To investigate how different adjuvants influence macrophage activation induced by freeze–thaw whole-cell lysates prepared from two breast cancer cell lines (MCF-7 and MDA-MB-231), we evaluated the effects of alum and saponin in J774 macrophages by assessing cell viability, nitric oxide (NO) production, and cytokine responses. Freeze–thaw breast cancer antigens (FTBA) triggered macrophage responses in a dose-dependent manner, with 40 µg/mL providing a suitable balance between activation and viability. When combined with adjuvants, FTBA + alum maintained higher macrophage viability compared with FTBA + saponin. Alum-adjuvanted FTBA induced stronger NO production than saponin-adjuvanted formulations. Cytokine profiling showed that alum-adjuvanted FTBA induced the strongest cytokine responses overall, with fold-increases in IL-6, IL-12, TNF-α, and GM-CSF observed for both antigen sources. Overall, alum enhanced macrophage activation with lower cytotoxicity than saponin, indicating that adjuvant selection significantly modulates innate immune responses to freeze–thaw tumor antigens.
Ihlamur et al. (Sun,) studied this question.