Activation of mouse macrophages by in vivo and in vitro treatment with a cyanine dye, lumin.
The cyanine photosensitizer, lumin, is a potent macrophage activating agent: 4 days after administration of small amounts of lumin to mice (20-40 ng mouse-1), peritoneal macrophages exhibited a greatly enhanced Fc-mediated ingestion activity; higher doses (more than 3000 ng mouse-1) did not have this effect. The in vitro photodynamic activation of macrophages in mouse peritoneal cells exposed to white fluorescent light (3 J m-2 s-1) was also studied in media containing various concentrations of lumin. A short light exposure (45 J m-2) with 10 ng lumin ml-1 produced a maximum ingestion activity of macrophages. Lumin has absorption peaks at 670 and 760 nm. Therefore we designed experiments in which peritoneal cells were exposed to a red fluorescent light (emission, 660 nm; 0.5 J m-2 s-1). In a medium containing 3 ng lumin ml-1 with 7.5 J m-2 of red light, a markedly enhanced ingestion activity of macrophages was observed. The photodynamic treatment of peritoneal macrophages alone did not stimulate phagocytic activity, but the photodynamic treatment of a mixture of non-adherent (B and T) cells and macrophages resulted in a greatly enhanced ingestion activity of macrophages. Thus non-adherent cells are required for the photodynamic activation of macrophages, implying that an activating factor is generated within the non-adherent cells and transmitted to the macrophages. This hypothesis was confirmed by the observation that co-cultivation of photodynamically treated non-adherent cells with untreated macrophages resulted in a greatly enhanced ingestion capacity.
Yamamoto
N
N
Department of Biochemistry, Temple University School of Medicine, Philadelphia, PA 19140.
Homma
S
S
Nakagawa
Y
Y
Hayami
M
M
Imanaga
H
H
Kurimoto
M
M
Mitsuhashi
M
M
Kimoto
T
T
D000818:Animals; D005260:Female; D005453:Fluorescence; D008027:Light; D008262:Macrophage Activation / Q000187:drug effects* / Q000528:radiation effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D010529:Peritoneal Cavity / Q000166:cytology; D010587:Phagocytosis / Q000187:drug effects / Q000528:radiation effects; D011806:Quinolinium Compounds / Q000494:pharmacology*
D011806:Quinolinium Compounds; C052194:lumin