PARP1 and infection: Although we were unable to detect PAR formation in M.tb-infected cells, treatment with relevant cytokines (TNFα) or bacterial antigen (LPS) elicited PAR formation similar to MNNG in murine macrophages, primary human peripheral blood mononuclear cells (PBMCs) and HeLa cells (Supplementary Figure 2), indicating that primary and immortalized macrophage-like cells of mouse and human origin can activate PARP1 in response to infection-associated stimuli.