Antimicrobial response is increased in the testis of European sea bass, but not in gilthead seabream, upon nodavirus infection

Characterization of the IFN pathway in the teleost fish gonad against vertically transmitted viral nervous necrosis virus

“…However, in the gilthead sea bream, specimens which overcome the infection, the tight regulation of the gonad immune response could avoid germ cell damage, but at the same time allow the transmission of the virus through the gonad fluids and gametes. This hypothesis is supported by the fact that when other immune molecules such as antimicrobial peptides are studied, their expression patterns in the brain and gonad of VNNV-infected sea bass are similar (Valero et al, 2015). However, the antiviral immune response in the reproductive organs deserved further investigation, as in immature rainbow trout (Oncorhynchus mykiss) females, VHSV infection provoked an upregulation of type I IFN genes (ifn1, ifn2, ifn3/4, mx1, mx2 and mx3) in the ovary (Chaves-Pozo et al, 2010).…”

“…Concretely, although we failed to detect any viral gene expression by conventional and real-time qPCR, we have already shown that VNNV is able to replicate in the gonad of gilt-head sea bream and European sea bass by in situ PCR, immunohistochemistry and viral recovery using cell culture (Valero et al, 2014). In addition, and most strikingly, the activity of antimicrobial peptides, and their transcription, was greatly upregulated in the gonad of VNNV-infected sea bass specimens, but this was not the case in the sea bass brain and in the gonad of sea bream specimens (Valero et al, 2015). These data point to the importance of gonad immunity in VNNV establishment and dissemination, and prompted us to carry out this study.…”

Immune-Endocrine Interactions in the Fish Gonad during Infection: An Open Door to Vertical Transmission

“…Some of them have been described as regulating molecules of the innate immune response, but most of them seem to act without triggering an inflammatory response [74]. In the mammalian and avian reproductive tissues, several types of AMPs have been described, as in fish [75][76][77][78][79]. Thus, as described previously, two hepcidins have been detected in the testis of mudskipper, one of them (hepcidin-2) being regulated by gonadotrophins and stimulated by LPS [56].…”

“…It was found that the immune response triggered by NNV in the testis of both species is completely different both in brain, the target tissue for NNV, and immune tissues themselves. Thus, the testis of the European sea bass showed strong up-regulation of genes coding for pro-inflammatory cytokines, immunoglobulin M, type I IFN pathway molecules (including sensors, intermediaries and effectors), AMPs (including defensin, hepcidin, lysozyme or histones), and acute-phase proteins such as haptoglobin, while their transcription was mainly unaltered or down-regulated in the brain [75,113,[134][135][136]. Furthermore, some antimicrobial peptides seem to be locally regulated by the gonad since their pattern of expression coincides after in vivo and in vitro infection with NNV [75].…”

“…Thus, the testis of the European sea bass showed strong up-regulation of genes coding for pro-inflammatory cytokines, immunoglobulin M, type I IFN pathway molecules (including sensors, intermediaries and effectors), AMPs (including defensin, hepcidin, lysozyme or histones), and acute-phase proteins such as haptoglobin, while their transcription was mainly unaltered or down-regulated in the brain [75,113,[134][135][136]. Furthermore, some antimicrobial peptides seem to be locally regulated by the gonad since their pattern of expression coincides after in vivo and in vitro infection with NNV [75]. By contrast, in the gilthead seabream most immune-related genes were down-regulated in testis upon in vivo and in vitro infection but greatly up-regulated in the brain [75,113,134,135].…”