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Some Physicochemical Characteristics of an Immune Lymphocyte Product Which Inhibits the Multiplication of Toxoplasma within Mouse Macrophages
Author(s) -
Shirahata Toshikazu,
Shimizu Kiheiji
Publication year - 1979
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1979.tb00436.x
Subject(s) - sephadex , isoelectric point , isoelectric focusing , biology , neuraminidase , microbiology and biotechnology , biochemistry , enzyme
In response to antigenic stimulation, the splenic lymphocytes from Toxoplasma‐infected mice produce a factor which is called by the authors the Toxoplasma growth inhibitory factor (Toxo‐GIF) and which inhibits the multiplication of Toxoplasma within nonimmune macrophages in vitro . In this study, partial characterization of murine Toxo‐GIF was examined using Sephadex G‐100 gel‐filtration, isoelectric focusing, zonal electrophoresis and heat and enzymatic treatment. Peak activity of Toxo‐GIF was found in a Sephadex G‐100 fraction with a similar molecular size to that of the ovalbumin. The molecular weight of Toxo‐GIF was calculated to be between 38,000 and 55,000. Toxo‐GIF was stable to heating at 56 C for 30 min but lost its activity at 80 C for 30 min or by exposure to pH values of 5 and 2. Exposure of Toxo‐GIF to water‐insoluble chymotrypsin or neuraminidase markedly decreased its ability to induce enhanced microbicidal activity of cultured macrophages, suggesting that Toxo‐GIF was a glycoprotein. Furthermore, Toxo‐GIF migrated in a region cathodal to mouse albumin on agar zone electrophoresis. Isoelectric focusing of active Sephadex fractions showed a well‐defined peak of Toxo‐GIF activity with an isoelectric point of pH 4.9 to 5.9.