Immunological stimuli change expression of genes and neutrophil function in fathead minnow Pimephales promelas Rafinesque

Abstract

Fathead minnows Pimephales promelas were exposed to lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid [poly(I:C)] to observe immunological responses during simulated bacterial and viral challenge at the level of gene expression and granulocyte function. Complementary DNA libraries were created from LPS- and poly(I:C)-treated fish and c. 5000 expressed sequence tags (ESTs) were sequenced. The ESTs were subjected to BLASTx analysis and 1500 genes were annotated, grouped by function and 20 immune genes were selected for expression studies by real-time PCR. Lipopolysaccharide treatment significantly downregulated expression of interferon regulatory factor 2 binding protein 1 (nine-fold), Chemokine (C-X-C motif) ligand 12a (three-fold) and TNF-related apoptosis-inducing ligand, TRAIL (two-fold). In poly(I:C)-treated fish, a significant upregulation was observed for IFN-inducible and antiviral proteins belonging to the family of Mx proteins (73-fold) and chemokine CCL-C5a (28-fold). Blood neutrophil count was significantly increased in poly(I:C)-treated fish at 24 and 48 h post-injection. Neutrophil extracellular trap release and respiratory burst of kidney granulocytes were suppressed in poly(I:C)-treated fish, while degranulation of primary granules was not affected significantly by the treatment. The changes in gene expression and neutrophil function in P. promelas exposed to LPS and poly(I:C) support the use of this species as an alternative model for studies of pathogen effects on the innate immune system of fishes.

Characterization and expression of NADPH oxidase genes in stimulated splenic neutrophils of tilapia, Oreochromis niloticus by a mix of traditional Chinese medicine and Bacillus species (TCMBS)

“…Neutrophil defence mechanism involves the release of respiratory burst as well as neutrophil extracellular traps (NET) release to kill pathogens. Neutrophils rely on NADPH oxidase system to ferry electrons across cell membranes into phagocytic vacuoles during respiratory burst to create ROS which stimulates the release of the digestive enzymes responsible for microbial deaths (Jovanovic, Goetz, Goetz, & Palić, ). In the present study, TCMBS application showed increased neutrophil induced immune defence readiness through a significant increase in the production of ROS in splenic neutrophils.…”

Immune-Challenged Fish Up-Regulate Their Metabolic Scope to Support Locomotion

“…Individuals were challenged with an intra-peritoneal injection of LPS (Sigma; St. Louis, USA; L4005; 10μg/g fish at 1g/L [44]) or SRBC (Sigma R3378; 20μg/g fish at 1g/L [42, 45]) for experimental treatments, and 0.01mL of saline solution (PBS) for controls. Prior to injection, all fish were lightly anesthetized in a clove oil solution, and after injection animals were placed immediately in aged tap-water where they recovered within 1–2 minutes.…”

Immune responses and gut morphology in Senegalese sole (Solea senegalensis) fed dietary probiotic supplementation and following exposure toPhotobacterium damselaesubsp.piscicida

“…In this study, the relative proportion of thrombocytes, lymphocytes and monocytes varied significantly following 15 days after Phdp exposure, compared to control fish exposed to PBS. In contrast, no significant differences were found in thrombocyte, lymphocyte and monocyte counts, 24 and 48 h after injecting fathead minnow, Pimephales promelas (Rafinesque), with different pathogen‐associated molecular patterns such as lipopolysaccharides and polyinosinic‐polycytidylic acid (Jovanovic, Goetz, Goetz & Palić ). A reduction in the number of blood lymphocytes has been reported in fish after bacterial insults (Lamas, Santos, Bruno, Toranzo & Anadón ; Balfry, Shariff & Iwama ; Garcia et al .…”