ANTIBODY-MEDIATED ENHANCEMENT OF LEGIONELLA-PNEUMOPHILA-INDUCED INTERLEUKIN-1 ACTIVITY

The ability of antibody specific for Legionella pneumophila to enhance the induction of interleukin 1 (IL-1) production by murine peritoneal , splenic, and pulmonary macrophages in response to the bacterium was examined. Two preparations of L. pneumophila were utilized, a formalin -killed whole-cell preparation and viable bacteria. We measured both s ecreted (sIL-1) and cell membrane-associated (mIL-1) activities after incubation of the macrophages with the bacterial preparations in the p resence or absence of the antibody. Both bacterial preparations induce d sIL-1 and mIL-1 activities in each of the macrophage populations tes ted. These activities were generally enhanced by pretreating the bacte ria with antibody, with the greatest enhancing activity observed for t he formalin-killed preparations at lower doses of bacteria.