Eicosanoid-mediated immunity in insects

Kim, Yonggyun; Ahmed, Shabbir; Stanley, David; An, Chunju

doi:10.1016/j.dci.2017.12.005

Cited by 116 publications

(106 citation statements)

References 143 publications

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…Inhibition of PLA 2 activity can block all eicosanoid biosynthesis, decreasing eicosanoids to below their signaling capacity. Effects of eicosanoids on induction of immune‐associated genes in different insect systems have been reported (Y. Kim, Ahmed, Stanley, & An, ). Recently, Zhang et al () have shown that a small heat shock protein (sHSP21.4) of Antheraea pernyi plays a crucial role in expression of various immune‐associated genes.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Kim

Choi

Jung

et al. 2018

Arch Insect Biochem Physiol

Self Cite

View full text Add to dashboard Cite

An entomopathogenic bacterium Photorhabdus temperata subsp. temperata (Ptt) infects insect hemocoel by the vectoring activity of its symbiotic nematode, Heterorhabditis megidis. The bacterium induces host immunosuppression by inhibiting eicosanoid biosynthesis. This study investigated the role of eicosanoids in immune responses of the beet armyworm, Spodoptera exigua, in the early bacterial infection stage (first 3 hr postinfection [PI]). After infection with the nonpathogenic Escherichia coli (Ec), the bacterium maintained its population for the first 3 hr PI, then rapidly decreased in numbers. During the 3 hr PI of Ptt, this pathogenic bacterium also did not show any significant change in bacterial population. However, Ptt rapidly increased its population size after the initial lag phase, inducing fatal septicemia. This study further analyzed cellular and humoral immune responses of the beet armyworm during the initial 3 hr PI. During this early stage, challenge with Ec stimulated hemocyte-spreading behavior along with extensive F-actin growth. However, Ptt infection suppressed hemocyte spreading. Expression levels of three antimicrobial peptides (lysozyme, gloverin, and gallerimycin) were significantly inhibited during Ptt infection. Phospholipase A activity was significantly induced during the early infection stage of Ec, but not during Ptt infection. Addition of eicosanoid biosynthesis inhibitors significantly reversed the initial immunosuppression. These results suggest that, during the early infection stage, Ptt can shutdown eicosanoid biosynthesis which can prevent acute immune responses of host insects.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Eicosanoids mediate both cellular and humoral immune responses (Y. Kim et al, ). Ptt suppressed eicosanoid biosynthesis during the early infection stage by preventing PLA 2 activation.…”

Section: Discussionmentioning

confidence: 99%

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Kim

Choi

Jung

et al. 2018

Arch Insect Biochem Physiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…After microbial pathogen infection, pattern recognition receptors can recognize specific pathogen‐associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) in Gram‐negative bacteria, peptidoglycan (PGN) and lipoteichoic acid in Gram‐positive bacteria, β‐1,3‐glycan in fungi, and unmethylated CpG motif in bacterial DNA (Janeway & Medzhitov, ). The recognition signal is propagated to hemocytes and fat body via immune mediators such as eicosanoids (Kim, Ahmed, Stanley, & An, ). Hemocytes are mostly involved in cellular immune responses such as phagocytosis, nodulation, and encapsulation (Lavine & Strand, ) while fat body is the main source of antimicrobial peptides (AMPs) for humoral immune response (Imler, ).…”

Section: Introductionmentioning

confidence: 99%

Toll/IMD signal pathways mediate cellular immune responses via induction of intracellular PLA₂ expression

Sajjadian

Vatanparast

Kim

2019

Arch Insect Biochem Physiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Eicosanoids mediate events in homeostasis, immunity, reproduction and fluid secretion in insects (Stanley and Kim, ). Thus, any inhibition of PLA 2 activity can result in significant physiological alterations and attenuate insect survival (Kim et al , ). Two types of nonvenom PLA 2 s have been identified: sPLA 2 in Tribolium castaneum (Shrestha and Kim, ) and Spodoptera exigua (Vatanparast et al , ) and iPLA 2 in S. exigua (Park et al , ).…”

Section: Introductionmentioning

confidence: 99%

“…These PLA 2 s are associated with releasing PUFAs from PL. They play a crucial role in immunity (Kim et al , ).…”

Section: Introductionmentioning

confidence: 99%

Secretion of secretory phospholipase A₂ into Spodoptera exigua larval midgut lumen and its role in lipid digestion

Sajjadian

Vatanparast

Stanley

et al. 2019

Insect Molecular Biology

View full text Add to dashboard Cite

In insects, lipid digestion is controversial because insects have no bile salts to solubilize dietary lipids. One hypothesis is that a secretory type of phospholipase A2 (sPLA2) provides lysophospholipid (LPL) from dietary phospholipids (PLs). We identified a sPLA2, Se‐sPLA2, in beet armyworm, Spodoptera exigua, that hydrolyses PLs at sn‐2. Our goal was to investigate its role in lipid digestion. Se‐sPLA2 was expressed in the entire alimentary canal. Incubating the isolated midgut in a cell culture medium led to secretion of Se‐sPLA2 and other proteins. Ex vivo RNA interference (RNAi) of Se‐sPLA2 expression in isolated midgut culture led to significantly decreased Se‐sPLA2 secretion into the medium. Feeding double‐stranded RNA specific to Se‐sPLA2 to larvae suppressed sPLA2 activity in gut contents. A recombinant Se‐sPLA2 was susceptible to benzylideneacetone (BZA), a specific PLA2 inhibitor. After feeding BZA to larvae, we recorded significant decreases in gut content sPLA2 activity, body growth and total haemolymph lipid contents. RNAi against Se‐sPLA2 resulted in reduced digestibility. Addition of a specific LPL, 1‐palmitoyl‐sn‐glycero‐3‐phosphocholine, to BZA‐treated larvae rescued digestibility and larval growth. These results strongly bolster our hypothesis that Se‐sPLA2 secreted from the midgut acts in lipid digestion by providing necessary LPL to solubilize dietary neutral lipids.

show abstract

Eicosanoid-mediated immunity in insects

Cited by 116 publications

References 143 publications

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Toll/IMD signal pathways mediate cellular immune responses via induction of intracellular PLA₂ expression

Secretion of secretory phospholipase A₂ into Spodoptera exigua larval midgut lumen and its role in lipid digestion

Contact Info

Product

Resources

About

Eicosanoid-mediated immunity in insects

Cited by 116 publications

References 143 publications

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Eicosanoid mediation of immune responses at early bacterial infection stage and its inhibition by Photorhabdus temperata subsp. temperata, an entomopathogenic bacterium

Toll/IMD signal pathways mediate cellular immune responses via induction of intracellular PLA2 expression

Secretion of secretory phospholipase A2 into Spodoptera exigua larval midgut lumen and its role in lipid digestion

Contact Info

Product

Resources

About

Toll/IMD signal pathways mediate cellular immune responses via induction of intracellular PLA₂ expression

Secretion of secretory phospholipase A₂ into Spodoptera exigua larval midgut lumen and its role in lipid digestion