Autonomous immunity is a set of immune mechanisms present in practically
every cell of a multicellular organism. They include immune mechanisms based on
nuclear acids, such as RNA interference (RNAi). Small RNAs generated from
pathogen dsRNAs guide nucleases to the pathogenic nucleic acids. In addition, RNAi
restricts the expression of transposable elements by establishing transcriptionrepressing
chromatin over DNA regions that encode such elements. Other autonomous
mechanisms prevent the entry of viruses into cells, detect and destroy non-self nucleic
acids, restrict pathogen growth and replication, prevent pathogen release, and induce
regulated cell death if the infection cannot be suppressed. Infected cells release
interferons and other cytokines that alert neighboring cells and preventively induce
defensive mechanisms in them. Pathogens express pathogen-associated molecular
patterns (PAMPs), which are recognized by pattern-recognition receptors (PRRs).
These receptors also recognize damaged “self” molecules expressing damageassociated
molecular patterns. Infection can also be sensed indirectly through changes
in the functioning of some key cellular molecules. Stress and infection can lead to the
formation of inflammasomes triggering production and secretion of pro-inflammatory
cytokines.
Keywords: Argonaute, Drosha, Dicer, Damage-associated molecular pattern,
Danger theory, Effector immunity, Inflammasome, NLR, Pathogen-associated
molecular patterns, Pattern recognition receptor, piRNAs, RNA interference,
siRNAs, TLR.
