In vitro modulation of macrophage tumoricidal activity - Enhanced tumor cell killing by sodium periodate-treated peritoneal macrophages or sodium periodate-treated cloned macrophages

NaIO4 treatment of mouse adherent peritoneal cells or lymphocyte-free cloned macrophages enhances their cytotoxic and tumoricidal activity. 5×10^-3 M NaIO4 treatment of nontumoricidal BCG-activated macrophages renders them completely tumoricidal, whereas the same treatment of stimulated (peptone-normal) macrophages renders them weakly tumoricidal. Addition of LPS in nanogram quantities too low to enhance tumor cell killing by untreated peptone-normal macrophages causes NaIO4-treated peptone-normal macrophages to be maximally tumoricidal. The activating action of NaIO4, MAF, or LPS can be potently, but inconsistently, blocked or reversed by the reducing agent NaBH4 or the aldehyde-reacting agent dimedone. NaIO4 treatment of lymphocyte-free macrophage colonies does not make them cytotoxic, but NaIO4-treated colony macrophages are cytotoxic for tumor cells when cultured in 10 ng/ml LPS (an amount of LPS inadequate to render untreated colony macrophages cytotoxic). Supernatants of NaIO4-treated adherent peritoneal cells contain MAF activity. Thus, the NaIO4-induced enhancement of peritoneal cell tumoricidal activity may result from both direct NaIO4 activating effects on macrophages and indirect NaIO4 effects through NaIO4-induced MAF production. © 1980 Springer-Verlag.

Duke Scholars

Author Joe Brice Weinberg Medicine, Hematology