Grass carp ( Ctenopharyngodon idellus ) invariant chain of the MHC class II chaperone protein associates with the class I molecule

Abstract

The invariant chain (Ii) is an important immune molecule, as it assists major histocompatibility complex (MHC) class II molecules to present antigenic peptides. The relationship between the Ii and MHC molecules in teleosts remains poorly understood. This study focused on the molecular structure of grass carp Ii (gIi), its organ distribution, correlations with gene transcription, and the association with MHC. gIi cDNA was cloned using designed degenerate primers and the rapid amplification of cDNA ends method (RACE). The gIi sequence was 92%-96% similar to that of other teleosts, but only 52%-67% similar to that of mammals, respectively. The gIi gene was distributed in all 12 organs examined by PCR. The gIi gene transcription levels were markedly higher in organs enriched with immune cells than in other organs (P < 0.01). Moreover, positive correlations were detected between transcription levels of the gIi and gMhcI or II genes in different organs (r = 8.415-8.523, P = 0.001). The gIi co-localized on endomembrane systems with either class I or II molecules in co-transfected cells observed by a laser confocal. Further testing confirmed that the gIi bound gMHCI and II molecules. Taken together, these results indicate that the gIi is associated with MHC class I and II molecules, suggesting homology of both MHC molecules.

VP4/VP56/VP35 Virus-like Particles Effectively Protect Grass Carp (Ctenopharyngodon idella) against GCRV-II Infection

“…MHC II molecules play a vital role during the onset of immune responses as they are responsible for presenting processed antigenic fragments to CD4+ T cells, and significantly influence humoral immunity [ 46 , 47 ]. A previous study reported an upregulation in MHC II mRNA expression levels in head kidneys following vaccination [ 20 ].…”

Ecological Risks Due to Immunotoxicological Effects on Aquatic Organisms

“…This may be a reason to use a single data using three trophic level species (i.e., algae, daphnia, and fish) for ecological risk ass ment although the tested species are not always representative of all aquatic ecosyste It appears that a simple concept of a ratio of PEC to PNEC may not be appropriate. logical impacts of pollution chemicals are depended on the susceptibility of the specie [19,62,[178][179][180]…”