を分別測定できる。われわれはTLR2/4をBCG-CWSで刺激することでMyD88アダプター依存性にCTLが誘導されること，TLR3をpolyI:Cで刺激することでTICAM-1依存性にNKが誘導されることを本研究で明らかにした。この応答には樹状細胞のTLR-アダプター経路が重要である。樹状細胞がアジュバント要求性にさまざまな成熟化模様を呈するのはTLRのシグナル経路に依存することと推定される。毒性の少ない誘導体の開発が望ましいが，BCG-CWS, polyI:Cは樹状細胞療法のアジュバントとして抗がん免疫療法などの臨床応用に有用である。

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