title: Low molecular weight factors displaying augmenting activity for human antibody production in vitro.
abstract: Dialyzable low molecular weight antibody-augmenting factors (LMAAF) were found in the culture supernatant of human tonsillar lymphocytes which were not stimulated by antigen and/or mitogen in vitro. Phagocyte-depleted nylon wool-adherent lymphocytes (M-Ny+ cells) were responsible for the release of the LMAAF. Marbrook's culture system was adopted to assay for the LMAAF. The M-Ny+ cells, which were cultured without antigen and/or without mitogen in the reservoir of Marbrook's diffusion culture vessel, released the LMAAF, which diffused across a dialysis membrane and significantly augmented the pokeweed mitogen (PWM)-induced plaque-forming cell (PFC) response of phagocyte-depleted lymphocytes (M-cells) cultured in the inner vessel. Phagocyte-depleted nylon wool-passed lymphocytes (M-Ny- cells) cultured in the reservoir could not augment the PWM-induced PFC response of the M- cells cultured in the inner vessel. The exuded fluid, which was the dialysate of the culture supernatant of the M-Ny+ cells ultrafiltrated with dialysis tubing, also enhanced the PFC response of M- cells cultured in 24-well multi plates. The exuded fluid also augmented the total IgM and IgG production of human tonsillar and peripheral blood lymphocytes measured by enzyme-linked immunosorbent assay (ELISA) systems. Gel filtration chromatography on Sephadex G-25 Superfine column showed that the LMAAF activity was demonstrated in the fractions corresponding to a molecular weight (m.w.) of 362 to 1,355 and a m.w. of 3,560 to 5,700, with a peak activity at about 4,500 dalton. The LMAAF were inactivated by treatment with proteinase K, but not by trypsin, alpha-chymotrypsin, RNase, and DNase, and were stable when treated at 56 C for 60 min. The dialysates of culture supernatants from two out of seven Epstein-Barr virus (EBV)-transformed M-Ny+ cell lines showed LMAAF-like activity. These results indicate that phagocyte-depleted nylon wool-adherent lymphocytes, possibly B cells, release low molecular weight factors displaying augmenting activity for human antibody production in vitro.
authors.affiliation: Department of Microbiology and Immunology, Hamamatsu University School of Medicine, Shizuoka.
authors.forename: S
authors.initials: S
authors.lastname: Haraguchi
authors.forename: T
authors.initials: T
authors.lastname: Hongo
authors.forename: H
authors.initials: H
authors.lastname: Ishihara
authors.forename: T
authors.initials: T
authors.lastname: Matsuo
authors.forename: T O
authors.initials: TO
authors.lastname: Yoshida
mesh_terms: D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000187:drug effects* / Q000276:immunology; D002461:Cell Line, Transformed / Q000378:metabolism; D019286:Endopeptidase K; D004854:Herpesvirus 4, Human; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D008222:Lymphokines / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D007074:Immunoglobulin G; D008222:Lymphokines; D012697:Serine Endopeptidases; D019286:Endopeptidase K