Bacterial viability differentially influences the immunomodulatory capabilities of potential host-derived probiotics in the intestinal epithelial cells of Atlantic cod Gadus morhua

Abstract

Aim: This study explored the effect of heat inactivation on the immunomodulatory capabilities of two potential host-derived probiotics (GP21 and GP12) on the intestinal epithelial cells (IEPC) derived from Atlantic cod. Methods and Results: The cells were isolated from the four segments of the gut, namely anterior intestine (AI), mid-intestine (MI), posterior intestine (PI) and rectum (RC). The IEPC cultures were exposed to live or heat-inactivated form of GP21 and GP12 for 24 h. The expression profiles of bacterial defence genes and cytokine genes in the probiotics-exposed IEPCs showed differential patterns. Heat inactivation did not drastically affect the immunomodulatory properties of the probiotics, and this was explicitly typified by the stimulated expression of g-type lysozyme, hepcidin, transferrin and metallothionein in both forms of the bacteria. There was no distinct expression pattern of the interleukin genes during bacterial exposure. This was in contrast to the chemokines where the expression of these genes in IEPCs was down-regulated upon exposure to the heat-inactivated probiotics. Although heat inactivation did not drastically affect the immunomodulatory capabilities of the probiotics, the live form elicited higher immune responses in the IEPCs in most cases. Conclusion: This study showed that bacterial viability was a contributing influence, but not a major limiting factor on the immune-related functions of the host-derived probiotics in vitro. Significance and Impact of the Study: GP21 and GP12 are beneficial hostderived bacteria and could be utilized as candidate probiotics in cod aquaculture.

Nutritional impacts on fish mucosa: immunostimulants, pre- and probiotics

“…The foundation of probiotic research is mainly based on a terrestrial perspective, on humans to be specific. This was also supported by several reports in fish that the viability of a number of probiotic candidates did not serve as a limiting factor of their beneficial actions Lazado and Caipang, 2014a;Lazado et al, 2010a;Pan et al, 2008;Salinas et al, 2006). In the early 2000s, Verschuere and colleagues provided a very lengthy yet encompassing definition that states, "probiotic is a live microbial adjunct which has a beneficial effect on the host by modifying the host-associated or ambient microbial community, by ensuring improved use of the feed and enhancing its nutritional value, by enhancing the host response towards diseases, or by improving the quality of its ambient environment" (Verschuere et al, 2000).…”

“…The immunomodulatory action following probiotic feeding is also reflected in the transcriptional profiles of antibacterial, cytokines, oxidative stress genes, to name a few, of the host especially in immune-related organs/ tissues (see reviews of Lazado and Caipang, 2014a, 2014b, 2014cNayak, 2010). Probiotics could also increase the number and improve the activities of many immune cells particularly erythrocytes, granulocytes, macrophages, and lymphocytes.…”

Innate Immune Responses of Skin Mucosa in Common Carp (Cyprinus Carpio) Fed a Diet Supplemented with Galactooligosaccharides

“…Second, it contains a large variety of antibacterial compounds, including proteins and enzymes, such as lysozyme and proteolytic enzymes, immunoglobulins, complement proteins, lectins, and C-reactive proteins [4,5]. Third, the dermis and epidermis contain a number of immunocompetent cells, including epithelial, mucus, club, and goblet cells, that account for the skin-associated lymphoid tissue (SALT) [6,7]. The major function of SALT is to locally recognize antigens in the skin and neutralize them with various types of innate and specific mechanisms [8].…”

Probiotics, immunostimulants, plant products and oral vaccines, and their role as feed supplements in the control of bacterial fish diseases

“…; Kazun & Kazun ; Newaj‐Fyzul et al . ; Lazado & Caipang ,b; ]. Generally in human and terrestrial animal medicine, probiotics centre on the lactic acid‐producing bacteria, presumptive Lactobacillus spp., which are associated with the production of yoghurts and fermented milk drinks (Fuller ; Lauzon et al .…”

“…Irianto & Austin ). Indeed, heat inactivation did not reduce immunomodulatory capability, that is expression of hepcidin, g‐type lysozyme, metallothionein and transferrin of Atlantic cod ( Gadus morhua ) derived intestinal epithelial cells, although live probiotic cells induced higher immune responses (Lazado & Caipang ,b). Some workers have identified key molecules that are responsible for immunomodulation (e.g.…”