Highlights•Organisms lacking an adaptive immune system can mount resistance to
secondary infections.•NK cells and monocytes have adaptive (memory) characteristics.• …

Over the last decades, there was increasing evidence for the presence of innate immune
memory in living organisms. In this review, we compare the innate immune memory of …

Significance: A growing body of clinical and experimental evidence has challenged the
traditional understanding that only the adaptive immune system can mount immunological …

The inability of innate immunity to build an immunological memory is considered a main
difference with adaptive immunity. This concept has been challenged by studies in plants …

The evolutionary benefits of immunological memory are important: whereas antibodies can
be transmitted to offspring by their mother and thereby benefit the species, T cell memory …

Innate immune cells can potentiate the response to reinfection through an innate form of
immunological memory known as trained immunity. The potential of this fast-acting …

The mechanisms underlying innate immune memory have been extensively explored in the
last decades but are in fact largely unknown. Although the specificity of adaptive immune …

Immune memory is a defining feature of the acquired immune system, but activation of the
innate immune system can also result in enhanced responsiveness to subsequent triggers …

Over the past decade, compelling evidence has unveiled previously overlooked adaptive
characteristics of innate immune cells. Beyond their traditional role in providing short, non …

Recent investigations reveal memory-like adaptive responses of the innate immune system
to sequential pathogen challenge. Of note, opposing effects that include both sensitization …