title: The proliferation-associated nuclear protein Ki-67 in the bovine system: partial characterisation and its application for determination of the proliferation of Theileria-infected bovine cells.
abstract: Theileria annulata-infected bovine cells as well as mitogen-stimulated bovine peripheral blood mononuclear cells (PBMC) express a proliferation-associated nuclear protein equivalent to the human Ki-67 protein. In analogy to the human system, the expression of the bovine Ki-67 protein is restricted to proliferating cells only, since (a) Ki-67 expression paralleled [3H]-thymidine incorporation in concanavalin A (Con A)-stimulated bovine PBMC, (b) Ki-67 was not detectable in quiescent bovine cells, and (c) Ki-67 expression in Theileria-infected cells is related to the presence of the parasites within the cytoplasm of the host cells; upon treatment with the theilericidal drug buparvaquone the parasites are destroyed and the cells cease to proliferate and to express the Ki-67 protein. Western-blot analysis of lysates of proliferating bovine cells revealed that the prototype monoclonal antibody Ki-67 and the new equivalent antibody MIB-1 detected one prominent protein band with an apparent molecular weight of 430 kDa. Two cDNA clones (pUC18.B1.Ki-67 and pUC18.B2.Ki-67) were isolated from a lambdagt11 cDNA library of T. annulata-infected bovine cells by immunoscreening with the monoclonal antibody MIB-1. Comparison of these cDNA sequences with those of the human Ki-67 protein revealed 60-70% identity. Within the "Ki-67 motif", identity proved to be 80% at the amino acid level. The remarkable identity between bovine and human Ki-67 proteins suggests that MIB-1 can be used as a marker for cell proliferation in animal research. In this context we could identify proliferating cells in lymph nodes of Theileria-infected animals and, furthermore, we could distinguish between infected and uninfected proliferating cells using MIB-1 and an antiserum against a recombinant parasite protein designated SA288.
authors.affiliation: Forschungszentrum Borstel, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Shayan
authors.forename: C
authors.initials: C
authors.lastname: Gerlach
authors.forename: F U
authors.initials: FU
authors.lastname: Hügel
authors.forename: G
authors.initials: G
authors.lastname: Kay
authors.forename: J D
authors.initials: JD
authors.lastname: Campbell
authors.forename: J
authors.initials: J
authors.lastname: Gerdes
authors.forename: J S
authors.initials: JS
authors.lastname: Ahmed
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002455:Cell Division; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000469:parasitology; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D017386:Sequence Homology, Amino Acid; D016796:Theileria annulata / Q000502:physiology*
chemical_list: D018076:DNA, Complementary; D019394:Ki-67 Antigen