Differential in vitro modulation of suppressor and antitumor functions of mouse macrophages by lymphokines and/or endotoxin.
Peritoneal macrophages of normal mice exhibited natural suppressor activity, as indicated by their ability to inhibit the proliferation of spleen cells in response to stimulation with phytohemagglutinin (PHA) or concanavalin A (Con A). Their suppressor function could be modulated in vitro with a variety of treatment regimens. High-dose lipopolysaccharide (LPS) (LPSH; 10 micrograms/ml) or lymphokines (supernatant from Con A-stimulated spleen cells) plus low-dose LPS (LPSL; 10 ng/ml) caused a reduction in the suppressor activity of adherent peritoneal macrophages. In contrast, these same treatments induced the macrophages to become tumoricidal and cytostatic for tumor cells, indicating a major dissociation between the regulation of suppressor and cytotoxic activities of macrophages. The lack of correlation between these activities was further demonstrated by macrophages that had been activated in vitro by Corynebacterium parvum: these cells expressed high tumoricidal and cytostatic activities, and also strong suppressor activity. The suppressor function could be selectively downregulated by in vitro pretreatment with LPSH.
Chang
Z L
ZL
Laboratory of Molecular Immunoregulation, National Cancer Institute, Frederick, Maryland 21701.
Bonvini
E
E
Varesio
L
L
Holden
H T
HT
Herberman
R B
RB
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004731:Endotoxins / Q000494:pharmacology*; D005260:Female; D007940:Leukemia L5178 / Q000276:immunology* / Q000473:pathology; D007942:Leukemia, Experimental / Q000276:immunology*; D008222:Lymphokines / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013481:Superoxides / Q000096:biosynthesis
D000276:Adjuvants, Immunologic; D004731:Endotoxins; D008222:Lymphokines; D013481:Superoxides