Fifty Shades of Immune Defense

Criscitiello, Michael F.; Figueiredo, Paul de

doi:10.1371/journal.ppat.1003110

Cited by 52 publications

(35 citation statements)

References 29 publications

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“…A number of studies on several insect species have provided evidence for phenomena that are reminiscent of immune memory, often called immune priming, which is enhanced resistance after prior exposure to pathogens (for review, see [2,3,4,5,6]). These studies have been conducive to the emerging awareness that the previous clear distinction between innate and adaptive immunity may need conceptual renewal [3,7,8,9]. …”

Section: Introductionmentioning

confidence: 99%

Increased Survival in the Red Flour Beetle after Oral Priming with Bacteria-Conditioned Media

2013

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Immune priming is defined as enhanced protection upon secondary exposure to a pathogen. Such enhanced resistance after prior exposure has been demonstrated for a number of insect species including the red flour beetle, Tribolium castaneum. In testing this phenomenon, the majority of studies have focused on introducing the pathogen into the insect's hemocoel via septic wounding through the cuticle. Although such septic injury can occur in nature, many pathogens enter their hosts via the oral route, i.e. by ingestion. Bacillus thuringiensis bacteria are well-known insect pathogens that infect their host orally. We found that T. castaneum larvae showed increased survival after oral exposure to B. thuringiensis, when they had been orally primed with filter-sterilized media in which spores of B. thuringiensis had been raised. Such priming was achieved only with a naturally pathogenic strain of B. thuringiensis and a strain that was made pathogenic by transfer of plasmids. Moreover, primed larvae were smaller in size 24 h after priming and had a longer developmental time, indicating that investment in such a response comes at a cost. However, the increased survival in primed larvae was not caused by larval size differences upon challenge.

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Section: Introductionmentioning

confidence: 99%

Increased Survival in the Red Flour Beetle after Oral Priming with Bacteria-Conditioned Media

2013

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“…How invertebrates make the critical distinction between friend and foe through the germlineencoded receptors of the innate immunity, in the absence of the fine-tuned specificity associated with the vertebrate adaptive immunity, is still very poorly understood. However, studies demonstrating phenomenological evidence for immune memory in invertebrates, as well as the capacity to generate tremendous PRR diversity at the genomic level or through alternative splicing, are challenging the long-held paradigm that innate immunity is non-specific and lacks memory (Schulenburg, et al 2007;Netea, et al 2011;Ziauddin and Schneider 2012;Criscitiello and de Figueiredo 2013). Hence it has been hypothesised that innate immune complexity, achieved through the diversification and expansion of the PRR complements, could provide invertebrates with the capacity to recognise specific ligands in order to manage their symbiotic bacterial communities.…”

Section: Invertebrates May Deploy Multiple Strategies For Managing Thmentioning

confidence: 99%

Deciphering the genomic toolkit underlying animal-bacteria interactions – insights through the demosponge Amphimedon queenslandica

Yuen¹

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All animals are inhabited by bacteria, and maintaining homeostasis in the multicellular environment of the host involves the complex balancing act of promoting the survival of symbionts while defending against intruders. Sponges (Porifera), in addition to housing diverse bacterial symbiont assemblages, also rely on bacteria filtered from the water column for nutrition. My research uses the genome-enabled demosponge, Amphimedon queenslandica, a member of one of the earliest-diverging animal phyletic lineages, as an experimental platform to investigate the genomic toolkit underpinning animal-bacteria interactions. Using comparative bioinformatics tools, I characterised a surprisingly large and complex repertoire of innate immune receptors from the NLR family of genes encoded in the A. queenslandica genome. I then used a high throughput RNAseq approach to profile the sponge's global transcriptomic response to foreign versus its own native bacteria. Conserved metazoan innate immune pathways were activated in response to both foreign and native bacteria. However, only the native bacteria elicited the expression of a more extensive suite of signalling pathways, involving TGF-β signalling and the transcription factors NF-κB and FoxO. Upregulation of the nutrient sensor AMPK in all treatments along with immune signalling genes, which all regulate FoxO activity, further suggests an interplay between metabolic homeostasis and immunity. Finally, I used microscopy to track the cellular-level processing of the different bacteria by the sponge. Consistent with the observed transcriptional response, the native bacteria were ingested by archaeocytes more rapidly than the foreign bacteria. The slower processing of foreign bacteria also correlated with the expression of numerous Nrf2-associated detoxification genes, indicative of cellular stress, only in response to foreign bacteria.iii Deciphering the genomic tool-kit underlying animal-bacteria interactions

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“…In terms of fighting pathogens, invertebrates possess a very efficient innate immune system (Iwanaga and Lee, 2005) that resembles that of vertebrates ( Litman et al, 2005;Söderhäll, 2010;Loker, 2012;Criscitiello and de Figueiredo, 2013). As an example, recent evidence suggests that the immune systems of invertebrates have some ability for immunological specificity and memory (Kurtz, 2005;Little et al, 2005).…”

Section: The Immune System Of Insectsmentioning

confidence: 99%