A non-coding interspecies conserved motif of the Immune System Released Activating Agent induced potential immunoregularory effects (P1071)

Abstract

Abstract We have recently discovered ISRAA as a novel nervous system-induced factor inducing immune responses in mouse spleen. ISRAA gene was cloned and its sequence was mapped to chromosome 14. Herein, in silico simulation approaches were used to identify the human ISRAA. The data showed that ISRAA gene constitutes a sequence within human chromosome 10 in Zmiz1 gene intron with no similarity between coding sequences. Even though, this mouse protein showed potential biological activities on human cells. Titration of mouse ISRAA on human cells depicted dose-dependent effects since 5μg exhibited positive apoptosis while 50pg revealed significant proliferation (p<0.0005) and increased IFN-γ production. Cells from immunosupressed patients did not proliferate after PHA stimulation, but demonstrated significant proliferation to 50 pg ISRAA (p<0.005). A concentration of 500ng ISRAA showed cytotoxic effects on two sets of tumor cell lines, but not on healthy cells. Furthermore, a predicted active site of ISRAA gene was constructed and a mutant ISRAA lacking this motif was produced and tested. This motif was found to have 72% similarity with the interspecies conserved signal peptide motif of TNFR1. Mutant ISRAA showed no biological activity compared to its wild type. Thus, functional interspecies non-coding conserved domains exist, and ISRAA effects on immunocompromised cells and tumor cell lines can be explored in future therapies to treat immunosuppressive and cancer disorders.