SPERMINE ENHANCES IGM PRODUCTIVITY OF HUMAN-HUMAN HYBRIDOMA HB4C5 CELLS AND HUMAN PERIPHERAL-BLOOD LYMPHOCYTES

The polyamine spermine was assessed for enhancement of IgM production by human-human hybridoma, HB4C5 cells, under serum-free conditions. Ig M production of HB4C5 cells was stimulated approximately 6-fold by the addition of 7.3 mM of spermine. The facilitating effect was observed soon after inoculation. In spite of suppression of cell growth, the Ig M production rate was accelerated for at least 5 days without medium c hange. Moreover, laser confocal microscopic analysis revealed that the IgM content inside HB4C5 cells was increased by spermine treatment. T hese findings suggest that spermine enhances specific IgM productivity of the hybridoma line. Spermine also facilitated IgM production by hu man peripheral blood lymphocytes under serum-free conditions. This res ult implies that spermine enhances immunoglobulin production of not on ly specific hybridoma lines, but also nonspecific immunoglobulin produ cers. Immunoglobulin production stimulating activity of spermine was a ccelerated 2-fold by the addition of DNA whith a chain length of about 400-7000 base pairs (bp). However, degraded short-chain DNA fragments (less than 200 bp) did not facilitate the immunoglobulin production s timulating activity of spermine.