Identification of interferon-γ-inducible-lysosomal thiol reductase (GILT) gene from Mefugu (Takifugu obscures) and its immune response to LPS challenge

• An GILT homologue has been cloned and identified from Mefugu.
• The expression pattern of GILT gene is investigated in various tissues.
• The mGILT expression is obviously up-regulated in spleen and kidney after immunization with LPS.
• We also describe the expression and bioactivity analysis of GILT protein.

Interferon-γ-inducible-lysosomal thiol reductase (GILT) plays a key role in the processing and presentation of MHC class II-restricted antigen (Ag) by catalyzing disulfide bond reduction. In this study, a Mefugu cDNA (ToGILT) encodes a deduced protein of 242 amino acids with a putative molecular weight of 28.6 kDa. It contains typical features of GILT proteins including the signature sequence CQHGX2ECX2NX4C, CXXC motif and other five cysteines. Genomic analysis revealed that ToGILT gene exhibited a similar exon–intron organization to human and mouse GILT. Phylogenetic analysis showed that ToGILT derived from a common ancestor with other vertebrate GILT proteins. The ToGILT mRNA was expressed in a tissue-specific manner and obviously up-regulated in spleen and kidney after LPS induction. These results suggest that ToGILT may be involved in the immune response to bacteria challenge in Takifugu obscurus.