Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1996-2-26
|
| pubmed:abstractText |
Mycobacterium avium is a facultative intracellular pathogen that can survive and replicate within macrophages. We tested the hypotheses that survival mechanisms may include alteration of phagosomal pH or inhibition of phagosome-lysosome fusion. M. avium was surface labeled with N-hydroxysuccinimidyl esters of carboxyfluorescein (CF) and rhodamine (Rho) to enable measurement of the pH of individual M. avium-containing phagosomes and the interactions of bacterium-containing phagosomes with labeled secondary lysosomes. CF fluorescence is pH sensitive, whereas Rho is pH insensitive; pH can be calculated from their fluorescence ratios. Surface labeling of M. avium did not affect viability in broth cultures or within J774, a murine macrophage-like cell line. By fluorescence spectroscopy, live M. avium was exposed to an environmental pH of approximately 5.7 at 6 h after phagocytosis, whereas similarly labeled Salmonella typhimurium, zymosan A, or heat-killed M. avium encountered an environmental pH of < 5.0. Video fluorescence and laser scanning confocal microscopy gave consistent pH results and demonstrated the heterogeneity of intracellular fate early in infection. pH became more homogeneous 6 h after infection. M. avium cells were coated with immunoglobulin G (IgG) or opsonized to investigate whether phagocytosis by the corresponding receptors would alter intracellular fate. Opsonized, unopsonized, and IgG-coated M. avium cells entered compartments of similar pH. Finally, the spatial distribution of intracellular bacteria and secondary lysosomes was compared. Only 18% of live fluorescent M. avium cells colocalized with fluorescent lysosomes, while 98% of heat-killed bacteria colocalized. Thus, both inhibition of phagosome-lysosome fusion and alteration of phagosomal pH may contribute to the intracellular survival of M. avium.
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| pubmed:grant | |
| pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-14020151,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-1438196,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-1476803,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-1826895,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-1902198,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-2037799,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-2200126,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-2574457,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-2779443,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-28524,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-2860567,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-3283260,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-6144684,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-6181075,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-6183281,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-6501409,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-807671,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8557358-8303277
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
|
| pubmed:issn |
0019-9567
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
64
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
319-25
|
| pubmed:dateRevised |
2009-11-18
|
| pubmed:meshHeading |
pubmed-meshheading:8557358-Animals,
pubmed-meshheading:8557358-Cell Line,
pubmed-meshheading:8557358-Fluoresceins,
pubmed-meshheading:8557358-Fluorescent Dyes,
pubmed-meshheading:8557358-Hydrogen-Ion Concentration,
pubmed-meshheading:8557358-Lysosomes,
pubmed-meshheading:8557358-Macrophages,
pubmed-meshheading:8557358-Membrane Fusion,
pubmed-meshheading:8557358-Mice,
pubmed-meshheading:8557358-Microscopy, Video,
pubmed-meshheading:8557358-Mycobacterium avium,
pubmed-meshheading:8557358-Opsonin Proteins,
pubmed-meshheading:8557358-Phagosomes,
pubmed-meshheading:8557358-Rhodamines,
pubmed-meshheading:8557358-Salmonella typhimurium,
pubmed-meshheading:8557358-Spectrometry, Fluorescence
|
| pubmed:year |
1996
|
| pubmed:articleTitle |
Intracellular fate of Mycobacterium avium: use of dual-label spectrofluorometry to investigate the influence of bacterial viability and opsonization on phagosomal pH and phagosome-lysosome interaction.
|
| pubmed:affiliation |
Department of Pharmaceutics, State University of New York at Buffalo, Amherst 14260, USA.
|
| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.
|