ABSTRACT
Amyloidosis is caused by an amyloidogenic immunoglobulin light chain secreted by a clonal plasma cell. The full length rearranged λ6 light chain gene including variable and constant domains was amplified from cDNA prepared from bone marrow RNA from a patient with aggressive multiorgan amyloidosis. This amplicon was cloned into a variety of different expression vectors to test the efficiency of the promoter and enhancer construct by transient and stable in vitro transfection. The tumors secrete the human λ6 light chain in vivo and it is detected in the circulation by Western blot. The β-actin promoter construct expressed high levels of λ6 protein assessed by Western blotting in cross-over spacing cells, but not in SP2/0 or 3T3 cells.
