title: Inhibition of [3H]thymidine incorporation by Mycoplasma arginini-infected cells due to enzymatic cleavage of the nucleoside.
abstract: Culture supernatants contaminated by Mycoplasma arginini inhibit the incorporation of [3H]thymidine ([3H]dThd) by cytotoxic T lymphocyte cell lines. This study presents evidence that the inhibition of uptake of the nucleoside is due to the rapid cleavage of the exogenous [3H]dThd into thymine. Uridine and cytidine as well as dThd are degraded by the mycoplasma-contaminated supernatants, while no cleavage was observed with uninfected supernatants. Cells contaminated by mycoplasma apparently release a pyrimidine-specific nucleosidase, possibly a dThd phosphorylase, which is responsible for the inhibition.
mesh_terms: D002460:Cell Line; D006801:Humans; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation; D009174:Mycoplasma / Q000502:physiology*; D009699:N-Glycosyl Hydrolases / Q000096:biosynthesis / Q000502:physiology; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism*
chemical_list: D009699:N-Glycosyl Hydrolases; D013936:Thymidine