Effect of suboptimal temperature on the regulation of endogenous antigen presentation in a rainbow trout hypodermal fibroblast cell line.
Rainbow trout (Oncorhynchus mykiss) face low environmental temperatures over winter months and during extreme low temperature events. Suboptimal temperatures are known to negatively impact the teleost immune system, although there is mixed evidence in rainbow trout as to the effect on the endogenous antigen processing and presentation pathway (EAPP). The EAPP is an important pathway for antiviral defense that involves the presentation of endogenous peptides on the cell surface for recognition by cytotoxic T cells. Using a rainbow trout hypodermal fibroblast (RTHDF) cell line as an in vitro model, we determined that constitutive EAPP transcript levels are not impaired at low temperature, but induction of up-regulation of these transcripts is delayed at the suboptimal temperature following exposure to poly(I:C) or viral haemorrhagic septicaemia virus IVb, which was still able to enter and replicate in the cell line at 4 °C, albeit with reduced efficiency. The delay in the induction of EAPP mRNA level up-regulation following poly(I:C) stimulation coincided with a delay in ifn1 transcript levels and secretion, which is important since interferon-stimulated response elements were identified in the promoter regions of the EAPP-specific members of the pathway, implying that IFN1 is involved in the regulation of these genes. Our results suggest that the ability of rainbow trout to mount an effective immune response to viral pathogens may be lessened at suboptimal temperatures.
['Abram|Quinn H|QH|', 'Rodriguez-Ramos|Tania|T|', 'Bols|Niels C|NC|', 'Katzenback|Barbara A|BA|', 'Dixon|Brian|B|']
D000064:Acclimatization D000818:Animals D017951:Antigen Presentation D002460:Cell Line D003080:Cold Temperature D005347:Fibroblasts D005393:Fish Diseases D029941:Fish Proteins D007369:Interferon Inducers D007370:Interferon Type I D029141:Novirhabdovirus D017686:Oncorhynchus mykiss D011070:Poly I-C D011401:Promoter Regions, Genetic D012333:RNA, Messenger D013602:T-Lymphocytes, Cytotoxic D015854:Up-Regulation
Temperature Endogenous antigen presentation Teleost IFN1 MH class I Tapasin