Molecular characterization reveals selective upregulation of the novel BL34 gene in activated B cells and leukemia, suggesting a distinct functional role in lymphocyte activation.
Key Points
To identify and characterize novel genes that are differentially expressed between human B and T lymphocytes during activation.
Isolated differentially expressed clones using subtractive cDNA cloning from B and T lymphocyte populations.
Analyzed BL34 transcript size and expression patterns via Northern blot across resting, mitogen-activated, and leukemic cells, alongside Southern blot genomic analysis.
Sequenced full-length cDNAs and mapped anatomical expression in human tonsil tissue sections using in situ hybridization.
Identified BL34 as a single-copy gene without rearrangement, possessing an open reading frame of 588 bp encoding a novel 196-amino acid protein.
Detected a 1.6-kb BL34 mRNA transcript that was upregulated in mitogen-activated B cells, PMA-treated B cell lines, and B-cell acute lymphocytic leukemia, but undetectable in activated T cells.
Localized BL34 mRNA expression in situ predominantly to cells within the germinal center and regions adjacent to the mantle zone of human tonsil tissue.