Fig. 3: Coordination of innate immune responses in bacterial cells.

A Numerical simulations of Model 2 show that bacterial suicide could take place in a region of the infection space that overlaps with fast phages. This implies that Abi systems could neutralize phages that are not susceptible to restriction nucleases. B The suicide region produced by an alternative Abi system (described by equations (4)) is similar to that shown in (A). C Changing the values of the parameters of equation (3) in Model 2 gives raise to different suicide regions (shown in clear and dark blue, respectively). D A state of dormancy induced by Abi systems in infected cells reduces the rate of phage replication. As a consequence, host cells can resort to suicidal death against phages that would otherwise escape the action of bacterial immunity (1). A sufficiently large reduction in the rate of viral DNA replication by Abi systems may allow for nucleases to eliminate fast phages, preventing both the spread of the infection and the suicide of the host cell (2). The details of the simulations are provided in the “Methods” section.