Premium
Activation of Rat Alveolar Macrophages by Gamma Interferon to Inhibit Toxoplasma gondii In Vitro
Author(s) -
Badger Alison M.,
Hutchman John S.,
Sung ChengPo,
Bugelski Peter J.
Publication year - 1987
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.42.5.447
Subject(s) - toxoplasma gondii , biology , phagocytosis , in vitro , microbiology and biotechnology , incubation , interferon , intracellular , interferon gamma , lipopolysaccharide , intracellular parasite , pulmonary alveolus , macrophage , immunology , biochemistry , antibody
We have investigated the effects of murine interferons on the ability of rat alveolar macrophages (AM) to inhibit the proliferation of the intracellular protozoan Toxoplasma gondii. This activity was determined by measuring suppression of 3 H‐uracil uptake into the Toxoplasma and by microscopic enumeration of the intracellular organisms. Recombinant gamma interferon (rMuIFN‐γ), but not alpha/beta interferon (IFN‐α/β) was able to activate AM for antimicrobial activity in vitro. Maximum activation was achieved by incubation with 50‐200 units/ml rMuIFN‐γ and the activity was lost at one unit/ml. The highest levels of activation were obtained when macrophages were incubated with interferon for 48‐72 h prior to the challenge with Toxoplasma organisms. Activation could still be obtained, however, when the interferon was added to the cultures as late as 2 h after the phagocytosis of Toxoplasma. Neither MDP nor low concentrations (1‐1‐ng/ml) of S. typhosa lipopolysaccharide (LPS) were able to activate these cells to inhibit the growth of Toxoplasma. Phagocytosis of Toxoplasma by AM did not result in the release of O 2 − , in fact the spontaneous release of O 2 − by these cells was inhibited by Toxoplasma. This inhibition was reversed by preincubation of the cells with rMuIFN‐γ.