Characterization of long-term cultured bovine CD4-positive and CD8-positive T-cell lines and clones.
Long-term cultured CD4+ or CD8+ bovine T-cell lines and clones were established. The CD8+ T-cell line and clones had a strong lectin-dependent cytotoxicity, whereas the CD4+ T-cell line did not. Both phenotype cell lines grew in an interleukin-2 (IL-2)-dependent manner and expressed 50,000-55,000 MW and 65,000-75,000 MW proteins associated with a putative IL-2 receptor (IL-2R), as demonstrated by the cross-linking of radioiodinated recombinant human IL-2 (rhIL-2). Additional molecules of 13,000 and 27,000 MW were also observed on CD8+ T cells. The binding of rhIL-2 was blocked by crude bovine IL-2, and Scatchard plot analysis of the binding data showed that both phenotype cells expressed two different affinity IL-2R that had equilibrium dissociation constants of 12-20 pm (3000-6000 sites/cell) and 146-490 pM (16,000-25,000 sites/well). Only IL-2 stimulated DNA synthesis in these cell lines, whereas mitochondrial enzymes activity, protein synthesis and protein secretion were enhanced by IL-2, mitogens and phorbol myristate acetate. The supernatant from mitogen-stimulated CD4+ cells was unable to enhance the DNA synthesis of either the CD4+ or CD8+ lines, whereas both freshly prepared Con A blasts and anti-immunoglobulin-treated bovine B cells showed elevated DNA synthesis under the same conditions.
Takamatsu
H
H
Division of Immunology, Pirbright Laboratory, AFRC Institute for Animal Health, Pirbright, Surrey, U.K.
Collen
T
T
Tucker
D L
DL
Denyer
M S
MS
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D016827:CD8 Antigens; D002417:Cattle; D002460:Cell Line; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation; D011994:Recombinant Proteins / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors
D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D007376:Interleukin-2; D011994:Recombinant Proteins