Mitomycin C-augmented production of I-A antigen-positive macrophages in tumor vaccine-primed mice.
Intraperitoneal inoculation of L1210 murine leukemia cell vaccine increased I-Ad antigen-positive and -negative macrophages in the peritoneal cavity of histocompatible mice. Mitomycin C, a poor producer of I-Ad antigen-positive macrophages, selectively augmented the production of I-Ad antigen-positive macrophages in L1210 vaccine-primed mice, since it did not augment the production of non-macrophage cells. Since our previous study showed that the priming of mice with L1210 vaccine and mitomycin C induced augmented antitumor response, we tested the feasibility of the association of mitomycin C-augmented I-Ad antigen-positive macrophages with the augmented antitumor response. Prostaglandin E2 suppressed the antitumor response in L1210 vaccine- and mitomycin C-primed mice and, consistent with this, it inhibited the production of I-Ad antigen-positive macrophages, although it inhibited the production of non-macrophage cells as well. This hypothesis was further tested by the use of silica. When L1210 vaccine- and mitomycin C-primed mice were further given silica on the day of and one day after live L1210 inoculation, their antitumor response was strongly suppressed, while a kinetic analysis of the cellularity of peritoneal cells showed that administration of silica resulted in a decrease of I-Ad antigen-positive macrophages, but not I-Ad antigen-negative macrophages or non-macrophage cells in these mice. These results strongly suggest, though they do not prove, the association of mitomycin C-augmented production of I-Ad antigen-positive macrophages with the antitumor response in L1210 vaccine- and mitomycin C-primed mice.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology*; D015232:Dinoprostone; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007939:Leukemia L1210 / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D012822:Silicon Dioxide / Q000494:pharmacology; D014612:Vaccines / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D008937:Mitomycins; D011458:Prostaglandins E; D014612:Vaccines; D016685:Mitomycin; D012822:Silicon Dioxide; D015232:Dinoprostone