Purification and characterization of immunoglobulin production stimulating factor derived from human B lymphoblastoid HO-323 cells

Abstract

An immunoglobulin (Ig) production stimulating factor (IPSF) for hybridomas was found in spent medium of the human B lymphoblastoid cell line, HO-323. The IPSF was purified by serial use of DEAE chromatography, ultrafiltration, gel filtration and HPLC-DEAE chromatography. Purified IPSF was estimated to be a 410 k macro molecule by gel filtration, and contained three types of isomers which were separated from each other by native polyacrylamide gel electrophoresis. All of the isomers were, however, assumed to have the same protein components by SDS polyacrylamide gel electrophoresis. The IPSF was effective for human-human and mouse-mouse hybridomas producing IgM, but not for IgG producers in the experimental condition used here. Human-human hybridoma HF10B4, cultured in IPSF-containing medium, produced 20 times more IgM than in IPSF-free medium under serum-free conditions. The IPSF showed very little proliferation stimulating activity on HF10B4 cells.

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“…Several methods of enhanced productivity of monoclonal antibody, which was achieved by increasing the cell concentration and/or the specific productivity of monoclonal antibody, were investigated by sev-eral researchers (Lee et al, 1994;Yamaguchi et al, 1997;Takahashi et al, 1994;Murakami et al, 1997). Productivity often depends on the components of culture media containing autocrine factors (Toyoda et al, 1990;Sugahara et al, 1991), extracts from plants and cells (Kim et al, 1993), and other components (Mochizuki et al, 1993).…”

The mode of actions of glyceraldehyde‐3‐phosphate dehydrogenase identified as an immunoglobulin production stimulating factor

“…Several factors termed immunoglobulin production stimulating factor (IPSF) were discovered in cell extracts or culture medium. IPSF-I was discovered in culture medium from a human lymphoblastoid cell line HO-323 [1], and IPSF-II was purified from cell lysate of human Burkitt's lymphoma, Namalwa cells [2,3]. The previous data revealed that the Namalwa cell lysate contained two IPSF active substances, IPSF-Ikx and -II,8, respectively.…”

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“…We have demonstrated that there are substances termed Ig production stimulating factor (IPSF) which enhance Ig production by hybridomas and lymphocytes. IPSF-I purified from culture medium of human lymphoblastoid cell line, HO-323 was a 410 kDa macro-protein (Toyoda et al, 1990). IPSF-II was found in cell extracts of Namal-wa cells (Sugahara et al, 1991a).…”