IFNB1 and infection: The results observed in Fig 4 suggested that it is important to take into account the number of intracellular bacteria present in macrophages following infection when comparing levels of secreted IFN-β.Therefore, when examining BMDMs for secreted levels of IFN-β, we infected these cells using the same OD-based calculation as before, and additionally plated macrophage whole cell lysates at the end of the infection period (2hpi).