ABSTRACT
We report the cloning of an ovine c-myc cDNA. The clone was isolated from a bovine leukemia virus-infected cell line (YR2) cDNA library cloned in the lambda gt10 vector. The clone encodes the full length c-Myc protein made of 439 amino-acids with 93, 96, 92 and 93% similarity with human, feline, murine and rat c-Myc proteins, respectively.
Subject(s)
Genes, myc , Amino Acid Sequence , Animals , Base Sequence , Cats , Cloning, Molecular , Humans , Leukemia Virus, Bovine/genetics , Molecular Sequence Data , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Rats , Sequence Analysis, DNA , Sequence Homology, Amino Acid , SheepABSTRACT
Peripheral blood mononuclear cells (PBMCs) from bovine leukaemia virus (BLV)-seronegative cattle and from BLV-seropositive cows either with normal haematological values or persistent lymphocytosis were tested for their proliferative response to BLV antigens. Cells from only BLV-infected cattle with normal lymphocyte counts were stimulated to a detectable level by the fetal lamb kidney cell supernatant containing BLV antigens. Proliferation assays performed with the purified major core protein p24 indicated that this protein has to be processed through a chloroquine-sensitive compartment before being recognized by CD4+ T lymphocytes. Forty-one 15-mer overlapping peptides spanning the entire p24 sequence were synthesized and analysed for their stimulating potential. It appeared that two regions included T cell epitopes recognized by PBMCs from three of five animals tested. These regions were represented by amino acids 31 to 55 (PGSQVWIQTLRLAILQADPTPADLE) and 141 to 165 (AESYVEFVNRLQISLADNLPDGVPK). The possible implication of this cell-mediated immune response in BLV pathogenesis and vaccine development is discussed.
