title: Inhibitory effect of mycoplasma-released arginase. Activity in mixed-lymphocyte and tumour cell cultures.
abstract: Non-fermenting mycoplasma species deplete culture media for arginine through arginase activity linked to their arginine deiminase pathway, resulting in proliferation arrest and cell death in mycoplasma-contaminated cell cultures. The presence of only 2-3 Mycoplasma (M.) arginini-contaminated T cells in a one-way allogeneic mixed-lymphocyte culture (MLC) significantly inhibits development of cytotoxic T-cell activity. Likewise, strong degrees of inhibition are observed after addition of nanogram doses of M. arginini extracts (MAE) to MLC or cell proliferation cultures. M. arginini-induced cell inhibition can be reversed by addition of excess arginine to the culture medium. Antisera raised against non-fermenting, but not against fermenting, mycoplasma species block the inhibitory effect of MAE. SDS-PAGE separation of MAE disclosed a broad band at 60 kDa which contained arginase activity when assayed in MLC and cell proliferation culture. SDS-PAGE followed by western blotting and reaction with antisera raised against non-fermenting mycoplasma species demonstrated a band at 43 kDa common for these micro-organisms.
authors: Department of Medical Anatomy A. University of Copenhagen, Denmark.
authors: M H
authors: MH
authors: Claesson
authors: T
authors: T
authors: Tscherning
authors: M H
authors: MH
authors: Nissen
authors: K
authors: K
authors: Lind
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial; D001119:Arginase / Q000502:physiology*; D015153:Blotting, Western; D002455:Cell Division; D002460:Cell Line; D006131:Growth Inhibitors; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D009174:Mycoplasma / Q000201:enzymology*; D013601:T-Lymphocytes / Q000382:microbiology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology*; D014407:Tumor Cells, Cultured
chemical_list: D000907:Antibodies, Bacterial; D006131:Growth Inhibitors; D001119:Arginase