Production of an interleukin-1 inhibitor by cell line P388D1 murine macrophages stimulated with Haemophilus actinomycetemcomitans lipopolysaccharide.
Murine macrophages of the P388D1 cell line stimulated with lipopolysaccharide (LPS) from Haemophilus actinomycetemcomitans Y4 released an interleukin-1 (IL-1) inhibitor, as well as IL-1. Maximal IL-1 activity in culture supernatants was detected after 24 h of culture. On the other hand, IL-1 inhibitor activity reached a maximum level after 72 h of culture. An IL-1 inhibitor was partially purified from the culture supernatant of P388D1 cells stimulated with Y4 LPS for 72 h by ammonium sulfate precipitation, followed by Sephacryl S-200 gel chromatography. A 160-kilodalton peak inhibitory to IL-1 and a 14-kilodalton peak showing IL-1 activity were separated by Sephacryl S-200 column chromatography. The partially purified IL-1 inhibitor significantly suppressed the proliferation of C3H/HeJ murine thymocytes that had been induced with murine and human IL-1 in the presence of a submitogenic dose of concanavalin A. The IL-1 inhibitor more strongly suppressed human recombinant IL-1 beta than human recombinant IL-1 alpha. This inhibitory activity of the partially purified preparation was unaffected by the presence of trypsin inhibitor and the protease inhibitor aprotinin. The IL-1 inhibitor did not exhibit either IL-2 or IL-2 inhibitor activity. The inhibitor suppressed C3H/HeJ thymocyte proliferation induced by IL-1 in the presence of a saturated concentration of IL-2 instead of a suboptimal concentration of concanavalin A. These results indicate that prolonged culture of Y4 LPS-stimulated murine macrophages releases a specific inhibitor of IL-1.
Nishihara
T
T
Department of Dental Research, National Institute of Health, Tokyo, Japan.
Koga
T
T
Hamada
S
S
D000818:Animals; D002460:Cell Line; D006190:Haemophilus / Q000276:immunology*; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008222:Lymphokines / Q000032:analysis* / Q000494:pharmacology; D008262:Macrophage Activation; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D011480:Protease Inhibitors / Q000494:pharmacology; D013997:Time Factors
D007375:Interleukin-1; D008222:Lymphokines; D011480:Protease Inhibitors