PU.1 expression in Hodgkin cell lines and transient cotransfections of the Hodgkin cell lines L428 and KM-H2 with immunoglobulin enhancer constructs.

(A) Western blot analysis of cell lysate proteins from Hodgkin (lanes 1-6), non-Hodgkin (Burkitt lymphoma: Daudi, Namalwa; pre-B cell line: Reh; lanes 7-9) cell lines and mature CD19⁺ B cells (B cells; lane 10), showing bands of PU.1 and Spi-B. Left margin, size markers in kilodalton. L428 (B) and KM-H2 (C) cells were transfected with luciferase reporter plasmids driven by conalbumin promoter with or without the MluI-HpaI fragment of the human IgH gene intronic enhancer (pEcona and pcona). Expression vectors for PU.1, Oct2, and BOB/OBF.1 were cotransfected as indicated. Relative luciferase activity is shown and transfections with empty expression vectors were arbitrarily set to 1.