Merge branch 'lpaoli-main-patch-24968' into 'main'

Init general concept page abortive infection

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content/2.general-concepts/1.abortive-infection.md

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 title: Abortive Infection
 layout: article
+contributors: 
+  - Lucas Paoli
+relevantAbstracts:
+  - doi: 10.1128/jb.68.1.36-42.1954
+  - doi: 10.1016/0006-3002(61)90455-3
+  - doi: 10.1016/0022-2836(68)90078-8
+  - doi: 10.1128/jvi.4.2.162-168.1969
+  - doi: 10.1128/jvi.13.4.870-880.1974
+  - doi: 10.1128/mr.45.1.52-71.1981
+  - doi: 10.3168/jds.S0022-0302(90)78904-7
+  - doi: 10.1016/S0960-9822(00)00124-X
+  - doi: 10.1111/j.1365-2958.1995.tb02255.x
+  - doi: 10.1016/j.mib.2005.06.006
+  - doi: 10.1146/annurev-virology-011620-040628
+  - doi: 10.1016/j.mib.2023.102312
+  - doi: 10.1038/s41579-023-00934-x
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+The term abortive infection was coined in the 1950s :ref{doi=10.1128/jb.68.1.36-42.1954} to describe the observations that a fraction of the bacterial population did not support phage replication. This phenomenon, also called phage exclusion, was identified in multiple systems across the following decades :ref{doi=10.1016/0006-3002(61)90455-3,10.1016/0022-2836(68)90078-8,10.1128/jvi.4.2.162-168.1969,10.1128/jvi.13.4.870-880.1974} and reviewed extensively :ref{doi=10.1128/mr.45.1.52-71.1981,10.3168/jds.S0022-0302(90)78904-7,10.1111/j.1365-2958.1995.tb02255.x}. In the following years, and through the resolution of molecular mechanisms of key defense systems such as Rex or Lit, abortive infection became synonymous with infection-induced controlled cell-death. Controlled cell death upon detection of the phage infection stops the propagation of the phage and protects the rest of the bacterial population :ref{doi=10.1016/S0960-9822(00)00124-X,10.1016/j.mib.2005.06.006}. Abortive infection can thus be thought of as a form of bacterial altruism.
+
+With the recent developments in phage-defense systems and microbial immunity (see :ref{doi=10.1038/s41579-023-00934-x} for a review), many newly identifed anti-phage defense systems are thought to function through abortive infection. Abortive defense systems often detect the phage infection at the later stage through protein sensing or the monitoring of host integrity but can also be based on nucleic acid sensing. Upon sensing, a diverse set of effectors can be used to reduce metabolism or induce cell-death (e.g., NAD+ depletion, translation interruption or membrane depolarisation). The diversity of and mechanisms of abortive infection were recently reviewd here :ref{doi=10.1146/annurev-virology-011620-040628}, while the evolutionary success of this paradoxical altruistic form of immunity has recently been discussed here :ref{doi=10.1016/j.mib.2023.102312}.
+
+Although abortive infection is currently often understood as leading to cell-death, it should be noted that its original definition appeared to be broader and that some mechanisms currently included as abortive infection may only lead to metabolic stalling or dormancy. 
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