title: Release of immunosuppressive factor(s) by MOPC-315 murine plasmacytoma cells: a possible mechanism of defence.
abstract: Supernatants were collected from suspensions of MOPC-315 tumor cells harvested from ascitic tumors and kept for 24 hours in culture medium and from cultures of an MOPC-315 tumor-cell kept for a long period of time in vitro. The MOPC-315 supernatants were tested for immunosuppression of mitogenic stimulation of BALB/c spleen cells by ConA or LPS, of allogeneic response of effector BALB/c spleen cells against target C57BL spleen cells, of generation of antibody response against SRBC and of induction of LAK activity. The immunosuppression was marked in all the test systems, was not related to secretion of either C-type particles or of anti-TNP antibodies and was also induced by MOPC-315 tumor cells kept in serum-free medium. It is suggested that release of immunosuppressive factor(s) by MOPC-315 tumor cells might play a role in the mechanism(s) of defence of the tumor against the host.
authors.affiliation: Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Bomstein
authors.forename: R
authors.initials: R
authors.lastname: Ophir
authors.forename: H
authors.initials: H
authors.lastname: Harshemes
authors.forename: S
authors.initials: S
authors.lastname: Ben-Efraim
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D003470:Culture Media; D007155:Immunologic Factors / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010954:Plasmacytoma / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D003470:Culture Media; D007155:Immunologic Factors; D007166:Immunosuppressive Agents