Putative apolipoprotein A‐I, natural killer cell enhancement factor and lysozyme g are involved in the early immune response of brown‐marbled grouper, Epinephelus fuscoguttatus, Forskal, to Vibrio alginolyticus

Abstract

The gram-negative bacterium, Vibrio alginolyticus, has frequently been identified as the pathogen responsible for the infectious disease called vibriosis. This disease is one of the major challenges facing brown-marbled grouper aquaculture, causing fish farmers globally to suffer substantial economic losses. The objective of this study was to investigate the proteins involved in the immune response of brown-marbled grouper fingerlings during their initial encounter with pathogenic organisms. To achieve this objective, a challenge experiment was performed, in which healthy brown-marbled grouper fingerlings were divided into two groups. Fish in the treated group were subjected to intraperitoneal injection with an infectious dose of V. alginolyticus suspended in phosphate-buffered saline (PBS), and those in the control group were injected with an equal volume of PBS. Blood samples were collected from a replicate number of fish from both groups at 4 h post-challenge and analysed for immune response-related serum proteins via two-dimensional gel electrophoresis. The results showed that 14 protein spots were altered between the treated and control groups; these protein spots were further analysed to determine the identity of each protein via MALDI-TOF/TOF. Among the altered proteins, three were clearly overexpressed in the treated group compared with the control; these were identified as putative apolipoprotein A-I, natural killer cell enhancement factor and lysozyme g. Based on these results, these three highly expressed proteins participate in immune response-related reactions during the initial exposure (4 h) of brown-marbled grouper fingerling to V. alginolyticus infection.

Identification of immune response‐related genes and signalling pathways in spleen of Vibrio parahaemolyticus‐infected Epinephelus fuscoguttatus (Forskal) by next‐generation sequencing

“…This is similar to two isoforms of peroxiredoxin which were found to be downregulated in the class of antioxidant activity (Table S1), but peroxiredoxin protein was reported to be highly expressed in grouper serum at 4 h post‐challenge with Vibrio alginolyticus (Low et al . ). Thus, plausible explanation for the circumstance where peroxiredoxin transcript was found low in copy number is that the translation rate of this transcript into functional protein was high.…”

Omics Strategies in Current Advancements of Infectious Fish Disease Management

“…Vibrio hemorrhagic septicemia or vibriosis has a widespread infection in cultured groupers in Brunei Darussalam, Malaysia, Taiwan, Indonesia, Kuwait, Thailand, Singapore, and the Philippines [ 19 ]. The causative pathogens of vibriosis are from Gram-negative bacteria of Vibrio species, which include Vibrio parahaemolyticus , Vibrio alginolyticus , Vibrio vulnificus , Vibrio carchariae , Vibrio anguillarum , Vibrio ordalii , Vibrio harveyi , Vibrio mimicus , and many more from the family of Vibrionaceae [ 16 , 20 , 21 ]. The lack of study on vibriosis caused by other uncommon Vibrio species could impede further progression and development to prevent and control vibriosis measures in aquaculture [ 22 ].…”

“…Unlike mammals, fish are more dependent on the non-specific, innate defense system [ 15 ]. They are equipped with natural barriers that act as protective mechanisms: their skin and scales and the lytic proteins present in the mucus and sera [ 16 ]. While the innate defense system responds faster than the adaptive immunity of the species towards any foreign attack [ 17 ], the adaptive response of fish is essential for long-term immunological memory despite being implemented with a slight delay [ 18 ].…”

Mucosal responses of brown‐marbled grouper Epinephelus fuscoguttatus (Forsskål, 1775) following intraperitoneal infection with Vibrio harveyi

“…Previous studies have identified several anti‐inflammatory proteins in the serum of brown‐marbled grouper infected with Vibrio spp. via the intraperitoneal (IP) route, such as natural killer cell enhancement factor, apolipoprotein A‐I, lysozyme, parvalbumin, alpha‐2‐macroglobulin and nattectin (Low, Shamsudin, Abdullah, Chee, & Aliyu‐Paiko, 2015; Low, Shamsudin, Chee, Aliyu‐Paiko, & Idrus, 2014). IP administration of antigens has also been shown to stimulate an immune response at distant mucosal sites.…”