Two Roles for the Tenebrio molitor Relish in the Regulation of Antimicrobial Peptides and Autophagy-Related Genes in Response to Listeria monocytogenes

Relish is a key NF-κB transcription factor of the immune-deficiency (Imd) pathway that combats infection by regulating antimicrobial peptides (AMPs). Understanding of the fundamental role of Tenebrio molitor Relish (TmRelish) in controlling of Listeria monocytogenes virulence through the regulation of both AMPs and autophagy-related (ATG) genes is unclear. Here, we show that TmRelish transcripts were highly abundant in the larval fat body and hemocytes compared to the gut upon L. monocytogenes infection. Furthermore, significant mortality was observed in TmRelish-silenced larvae after intracellular insult. To investigate the cause of this lethality, we measured the induction of AMPs and ATG genes in the TmRelish dsRNA-treated T. molitor larvae. The expression of TmTenecin-1, TmTenecin-4, TmColeptericin-1, TmAttacin-2, and TmCecropin-2 were suppressed in the fat body and hemocytes of dsTmRelish-injected larvae during L. monocytogenes infection. In addition, TmRelish knockdown led to a noticeable downregulation of TmATG1 (a serine-threonine protein kinase) in the fat body and hemocytes of young larvae 6 h post-infection (pi). The notable increase of autophagy genes in the early stage of infection (6 h pi), suggesting autophagy response is crucial for Listeria clearance. Taken together, these results suggest that TmRelish plays pivotal roles in not only regulation of AMP genes but also induction of autophagy genes in response to L. monocytogenes challenge in fat body and hemocytes of T. molitor larvae. Furthermore, negative regulation of several AMPs by TmRelish in the fat body, hemocytes, and gut leaves open the possibility of a crosstalk between Toll and Imd pathway.

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Aedes aegypti (Diptera: Culicidae) Immune Responses with Different Feeding Regimes Following Infection by the Entomopathogenic Fungus Metarhizium anisopliae

Insects ◽

10.3390/insects11020095 ◽

2020 ◽

Vol 11 (2) ◽

pp. 95 ◽

Cited By ~ 1

Author(s):

Sara Cabral ◽

Adriano de Paula ◽

Richard Samuels ◽

Rodrigo da Fonseca ◽

Simone Gomes ◽

...

Keyword(s):

Aedes Aegypti ◽

Immune Responses ◽

Antimicrobial Peptides ◽

Fungal Infection ◽

Fat Body ◽

Negative Regulator ◽

Toll Pathway ◽

Promising Alternative ◽

Imd Pathway ◽

Feeding Regimes

The mosquito Aedes aegypti is the most notorious vector of illness-causing viruses. The use of entomopathogenic fungi as bioinsecticides is a promising alternative for the development of novel mosquito control strategies. We investigate whether differences in immune responses could be responsible for modifications in survival rates of insects following different feeding regimes. Sucrose and blood-fed adult A. aegypti females were sprayed with M. anisopliae 1 × 106 conidia mL−1, and after 48 h, the midgut and fat body were dissected. We used RT-qPCR to monitor the expression of Cactus and REL1 (Toll pathway), IMD, REL2, and Caspar (IMD pathway), STAT and PIAS (JAK-STAT pathway), as well as the expression of antimicrobial peptides (Defensin A, Attacin and Cecropin G). REL1 and REL2 expression in both the midgut and fat body were higher in blood-fed fungus-challenged A. aegypti than in sucrose-fed counterparts. Interestingly, infection of sucrose-fed insects induced Cactus expression in the fat body, a negative regulator of the Toll pathway. The IMD gene was upregulated in the fat body in response to fungal infection after a blood meal. Additionally, we observed the induction of antimicrobial peptides in the blood-fed fungus-challenged insects. This study suggests that blood-fed A. aegypti are less susceptible to fungal infection due to the rapid induction of Toll and IMD immune pathways.

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A protective role of gamma/delta T cells in primary infection with Listeria monocytogenes in mice.

Journal of Experimental Medicine ◽

10.1084/jem.175.1.49 ◽

1992 ◽

Vol 175 (1) ◽

pp. 49-56 ◽

Cited By ~ 246

Author(s):

K Hiromatsu ◽

Y Yoshikai ◽

G Matsuzaki ◽

S Ohga ◽

K Muramori ◽

...

Keyword(s):

T Cells ◽

Listeria Monocytogenes ◽

T Cell ◽

Primary Infection ◽

Early Stage ◽

Sublethal Dose ◽

Gamma Delta T Cells ◽

Gamma Delta ◽

Alpha Beta

We have previously reported that T cells bearing T cell receptors (TCRs) of gamma/delta type appear at a relatively early stage of primary infection with Listeria monocytogenes in mice. To characterize the early-appearing gamma/delta T cells during listeriosis, we analyzed the specificity and cytokine production of the gamma/delta T cells in the peritoneal cavity in mice inoculated intraperitoneally with a sublethal dose of L. monocytogenes. The early-appearing gamma/delta T cells, most of which were of CD4-CD8- phenotype, proliferated and secreted IFN-gamma and macrophage chemotactic factor in response to purified protein derivative from Mycobacterium tuberculosis, or recombinant 65-kD heat-shock protein derived from M. bovis but not to heat-killed Listeria. To further elucidate the potential role of the gamma/delta T cells in the host-defense mechanism against primary infection with Listeria, we examined the effects of in vivo administration of monoclonal antibodies (mAbs) against TCR-gamma/delta or TCR-alpha/beta on the bacterial eradication in mice infected with Listeria. Most of alpha/beta T cells or gamma/delta T cells were depleted in the peripheral lymphoid organs at least for 12 d after an intraperitoneal injection of 200 micrograms TCR-alpha/beta mAb or 200 micrograms TCR-gamma/delta mAb, respectively. An exaggerated bacterial multiplication was evident at the early stage of listerial infection in the gamma/delta T cells-depleted mice, whereas the alpha/beta T cell-depleted mice exhibited much the same resistance level as the control mice at this stage although the resistance was severely impaired at the late stage after listerial infection.(ABSTRACT TRUNCATED AT 250 WORDS)

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Autophagy in Tenebrio molitor Immunity: Conserved Antimicrobial Functions in Insect Defenses

Frontiers in Immunology ◽

10.3389/fimmu.2021.667664 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yong Hun Jo ◽

Jung Hee Lee ◽

Bharat Bhusan Patnaik ◽

Maryam Keshavarz ◽

Yong Seok Lee ◽

...

Keyword(s):

Cross Talk ◽

Expressed Sequence Tag ◽

Tenebrio Molitor ◽

Signaling Cascade ◽

Imd Pathway ◽

Pathway Activation ◽

Mealworm Beetle ◽

Cellular And Humoral Immunity ◽

Expressed Sequence

The yellow mealworm beetle (Tenebrio molitor) has been exploited as an experimental model to unravel the intricacies of cellular and humoral immunity against pathogenic infections. Studies on this insect model have provided valuable insights into the phenotypic plasticity of immune defenses against parasites and pathogens. It has thus been possible to characterize the hemocoelic defenses of T. molitor that rely on the recognition of non-self-components of pathogens by pattern recognition receptors (PRRs). The subsequent signaling cascade activating pathways such as the NF-κB controlled by Toll and IMD pathways lead to the synthesis of antimicrobial peptides (AMPs), onset of hemocyte-driven phagocytosis, and activation of the prophenoloxidase cascade regulating the process of melanization. Nevertheless, the activation of autophagy-mediated defenses of T. molitor against the facultative intracellular gram-positive bacterium Listeria monocytogenes provides clear evidence of the existence of a cross-talk between autophagy and the IMD pathway. Moreover, the identification of several autophagy-related genes (Atgs) in T. molitor transcriptome and expressed sequence tag (EST) databases has contributed to the understanding of the autophagy-signaling cascade triggered by L. monocytogenes challenge. Providing further evidence of the cross-talk hypothesis, TmRelish has been shown to be required not only for regulating the synthesis of AMPs through the PGRP-LE/IMD pathway activation but also for the expression of Atgs in T. molitor larvae following L. monocytogenes challenge. Notably, L. monocytogenes can stimulate the T. molitor innate immune system by producing molecules recognized by the multifunctional PRR (TmPGRP-LE), which stimulates intracellular activation of the IMD pathway and autophagy. Considering the conservation of autophagy components involved in combating intracellular pathogens, it will be interesting to extrapolate a dynamic cross-talk model of immune activation. This review summarizes the most significant findings on the regulation of autophagy in T. molitor during L. monocytogenes infection and on the role of the innate immunity machinery, including the NF-κB pathway, in the control of pathogenic load.

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TmAtg6 Plays an Important Role in Anti-Microbial Defense Against Listeria monocytogenes in the Mealworm, Tenebrio molitor

International Journal of Molecular Sciences ◽

10.3390/ijms21041232 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1232 ◽

Cited By ~ 1

Author(s):

Tariku Tesfaye Edosa ◽

Yong Hun Jo ◽

Maryam Keshavarz ◽

Ki Beom Park ◽

Jun Ho Cho ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Developmental Stages ◽

Fat Body ◽

Pupal Stage ◽

Tenebrio Molitor ◽

Larval Survival ◽

Related Gene ◽

Specific Expression ◽

Microbial Defense ◽

Different Tissues

Autophagy-related gene-6 (Beclin-1 in mammals) plays a pivotal role in autophagy and is involved in autophagosome formation and autolysosome maturation. In this study, we identified and characterized the autophagy-related gene-6 from Tenebrio molitor (TmAtg6) and analyzed its functional role in the survival of the insect against infection. The expression of TmAtg6 was studied using qRT-PCR for the assessment of the transcript levels at various developmental stages in the different tissues. The results showed that TmAtg6 was highly expressed at the 6-day-old pupal stage. Tissue-specific expression studies revealed that TmAtg6 was highly expressed in the hemocytes of late larvae. The induction patterns of TmAtg6 in different tissues of T. molitor larvae were analyzed by injecting Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, or Candida albicans. The intracellular Gram-positive bacteria, L. monocytogenes, solely induced the expression of TmAtg6 in hemocytes at 9 h-post-injection, whilst in the fat body and gut, bimodal expression times were observed. RNAi-mediated knockdown of the TmAtg6 transcripts, followed by a challenge with microbes, showed a significant reduction in larval survival rate against L. monocytogenes. Taken together, our results suggest that TmAtg6 plays an essential role in anti-microbial defense against intracellular bacteria.

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TmDorX2 positively regulates antimicrobial peptides in Tenebrio molitor gut, fat body, and hemocytes in response to bacterial and fungal infection

Scientific Reports ◽

10.1038/s41598-019-53497-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 11

Author(s):

Maryam Keshavarz ◽

Yong Hun Jo ◽

Ki Beom Park ◽

Hye Jin Ko ◽

Tariku Tesfaye Edosa ◽

...

Keyword(s):

Transcription Factors ◽

Antimicrobial Peptides ◽

Post Infection ◽

Fat Body ◽

Tenebrio Molitor ◽

Malpighian Tubules ◽

Whole Body ◽

Mrna Levels ◽

E Coli ◽

Pathogen Invasion

AbstractDorsal, a member of the nuclear factor-kappa B (NF-κB) family of transcription factors, is a critical downstream component of the Toll pathway that regulates the expression of antimicrobial peptides (AMPs) against pathogen invasion. In this study, the full-length ORF of Dorsal was identified from the RNA-seq database of the mealworm beetle Tenebrio molitor (TmDorX2). The ORF of TmDorX2 was 1,482 bp in length, encoding a polypeptide of 493 amino acid residues. TmDorX2 contains a conserved Rel homology domain (RHD) and an immunoglobulin-like, plexins, and transcription factors (IPT) domain. TmDorX2 mRNA was detected in all developmental stages, with the highest levels observed in 3-day-old adults. TmDorX2 transcripts were highly expressed in the adult Malpighian tubules (MT) and the larval fat body and MT tissues. After challenging the larvae with Staphylococcus aureus and Escherichia coli, the TmDorX2 mRNA levels were upregulated 6 and 9 h post infection in the whole body, fat body, and hemocytes. Upon Candida albicans challenge, the TmDorX2 mRNA expression were found highest at 9 h post-infection in the fat body. In addition, TmDorX2-knockdown larvae exposed to E. coli, S. aureus, or C. albicans challenge showed a significantly increased mortality rate. Furthermore, the expression of 11 AMP genes was downregulated in the gut and fat body of dsTmDorX2-injected larvae upon E. coli challenge. After C. albicans and S. aureus challenge of dsTmDorX2-injected larvae, the expression of 11 and 10 AMPs was downregulated in the gut and fat body, respectively. Intriguingly, the expression of antifungal transcripts TmTenecin-3 and TmThaumatin-like protein-1 and -2 was greatly decreased in TmDorX2-silenced larvae in response to C. albicans challenge, suggesting that TmDorX2 regulates antifungal AMPs in the gut in response to C. albicans infection. The AMP expression profiles in the fat body, hemocytes, gut, and MTs suggest that TmDorX2 might have an important role in promoting the survival of T. molitor larvae against all mentioned pathogens.

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The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

Perspectives on Language Learning and Education ◽

10.1044/lle15.2.50 ◽

2008 ◽

Vol 15 (2) ◽

pp. 50-59 ◽

Cited By ~ 1

Author(s):

Amy Philofsky

Keyword(s):

Language Development ◽

Critical Role ◽

Children With Autism ◽

Autism Spectrum ◽

Children With Asd ◽

Prevalence Estimates ◽

Notable Increase ◽

Screening Assessment ◽

Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

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