Immune memory: an evolutionary perspective

Abstract

The innate immune system, through pattern recognition receptors, intercepts any kind of pathogen and reacts through chemotactic, phagocyting, cytokines-secreting and cell-killing mechanisms in a very quick and effective way. Meanwhile, the adaptive immunity arm, through dendritic and T and B cells memory activation, is alerted and starts, more slowly, to produce antibodies, seen thanks to the progress of immunological investigations in comparative vertebrates, invertebrates, and vegetal models.However, it has been stated that the innate immune system also displays adaptive potential in terms of reinfection resistance through immune memory, in addition to the modulation of responses against repeated low doses of lipopolysaccharides (Lps) or cross-immunization, starting from one pathogenic species and extending to others.

Contextual Fear Memory Maintenance Changes Expression of pMAPK, BDNF and IBA-1 in the Pre-limbic Cortex in a Layer-Specific Manner

“…The particular experimental design utilised here allowed us to examine whether PL may be involved in the long-term maintenance of contextual fear memories. This advances previous knowledge which suggests this region is essential for the expression of contextual fears (see review by Rozeske et al, 2015 and research studies by Frankland et al, 2004;Corcoran and Quirk, 2007;Laurent and Westbrook, 2008;Goshen et al, 2011;Stevenson, 2011;Stern et al, 2013), but not the formation of contextual fears (Morgan et al, 1993;Morrow et al, 1999b;Fernandez Espejo, 2003;Antoniadis and McDonald, 2006;Bissière et al, 2008). However, the ability to accurately study fear expression vs. fear maintenance is difficult.…”

“…In contrast, research studies on the mPFC suggest it plays a different role (Fanselow, 2010;Gilmartin et al, 2014;Rozeske et al, 2015). Studies have demonstrated that inhibition, damage, manipulation or removal of the mPFC prior to CFC to have no effect on subsequent fear-related freezing to context (Morgan et al, 1993;Morrow et al, 1999b;Fernandez Espejo, 2003;Antoniadis and McDonald, 2006;Bissière et al, 2008). However, the involvement of the mPFC, or more specifically, the PL, in the expression of these contextual fear memories is well documented (see review by Frankland et al, 2004;Corcoran and Quirk, 2007;Laurent and Westbrook, 2008;Goshen et al, 2011;Stevenson, 2011;Stern et al, 2013;Rozeske et al, 2015).…”

“…Interestingly, these studies demonstrate a similar function for PL as the hippocampus in CFC. Contextual fear memories can form if either PL or hippocampus are damaged prior to, but not after, CFC (see reviews : Fanselow, 2010;Chaaya et al, 2018 andMorgan et al, 1993;Young et al, 1994;Morrow et al, 1999a,b;Rudy et al, 2002;Fernandez Espejo, 2003;Antoniadis and McDonald, 2006;Bissière et al, 2008). Interestingly, previous research has shown that contextual fear memories created in the absence of the hippocampus seem to more heavily rely upon the PL (Zelikowsky et al, 2013).…”

“…Interestingly, various studies have demonstrated damage or interference to the mPFC prior to CFC to have little effect on its consolidation (Morgan et al, 1993;Morrow et al, 1999a;Fernandez Espejo, 2003;Antoniadis and McDonald, 2006;Bissière et al, 2008). However, evidence of mPFC, or more specifically pre-limbic cortex (PL), involvement in the expression of fear-related freezing behaviour to context is well documented (Frankland et al, 2004;Corcoran and Quirk, 2007;Laurent and Westbrook, 2008;Goshen et al, 2011;Stevenson, 2011;Stern et al, 2013).…”

Trained Immunity as an Adaptive Branch of Innate Immunity

“…In recent years, however, conclusive evidence has accumulated demonstrating that innate immunity may also possess some adaptation ability. It recognizes and remembers the non-self, the foreign molecular patterns not only in vertebrates but also in invertebrates [ 7 , 8 , 9 , 10 ], and even in plants, and is termed “systemic acquired resistance” [ 11 , 12 , 13 ] (for review, see Gourbal et al, 2018 [ 14 ]).…”