Establishment of a bovine adenovirus type 3 (BAV3)-transformed hamster cell line and characterization of BAV3-tumor associated surface antigens.

Abstract

ABSTRACT. A clonal cell line of transformant, BHKT73, was isolated from BHK21/13 cells infected with bovine adenovirus type 3 (BAV3). BHKT73 cells showed characteristics typical of transformed cells, including the ability to grow in 1.3 % methylcellulose, high agglutinability with lectins, and unclear cytoplasmic microtubular fibers. Cot analysis showed that BHKT73 cells were contain BAV3 DNA.Tumor-associated surface antigens (TASAs) of BHKT73 cells, and TrD-5 and TrJE-6 cells (A31 cells transformed by BAV3 DNA fragments with respective map units of 3.6-19.7 and 0-11.9) were studied by the protein A binding assay with rabbit anti-BHKT73 IgG, BALB/c mice anti-BHKT73 antiserum and BALB/c mice anti-TrD-5 and TrJE-6 antisera. All these antisera bound to the surfaces of BHKT73, TrD-5 and TrJE-6 cells, but not to the surfaces of SV40-and murine sarcoma virus-transformed A31 cells. They also bound to the surface of polyomavirus-transformed cells (pyBHK and PV-4). After absorption with pyBHK cells, these antisera showed decreased ability to bind to the surfaces of BHKT73, TrD-5, PV-4 and pyBHK cells. These results indicate that all the genetic information of BAV3 that is required for the expression of BAV3-TASAs is included between the map units of 3.6 and 11.9 on the BAV3 gene, and that BAV3-TASAs may have antigenic determinant site(s) common to one of the TASAs on polyomavirus-transformed cells.Transformed cells have characteristics that differ from those of their normal counterparts. These characteristics include 1) alteration of morphology ; 2) change in cytoskeletal system, including the decrease of cytoplasmic microtubular fibers and the disappearance of actin cables or stress fibers (3,8,17,33); 3) increase in the degree of agglutination with lectins (6, 21, 29) ; 4) release of a plasminogen activator (31, 39); 5) loss of anchorage-dependent growth control ; 6) increase in the nutrient uptake (13); 7) blockage of glycolipid synthesis (12); 8) decrease of large external transformation-sensitive protein (LETS protein) (16) [also called cell surface protein (CSP) Abbreviations used: BAV3, bovine adenovirus type 3; TASAs, tumor-associated surface antigens; MuSV, murine sarcoma virus; MEM, minimum essential medium; FBS, fetal bovine serum; Con A, concanavalin A; WGA, wheat germ agglutinin; RCA, caster bean agglutinin; WFA, Wistaria floribunda agglutinin ; PBS, phosphate-buffered saline; HEPES, N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid; DOC, sodium desoxycholate; NP-40, nonidet P-40; SDS, sodium dodecyl sulfate. 121