Further notes about the morphostasis concept – split files

(55) Fresh thoughts about phylogenetic/ontogenetic roll-out of immune defences

I have suggested, in "Flushing out the phlogiston", that the defence barrages are rolled out in an ontogenetic sequence that follows the phylogenetic acquisition of each new barrage. These constitute a series of defence shells or barrages that deal with threats in an inner to outer shell sequence. When an inner barrage deals effectively with the crisis (the threat/organism/disorder is successfully neutralised) then there is no need for an outer barrage (shell) to be mobilised.

Now, I have overlooked an important consequence of this in that activation of complement, opsonisation and consequent ingestion by a cell (amateur or professional phagocyte), will lead to a successful neutralisation. There is no need to go on to recruit aggressive adaptive immune activity and, indeed, the outcome is the quiet disposal of the threat and – quite likely – a classification of any generated debris as suitable for future tolerance. That is why we see pathogenic organisms ("pathogerms") targeting the complement system to circumvent this protection and allow them to go on to do damage (create a nutrient substrate).

Apoptosis is, itself, an innate barrage that – because debris has been efficiently cleared – leaves no necessity to roll out aggressive adaptive immune responses to relevant (cleared) debris.