Functional Studies Of Overexpression Of LIP In The Eukaryocyte

Lamprey,the representative of jawless vertebrates,was the oldest extant species with the adaptive immune system.Nowadays,studies about lamprey have tended to VLRs,however,which immune molecules involved in killing of exogenous cell in lamprey have not been reported.In previous study,a novel protein named lamprey immune protein(LIP)was identified from supraneural body tissues.The mechanism behind the phenomenon is unknown.In this study,LIP was overexpressed in HeLa cells and H293 T cells through pIRES2-AcGFP1-Nuc-LIP and pEGFP-N1-LIP vector.The function of eukaryotic recombinant LIP was explored using cell transfection,Western blot,Q-PCR,LDH,cell staining,cell cycle analysis,Microarray analysis and Immunofluorescence.Study results showed that eukaryotic recombinant LIP still exerts secretory capacity but only occur in the presence of stimulation.The expression of eukaryotic recombinant LIP also has no effect on organelles for H293 T cells but has remarkable effect on celluar redox state and organelles of HeLa cells in a dose-dependent manner.Cell cycle analysis confirmed G2M-phase cell cycle arrest.These results suggest that LIP inhibits tumor viability by cell-cycle arrest.Array data indicated that eukaryotic recombinant LIP can mainly cause IgA production in H293 T cells.The above results revealed that eukaryotic recombinant LIP is a multimer which located in cytoplasm.The possible mechanisms for LIP's targeting killing activity for tumour cells is G2 M arrest.In summary,this study provides a novel insight into the origins of lamprey immune system,and establishes the experiment foundation for further research on LIP's biological function.These observations suggest the presence of a novel protein in the lamprey and the possibility of new applications for the protein in the medical field.