Expression of immune genes in skin of channel catfish immunized with live theronts of Ichthyophthirius multifiliis

Abstract

The objective of this study was to evaluate differential expression of innate and adaptive immune genes, including immunoglobulin, immune cell receptor, cytokine, inflammatory protein, toll-like receptors (TLR) and recombination-activating gene (RAG) in skin from channel catfish, Ictalurus punctatus after immunization with live theronts of Ichthyophthirius multifiliis (Ich) by intraperitoneal injection. The immunized catfish showed significantly higher survival rate (95%) than those of mock-immunized control fish (0% survival) after the theront challenge. The gene expression of innate immune system, such as cytokines (IL-1β type a, IL-1β type b, IFN-γ, TGF1-β and TNF-α) and inflammatory proteins (NF-kB and iNOS 2), showed significant upregulation at day 1 (D1) post-immunization. Expression of TLR genes exhibited a rapid increase from hour 4 (h4) to D10 post-immunization. Genes of the adaptive response, such as the cell receptor MHC I, CD8 , CD4 and TCR-α, showed upregulation at D1, D6 and D10. The TCR-β expression increased rapidly at h4 and remained upregulated until D10. Immunoglobulin IgM upregulation was detected from h4 until D2 while IgD expression was increased from D1 until D10. Rapid upregulation of innate and adaptive immune genes in skin of catfish following live theront vaccination was demonstrated in this study ultimately resulting in significant protection against Ich infection.

Modulation of the innate immune responses in the striped snakehead murrel, <i>Channa striata</i> upon experimental infection with live and heat killed <i>Aeromonas hydrophila</i>

“…The gene for iNOS has been partially sequenced in both trout (Laing et al, 1999) and goldfish (Laing et al, 1996) and it is shown to be inducible after challenge in vivo with bacterial pathogen or in vitro with LPS. iNOS was also upregulated in channel catfish, Ictalurus punctatus after immunization with live theronts of Ichthyophthirius multifiliis (Moreira et al, 2017). However, NO production is not selectively targeted to microorganisms and has the potential to be toxic to host tissues in high concentrations.…”

Identification and Expression Profiling of Toll-Like Receptors of Brown Trout (Salmo trutta) during Proliferative Kidney Disease

“…In a brief experiment, TLRs were up-regulated (TLR8a1, TLR8a2, TLR8b1, TLR19, TLR20a, TLR22a1, and TLR22a2) and down-regulated (TLR3, TLR8b2, TLR9, TLR18, and TLR21) in the kidney of rainbow trout during natural PKD infection [34]. Moreover, intraperitoneal injection of live theront life stages of I. multifiliis modulated the expression of TLRs in channel catfish (Ictalurus punctatus) [35].…”

Quantitative trait loci (QTL) associated with resistance of rainbow trout Oncorhynchus mykiss against the parasitic ciliate Ichthyophthirius multifiliis

“…The parasite targets both wild and cultured fish but the huge economic impact of the protozoan is associated with mortality, morbidity, prevention and treatment in aquaculture facilities (Dickerson & Findly, 2017). The infected fish may mount a protective immune response (Bauer, 1953; Burkart, Clark, & Dickerson, 1990; Buschkiel, 1910; Dickerson & Clark, 1998; Goven, Dawe, & Gratzek, 1980; Hines & Spira, 1974; Moreira, Shoemaker, Zhang, & Xu, 2016; Sigh & Buchmann, 2001; Wang, Yu, Zhang, & Xu, 2019), but the experimental vaccines investigated so far (Burkart et al., 1990; He et al., 1997; Jørgensen et al, 2017; Ling, Sin, & Lam, 1993; Martins, Xu, Shoemaker, & Klesius, 2011; Wang, Clark, Noe, & Dickerson, 2002; Xu, Zhang, Shoemaker, & Beck, 2019) have not yet resulted in a marketable protective formulation. A number of chemotherapeutants have been successfully applied in the laboratory (Al‐Jubury et al., 2018; Picon‐Camacho, Marcos‐Lopez, & Shinn, 2012), but at farm level frequent usage of formalin, peracetic acid, sodium percarbonate and hydrogen peroxide remains the preferred control strategy (Heinecke & Buchmann, 2009; Meinelt et al., 2009; Rach, Gaikowski, & Ramsay, 2000).…”