title: Infection with the intracellular protozoan parasite Theileria parva induces constitutively high levels of NF-kappa B in bovine T lymphocytes.
abstract: The intracellular protozoan parasite Theileria parva causes a lymphoproliferative disease of T cells in cattle and uncontrolled lymphocyte proliferation in culture. We have identified and characterized in infected cells the transcriptional activator, NF-kappa B, whose recognition motifs have been identified in several gene enhancers important for lymphocyte-specific gene expression. NF-kappa B is normally constitutively activated in nuclear extracts derived from B cells and can be induced in T cells and nonlymphoid cells by phorbol esters. Theileria-infected lymphocytes contained constitutively high levels of activated NF-kappa B in nuclear fractions and inactive NF-kappa B in cytoplasmic fractions. The inactive cytoplasmic precursor could be activated by treatment of extracts with deoxycholate, which was shown previously to dissociate NF-kappa B from an inhibitor, I kappa B. Treatment of lymphocyte extracts with 3 mM GTP stimulated NF-kappa B binding to its recognition motif in vitro, thereby distinguishing it from a related nuclear factor, H2-TF1. Selective killing of the parasite, which left the host cells intact, resulted in a rapid loss of NF-kappa B from the nuclear fractions and a slower loss from the cytoplasmic fractions. In parasitized cells, NF-kappa B could not be further stimulated by treatment with 12-O-tetradecanoylphorbol-13-acetate whereas in cells treated to remove the parasite, this compound stimulated elevated levels of NF-kappa B. We propose that high levels of activated NF-kappa B are maintained by the presence of the parasite in infected T cells. Similarly, we propose that the high levels of inactive cytoplasmic precursor are a result of increased synthesis due to the presence of the parasite.
authors.affiliation: Kernforschungszentrum, Institut für Genetik und Toxikologie, Karlsruhe, Federal Republic of Germany.
authors.forename: V
authors.initials: V
authors.lastname: Ivanov
authors.forename: B
authors.initials: B
authors.lastname: Stein
authors.forename: I
authors.initials: I
authors.lastname: Baumann
authors.forename: D A
authors.initials: DA
authors.lastname: Dobbelaere
authors.forename: P
authors.initials: P
authors.lastname: Herrlich
authors.forename: R O
authors.initials: RO
authors.lastname: Williams
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000502:physiology*; D002417:Cattle; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003593:Cytoplasm / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004742:Enhancer Elements, Genetic; D006160:Guanosine Triphosphate / Q000494:pharmacology; D015497:HIV-1 / Q000235:genetics; D016328:NF-kappa B; D010957:Plasmids; D013601:T-Lymphocytes / Q000378:metabolism / Q000469:parasitology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013801:Theileriasis / Q000469:parasitology; D014157:Transcription Factors / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D016328:NF-kappa B; D014157:Transcription Factors; D006160:Guanosine Triphosphate; D015500:Chloramphenicol O-Acetyltransferase; D013755:Tetradecanoylphorbol Acetate