Lunger, J. C.; Sant'Anna, L. E.; Salcido-Alcantar, A.; Arroyo Hornero, R.; Cho, W.; Vaughan-Jackson, A.; Gu, M.; Liu, J. Y.; Beckett, A. N.; Parrilla-Garcia, J.; Ramakrishna, S.; Bassik, M. C.; Daniels, K. G.

Technology that precisely controls macrophage polarization to distinct functional states would deepen our understanding of macrophage biology and enable development of new macrophage cell therapies. Here, we use a synthetic cytokine receptor (SCR) platform with programmable signaling domains to control primary human macrophage polarization. SCRs containing signaling motifs from the interferon-gamma (IFN-{gamma}) or Interleukin-10 (IL-10) receptors mimic key features of pro-inflammatory or anti-inflammatory polarization, respectively. Random recombination of nine distinct signaling motifs to create new SCR signaling domain generates a diverse landscape of synthetic macrophage states with varied expression of inflammatory markers (CD80, CD40) and anti-inflammatory markers (CD163, CD206), and varied phagocytic capacity. SCRs programmed with multiple YLxQ motifs increase macrophage phagocytosis of E. coli and chimeric antigen receptor (CAR)-macrophage phagocytosis of cancer cells in mice, reducing tumor burden by 30-fold. The motif-dependent polarization is well-described by a two-state model, enabling quantitative prediction of macrophage polarization state from SCR signaling domain composition. Leveraging this model, we design an SCR that simultaneously enhances phagocytosis and maintains a macrophage pro-inflammatory state. Together, these findings establish a framework to synthetically program macrophage polarization states with potential applications in cancer immunotherapy and other disease contexts.