One of the things that first got me interested in immunology was
the concept that when our bodies are invaded by a pathogen, we
go through a sort of 'molecular' war. Antigen presenting cells,
such as Macrophages and Dendritic cells make up the scouts of
our immune 'armies' detecting the initial enemy incursion. From
here they report their findings to the T-cells and B-cells which
employ the destructive molecular weaponry we possess to remove
the pathogen. With such power however, I often wondered what
mechanisms existed to prevent the immune system from recognising
self tissues as an enemy. More importantly still, I wondered
where these mechanisms evolved from and how they learnt to
differentiate the enemy from us. At first I considered the
innate immune system relatively unimportant in this process-
just something to delay a pathogens replication until the big
guns of the adaptive immune system could come into play.
Essentially that the adaptive immune system was the one that did
all the important decisions