These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Interleukin-1 upregulates anaphylatoxin receptors on mononuclear cells.
    Author: Takabayashi T, Shimizu S, Clark BD, Beinborn M, Burke JF, Gelfand JA.
    Journal: Surgery; 2004 May; 135(5):544-54. PubMed ID: 15118592.
    Abstract:
    BACKGROUND: The anaphylatoxins, C3a and C5a, that are generated during trauma, major surgery, or infection are potent proinflammatory mediators that increase interleukin (IL-1) cytokine synthesis. We investigated the effects of IL-1 on anaphylatoxin receptor expression in monocytes. METHODS: A human monocytic cell line, MONO-MAC-6, was used. C3a and C5a binding sites were assayed by competitive binding. Levels of messenger RNA for the C3a and C5a receptors were analyzed by reverse transcriptase-polymerase chain reaction. Changes of free cytosolic Ca(2+) concentration ([Ca(2+)]i) in response to C3a and C5a were measured. RESULTS: Basal MONO-MAC-6 cell sites for C3a and C5a binding were 10900 C3aR/cell (K(d)=2.0 nmol/L), 8700 C5aR/cell (K(d)=0.9 nmol/L). IL-1alpha increased sites for both C3a (61% increase; P <.01) and C5a (71% increase; P <.001). Levels of C3aR and C5aR messenger RNA also increased in IL-1alpha-stimulated cells. Receptors were coupled to functional responses, which were demonstrated by C3a- or C5a-induced [Ca(2+)]i increases. IL-1 receptor antagonist blocked the effects of IL-1alpha upregulation of anaphylatoxin receptors. CONCLUSION: These results suggest that there is an additional link between IL-1 and anaphylatoxins to amplify proinflammatory effects through monocytes and macrophages. Although C3a and C5a can increase the monocyte production of IL-1, IL-1 increases monocyte expression of receptors for these anaphylatoxins, which further amplifies inflammation.
    [Abstract] [Full Text] [Related] [New Search]