Fourier-transform detection of singlet oxygen and fluorescence from cell membrane bound porphyrins

1994 ◽  
Vol 90 (17) ◽  
pp. 2453-2454 ◽  
Author(s):  
Fritz Böhm ◽  
George Marston ◽  
T. George Truscott ◽  
Richard P. Wayne
Keyword(s):  
Fourier Transform ◽  
Cell Membrane ◽  
Singlet Oxygen ◽  
Membrane Bound

scholarly journals Two Atypical Enteropathogenic Escherichia coli Strains Induce the Production of Secreted and Membrane-Bound Mucins To Benefit Their Own Growth at the Apical Surface of Human Mucin-Secreting Intestinal HT29-MTX Cells

2010 ◽  
Vol 78 (3) ◽  
pp. 927-938 ◽  
Author(s):  
Mônica A. M. Vieira ◽  
Tânia A. T. Gomes ◽  
Antonio J. P. Ferreira ◽  
Terezinha Knöbl ◽  
Alain L. Servin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Brush Border ◽  
Apical Surface ◽  
Enteropathogenic Escherichia Coli ◽  
Typical Epec ◽  
Membrane Bound

ABSTRACT In rabbit ligated ileal loops, two atypical enteropathogenic Escherichia coli (aEPEC) strains, 3991-1 and 0421-1, intimately associated with the cell membrane, forming the characteristic EPEC attachment and effacement lesion of the brush border, induced a mucous hypersecretion, whereas typical EPEC (tEPEC) strain E2348/69 did not. Using cultured human mucin-secreting intestinal HT29-MTX cells, we demonstrate that apically aEPEC infection is followed by increased production of secreted MUC2 and MUC5AC mucins and membrane-bound MUC3 and MUC4 mucins. The transcription of the MUC5AC and MUC4 genes was transiently upregulated after aEPEC infection. We provide evidence that the apically adhering aEPEC cells exploit the mucins' increased production since they grew in the presence of membrane-bound mucins, whereas tEPEC did not. The data described herein report a putative new virulence phenomenon in aEPEC.

The Proinflammatory Cytokine Interleukin-12 Occurs as a Cell Membrane-Bound Form on Macrophages

1996 ◽  
Vol 225 (3) ◽  
pp. 1063-1067 ◽  
Author(s):  
Xiaohong Fan ◽  
Vladimir Sibalic ◽  
Eva Niederer ◽  
Rudolf P. Wüthrich
Keyword(s):  
Cell Membrane ◽  
Proinflammatory Cytokine ◽  
Interleukin 12 ◽  
A Cell ◽  
Membrane Bound

CD40 ligand gene therapy directly induces apoptosis in carcinomas

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14082-14082 ◽  
Author(s):  
D. H. Palmer ◽  
T. El-Metwali ◽  
A. E. Milner ◽  
E. Hodgkin ◽  
L. S. Young
Keyword(s):  
Protein Synthesis ◽  
Cell Membrane ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Membrane Expression ◽  
Cd40 Ligation ◽  
Potent Inducer ◽  
Tumour Immunity ◽  
Soluble Ligand ◽  
Membrane Bound

14082 Background: CD40 is a member of the TNFReceptor superfamily expressed on a variety of immune cells. Interaction of CD40 with its ligand (CD40L) plays a key role in orchestrating immune responses. We have shown that CD40 is also expressed on a variety of carcinomas. CD40 ligation in this context can induce cancer cell death. Thus CD40 represents a rational target with direct cytotoxicity and induction of anti-tumour immunity. Methods: We generated an adenovirus encoding CD40L (AdCD40L) and investigated its effect in CD40-expressing carcinoma cells (bladder, ovary, hepatocellular) as follows:(i)comparison of Ad-delivered CD40L with recombinant soluble ligand (rsCD40L);(ii)inhibition of cleavage of CD40L from the cell membrane using metalloproteinase inhibitors (MMPI);(iii)generation of a mutant CD40L resistant to MMP cleavage. Results: (i)CD40 ligation in carcinomas stimulates survival and apoptotic signaling. rsCD40L is only cytotoxic in the presence of protein synthesis inhibition, which blocks survival pathways and allows apoptosis. In contrast, AdCD40L is cytotoxic even in the absence of protein synthesis inhibitor;(ii)AdCD40L results in expression at the cell membrane but this is cleaved from the membrane and detected as soluble ligand in supernatant of infected cells. Cleavage is inhibited by MMPI and this increases apoptosis, suggesting that membrane-bound CD40L is a more potent apoptotic stimulus than soluble ligand;(iii)we identified the cleavage site of CD40L and generated a mutant by deletion of this region and cloned this mCD40L into an adenovirus. AdmCD40L results in membrane expression of CD40L, with no detectable soluble CD40L, confirming its resistance to cleavage. AdmCD40L is significantly more cytotoxic than wild-type AdCD40L. Conclusions: The effect of CD40 ligation depends on the cellular context and the method of CD40L delivery: adenovirus delivery results in membrane-bound expression and this provides a stronger apoptotic stimulus than rsCD40L. Apoptosis is further enhanced by a mutant CD40L that is resistant to cleavage from the cell membrane. Thus AdmCD40L is a novel therapeutic that is a potent inducer of apoptosis. Studies are underway to assess these effects in vivo and to elucidate the contribution of immunostimulatory effects in syngeneic models. No significant financial relationships to disclose.

Copper and nickel uptake and accumulation, and their effects on redox and electrical potentials of hepatopancreatic cells of Oniscus asellus Linnaeus (Porcellionidae, Isopoda)

1990 ◽  
Vol 68 (4) ◽  
pp. 651-655 ◽  
Author(s):  
M. A. Alikhan ◽  
V. Storch
Keyword(s):  
Catalytic Activity ◽  
Cell Membrane ◽  
Membrane Surface ◽  
Dry Weight ◽  
Body Tissue ◽  
Electrical Potentials ◽  
Nickel Uptake ◽  
Membrane Bound ◽  
Total Body ◽  
Cell Membrane Surface

Highest tissue Cu concentrations (1728 μg∙g dry weight−1) in whole Oniscus asellus, reared for 7 days on carrot powder containing 50 μg Cu∙g dry weight−1, 10 μg Ni∙g dry weight−1, or a mixture of 50 μg Cu and 10 μg Ni∙g dry weight−1, were observed in isopods on 50 μg Cu∙g dry weight−1, and lowest (917 μg∙g dry weight−1) in those on 10 μg Ni∙g dry weight−1. Highest Ni concentrations (277 and 272 μg∙g dry weight−1) were present in isopods fed on a mixture of 50 μg Cu and 10 μg Ni∙g dry weight−1 and 10 μg Ni∙g dry weight−1, respectively, and lowest (201 μg∙g dry weight−1) in those on 50 μg Cu∙g dry weight−1. Of the total body-tissue Cu, 8–66% was contained in membrane-bound vesicles of hepatopancreatic S-cells, and 73–89% of Ni was present inside the lumen and within S-cells of the hepatopancreas. The presence of Ni in the diet appeared to adversely affect the absorption and hepatopancreatic storage of Cu. Copper slightly enhanced, and nickel drastically reduced, the hepatopancreatic redox (= catalytic activity) and cell-membrane surface potentials. The significance of these findings is discussed.

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