Stimulus-Response signaling dynamics characterize macrophage polarization states

Macrophages show remarkable functional pleiotropy that is dependent on microenvironmental context. Prior studies have characterized how polarizing cytokines alter the transcriptomic and epigenetic landscape. Here we characterized the immune-threat appropriate responses of polarized macrophages by measuring the single-cell signaling dynamics of transcription factor NF{kappa}B. Leveraging a fluorescent protein reporter mouse, primary macrophages were polarized into 6 states and stimulated with 8 different stimuli resulting in a vast dataset. Linear Discriminant Analysis revealed how NF{kappa}B signaling codons compose the immune threat level of stimuli, placing polarization states along a linear continuum between the M1/M2 dichotomy. Machine learning classification revealed losses of stimulus distinguishability with polarization, which reflect a switch from sentinel to more canalized effector functions. However, the stimulus-response dynamics and discrimination patterns did not fit the M1/M2 continuum. Instead, our analysis suggests macrophage functional niches within a multi-dimensional polarization landscape. HighlightsO_LIPolarization of macrophages affects stimulus-response NF{kappa}B dynamics C_LIO_LIFor each condition, NF{kappa}B signaling codons quantify the "immune threat" level C_LIO_LIMachine Learning reveals polarization-induced canalization of stimulus-responses C_LIO_LINF{kappa}B stimulus-responses may define a landscape of macrophage states C_LI eTOC blurbMacrophages are profoundly responsive to their tissue microenvironment, but how that affects their pathogen response functions has not been investigated systematically. Here we studied how their signaling response is affected by six polarizing cytokines. We found each modulates their stimulus-responses highly specifically, producing distinct patterns of stimulus-discrimination. Thereby, these stimulus-response specificities may be used to describe a landscape of functional macrophage states. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/485991v1_ufig1.gif" ALT="Figure 1"> View larger version (77K): org.highwire.dtl.DTLVardef@1d34d5forg.highwire.dtl.DTLVardef@17cc0eaorg.highwire.dtl.DTLVardef@15d6022org.highwire.dtl.DTLVardef@1526f72_HPS_FORMAT_FIGEXP M_FIG C_FIG