Characterization of a novel bovine leukocyte protein involved in cell-cell adhesion.

Preliminary characterization of an apparently novel bovine leukocyte adhesion protein is described. Two IgG1 monoclonal antibodies, UC-C1 and UC-H5, raised against established cultures of IL-2-dependent bovine peripheral blood lymphocytes (PBL) were found to react with an antigen expressed by the majority of bovine peripheral blood leukocytes. Immunoprecipitation and polyacrylamide gel electrophoresis of the antigen produced a distinct protein band of molecular weight 160,000, and additional diffuse protein bands of approximate molecular weight 180,000, 175,000, and 150,000.

Expression of HOX C homeobox genes in lymphoid cells.

The class I homeobox genes located in four clusters in mammalian genomes (HOX A, HOX B, HOX C, and HOX D) appear to play a major role in fetal development. Previous surveys of homeobox gene expression in human leukemic cell lines have shown that certain HOX A genes are expressed only in myeloid cell lines, whereas HOX B gene expression is largely restricted to cells with erythroid potential. We now report a survey of the expression patterns of 9 homeobox genes from the HOX C locus in a panel of 24 human and 7 murine leukemic cell lines.

Differential expression of bovine MHC class II antigens identified by monoclonal antibodies.

Four monoclonal antibodies (mAbs), UC-A4, UC-D3, UC-H9, and IL-A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin-labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL-A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UC-D3 and UC-H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins.

Factors affecting the in vitro evolution of a myeloma cell line.

A continuously growing plasma cell line has been established from the bone marrow of a multiple myeloma patient. Initial growth of the cells was dependent on the presence of bone marrow stromal cells. Following initial outgrowth the cells were maintained by transfer onto non-autocthonous bone marrow stromal cultures.

Development and characterization of a monoclonal antibody specific for the bovine low-affinity interleukin-2 receptor, BoCD25.

An IgM monoclonal antibody, UC-2C2 was produced using splenocytes from mice immunized with cultures of interleukin-2 (IL-2)-dependent bovine peripheral blood lymphocytes. UC-2C2 was found to recognize a cell surface antigen of apparent molecular weight 52,000-54,000 present on activated bovine peripheral blood mononuclear leucocytes (PBML) but not on resting PBML or cells of the bovine lymphoblastoid cell line BL3. The 52,000-54,000 MW antigen was expressed early following activation of PBML by mitogens or alloantigens, with the majority of cells positive by 48 h of culture.