Borrelia burgdorferi infection induces long-term memory-like responses in macrophages with tissue-wide consequences in the heart
Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and other less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound downregulation of mitochondrial components. We also characterize the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced IRF-4-dependent inflammatory responses. In vitro, glycolysis inhibition reduces the production of TNF by memory macrophages whereas in vivo, it produces the reversion of the Irf4-induced memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo. Overall design: Genome-wide changes in gene expression in murine hearts from mice infected at different time points with Borrelia burgdorferi as well as those from mice infected and treated with a glycolysis inhibitor. Groups corresponding to times of infection 0, 7, 21 and 54 days as well as control-treated and 3-PO treated over the course of 5 weeks were generated by RNAseq.