Developmental and Comparative Immunology

Renibacterium salmoninarum causes Bacterial Kidney Disease (BKD) in several fish species. Atlantic lumpfish, a cleaner fish, is susceptible to R. salmoninarum. To profile the transcriptome response of lumpfish to R. salmoninarum at early and chronic infection stages, fish were intraperitoneally injected with either a high dose of R. salmoninarum (1 × 109  cells dose-1 ) or PBS (control). Head kidney tissue samples were collected at 28- and 98-days post-infection (dpi) for RNA sequencing...

Stress-induced immunosuppression (SIIS) is one of the common problems in intensive poultry production, which brings enormous economic losses to the poultry industry. Accumulating evidence has shown that microRNAs (miRNAs) were important regulators of gene expression in the immune system. However, the miRNA-mediated molecular mechanisms underlying SIIS in chickens are still poorly understood. This study aimed to investigate the biological functions and regulatory mechanism of miRNAs in chicken SIIS. A stress-induced immunosuppression model was successfully established via daily injection of dexamethasone and analyzed miRNA expression in spleen...

The lacking of stable and susceptible cell lines has hampered research on pathogenic mechanism of crustacean white spot syndrome virus (WSSV). To look for the suitable cell line which can sustain WSSV infection, we performed the studies on WSSV infection in the Spodoptera frugiperda (Sf9) insect cells. In consistent with our previous study in vitro in crayfish hematopoietic tissue cells, the WSSV envelope was detached from nucleocapsid around 2 hpi in Sf9 cells, which was accompanied with the cytoplasmic transport of nucleocapsid toward the cell nucleus within 3 hpi...

This study investigated the effects of two distinct probiotics, Leuconostoc mesenteroides B4 (B4) and Bacillus pumilus D5 (D5), along with their combination, on the diet of white shrimp (Litopenaeus vannamei) during an eight-week feeding trial. The diets tested included B4 + dextran at 107 CFU/g feed (the B4 group), D5 alone at 107 CFU/g feed (the D5 group), and a combination of B4 + dextran and D5 at 5×106 CFU/g feed each (the B4+dextran + D5 group). Relative to the control group, those administered probiotics exhibited moderate enhancements in growth...

Oncorhynchus masou formosanus (Formosa landlocked salmon) is a critically endangered salmonid fish endemic to Taiwan. To begin to understand how its drastic change in lifestyle from anadromous to exclusively river-dwelling is reflected in its immune genes, we characterized the genes encoding six cytokines (IL-2A, IL-2B, IL-4/13A, IL-4/13B1, IL-4/13B2, and IL-17A/F2a) important for T cell responses as no genomic data is available for this fish. Interestingly, all genes appeared homozygous indicative of a genetic bottleneck...

CpG oligodeoxynucleotides (ODNs), as a novel type of adjuvant with immunomodulatory effects, are recognized by Toll-like receptors (TLRs) in Litopenaeus vannamei. In the present study, eleven LvTLRs-pCMV recombinants (rLvTLRs) were constructed to investigate the relationships between various CpG ODNs and different LvTLRs in human embryonic kidney 293T (HEK293T) cells, which was further confirmed by bio-layer interferometry (BLI) technique. The results of dual luciferase reporter assay showed that every LvTLR could activate multiple downstream genes, mainly including NF-κB, CREB, ISRE, IL-6-promoter, TNF-α-promoter and Myc, thereby inducing main signaling pathways in shrimps...

This study explores Neutrophil Extracellular Trap (NET) formation in equine neutrophils, which is crucial for eliminating infections and is implicated in various equine inflammatory diseases. We investigated the molecular pathways involved in NET release by equine neutrophils in response to stimuli. We use PMA, A23187, LPS, PAF, OZ, and cytokines, observing NET release in response to PMA, PAF, and A23187. In contrast, LPS, OZ, and the cytokines tested did not induce DNA release or did not consistently induce citrullination of histone 4...

Tilapia lake virus (TiLV) is an emerging virus that seriously threatens the tilapia industries worldwide. Interferon regulatory factors (IRFs), which are the crucial mediators regulating the response of interferon (IFN) to combat invading viruses, have not yet been reported in tilapia during TiLV infection. Here, six IRF (IRF1, IRF2, IRF4, IRF7, IRF8, and IRF9) homologs from tilapia were characterized and analyzed. These IRFs typically shared the conserved domains and phylogenetic relationship with IRF homologs of other species...

Schistosomiasis, urogenital and intestinal, afflicts 251 million people worldwide with approximately two-thirds of the patients suffering from the urogenital form of the disease. Freshwater snails of the genus Bulinus (Gastropoda: Planorbidae) serve as obligate intermediate hosts for Schistosoma haematobium, the etiologic agent of human urogenital schistosomiasis. These snails also act as vectors for the transmission of schistosomiasis in livestock and wildlife. Despite their crucial role in human and veterinary medicine, our basic understanding at the molecular level of the entire Bulinus genus, which comprises 37 recognized species, is very limited...

Olfactory receptors (OR), expressed on olfactory neurons, mediate the sense of smell. Recently, OR have also been shown to be expressed in non-olfactory tissues, including cells of the immune system. An analysis of single-cell transcriptomes of splenocytes of the grey short-tailed opossum (Monodelphis domestica) found OR are expressed on a subset of T cells, the γμ T cells, that are unique to marsupials and monotremes. A majority of opossum γμ T cells transcriptomes contain OR family 14 transcripts, specifically, from the OR14C subfamily...

Several immune-related genes, including Toll-like receptors (TLR), are associated with circadian rhythms in mammals. However, information on the circadian rhythmic expression of TLRs in fish is limited. In this study, we aimed to analyze the regulation of diel oscillations in the expression of TLR genes in Japanese medaka (Oryzias latipes). The expression analysis revealed diel expression patterns of tlr1, tlr5m, tlr21, and clock genes (bmal1 and clock1) under a 12 h light:12 h dark cycle. The clock gene response element (E-box) was identified in the transcriptional regulatory regions of tlr1, tlr5m, and tlr21...

Diseases caused by pathogens contribute to molecular adaptations in host immunity. Variety of viral pathogens challenging animal immunity can drive positive selection diversifying receptors recognising the infections. However, whether distinct virus sensing systems differ across animals in their evolutionary modes remains unclear. Our review provides a comparative overview of natural selection shaping molecular evolution in vertebrate viral-binding pattern recognition receptors (PRRs). Despite prevailing negative selection arising from the functional constraints, multiple lines of evidence now suggest diversifying selection in the Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptor (RLRs) and oligoadenylate synthetase (OAS)...

The model organism Caenorhabditis elegans is susceptible to infection by obligate intracellular pathogens, specifically microsporidia and viruses. These intracellular pathogens infect intestinal cells, or, for some microsporidia, epidermal cells. Strikingly, intestinal cell infections by viruses or microsporidia trigger a common transcriptional response, activated in part by the ZIP-1 transcription factor. Among the strongest activated genes in this response are ubiquitin-pathway members and members of the pals family, an intriguing gene family with cross-regulations of different members of genomic clusters...

Gasdermin (GSDM) proteins, as the direct executors of pyroptosis, are structurally and functionally conserved among vertebrates and play crucial roles in host defense against infection, inflammation, and cancer. However, the origin of functional GSDMs remains elusive in the animal kingdom. Here, we found that functional GSDME homologs first appeared in the cnidarian. Moreover, these animal GSDME homologs share evolutionarily conserved apoptotic caspase cleavage sites. Thus, we verified the functional conservation of apoptotic caspase-GSDME cascade in Hydra, a representative species of cnidarian...

Spring viremia of carp virus (SVCV) is a globally distributed virus that causes severe clinical symptoms and high mortality in fish belonging to the families Cyprinidae and Siluridae. To protect the host against viral infection, understanding the relatedness between viral susceptibility and antiviral mechanisms must be crucial. Thus, we evaluated the viral suppression efficacy of ribavirin by measuring the transcription levels of viral and immune genes in vitro. The results showed that following ribavirin treatment after SVCV infection (MOI 0...

Antimicrobial peptides (AMPs) are an essential part of the vertebrate innate immune system. Piscidins are a family of AMPs specific in fish. In our previous investigation, we identified four paralogous genes of piscidins in the orange-spotted grouper (Epinephelus coicodes), which exhibited distinct activities against bacteria, fungi, and parasitic ciliated protozoa. Piscidins demonstrated their capability to modulate the expression of diverse immune-related genes; however, their precise immunoregulatory functions remain largely unexplored...

Microbial drug resistance is becoming increasingly severe due to antibiotic abuse. The development and utilization of antimicrobial peptides is one of the important ways to solve this difficult problem. Crustins are a family of antimicrobial peptides that play important roles in the innate immune system of crustaceans. Several types of crustins exist in shrimp and their activities vary greatly. In the present study, we studied the immune function of one newly identified crustin and found that the type VI crustin encoding gene in Litopenaeus vannamei (LvCrustinVI) was mainly expressed in gills...

The fall armyworm, Spodoptera frugiperda, poses a significant threat as a highly destructive agricultural pest in many countries. Understanding the complex interplay between the insect immune system and entomopathogens is critical for optimizing biopesticide efficacy. In this study, we identified a novel microbial binding protein, SfMBP, in S. frugiperda. However, the specific role of SfMBP in the immune response of S. frugiperda remains elusive. Encoded by the LOC118269163 gene, SfMBP shows significant induction in S...

Klebsiella aerogenes (previously known as Enterobacter aerogenes) is a common opportunistic pathogen that infect the respiratory tract and central nervous system. However, how it interferes the host regulatory mechanism has not been previously described. When C. elegans were exposed to K. aerogenes, they exhibited a shorter lifespan compared to those fed with E. coli OP50. The time required for 50 % of L4 hermaphrodite nematodes to die when exposed to K. aerogenes was approximately 9 days, whereas it was about 18 days when fed with E...

There is limited knowledge regarding the blockade of cysteinyl leukotriene receptors (CysLTRs) and their effects in teleost fish. The present study investigated the effects of Zafirlukast, antagonist of CysLTR1 receptor, on the foreign body inflammatory reaction in Nile tilapia (Oreochromis niloticus). Zafirlukast-treated tilapia demonstrated a decrease in the formation of multinucleated foreign body giant cells and Langhans cells on the round glass coverslips implanted in the subcutaneous tissue, along with a significant reduction in white blood cell counts and decreased production of reactive oxygen species...