Linked Life Data

1915557

Source:http://linkedlifedata.com/resource/pubmed/id/1915557

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1991-11-13
pubmed:abstractText
Previously, we reported that exposure of bone marrow-derived macrophages (M phi) to a phagocytic stimulus in the simultaneous presence of interferon-gamma (IFN-gamma) induced these cells to generate nitrite (NO2-). This effect was achieved using both living (i.e. promastigotes of the protozoan parasite Leishmania enriettii) and inert (latex beads) particles. When the phagocytic stimulus was Leishmania, enhanced intracellular killing accompanied elevated NO2- secretion. As shown here, the capacity of phagocytosis to elicit NO2- production by IFN-gamma-treated M phi was inhibited by antibody to murine recombinant tumor necrosis factor-alpha (rTNF-alpha), suggesting that phagocytosis enabled IFN-gamma to activate M phi via the induction of TNF-alpha as an autocrine second signal. M phi NO2- production in response to rIFN-gamma and either exogenous TNF-alpha or Leishmania was strongly enhanced by prostaglandin E2, consistent with such a mechanism. However, addition of either Leishmania promastigotes or latex beads to M phi cultures simultaneously exposed to both IFN-gamma and exogenous murine or human rTNF-alpha further potentiated activation as measured by NO2- release. Furthermore, anti-TNF antibody failed to inhibit M phi responses to rIFN-gamma and bacterial lipopolysaccharide (LPS) in the presence or absence of Leishmania; also exogenous rTNF-alpha did not significantly affect NO2- production by IFN-gamma/LPS cultures despite a strong enhancement by Leishmania. These results suggest that phagocytosis enhances M phi responses by a process more complex than the sole induction of TNF-alpha. Phagocytosis also increased M phi NO2- production elicited by IFN-gamma plus TNF-alpha in L-arginine-deficient media. These results indicate that phagocytosis may be an important mechanism of up-regulating M phi microbicidal activity, and could be particularly relevant upon arginine depletion which occurs during an inflammatory response.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2553-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Phagocytosis enhances murine macrophage activation by interferon-gamma and tumor necrosis factor-alpha.
pubmed:affiliation
Institute of Biochemistry, Epalinges, Switzerland.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't