The E(Spl) And CG7510Are Required For Regulating Of Drosophila Innate Immunity

The innate immune system is the first line of the multicellular organism against the various pathogens invading. The Notch signaling plays a significant role in maintaining the balance among cell proliferation, differentiation, apoptosis and development. To further investigate the function of Notch signaling pathway in Drosophila innate immunity, Drosophila mutants, E(spl) and Su(H), which are located in the downstream of Notch signaling pathway, were utilized to analyze the survival rate, in vivo phagocytosis and production of antimicrobial peptides after pathogen infections. In addition, the number of circulating plasmatocytes in third instar larvae of mutant and wild type flies was also measured. The results indicate that the E(spl) mutant showed lower survival rate, phagocytosis and the expression of AMP genes after pathogen infections. Furthermore, an abnormal increase in the number of plasmatocytes in E(spl) mutant larvae was also observed. Compared with E(spl) mutant, the mutant of Su(H) only showed sensitive to fungi, however, phagocytic ability of hemocytes was normal in fungi infection. At the same time, the expression of antimicrobial peptides was decreased in Su(H) mutant. These results show that the Notch pathway not only affects the growth and development of individuals, but also plays an important role in regulating innate immunity of Drosophila.CG7510is an orphan G protein-coupled receptors (GPCRs)which has more than40%homology with the mammalian G155. Increasing orphan GPCRs whose endogenous ligands and functions are still to be identifed have been discovered in recent years. It is obvious that orphan GPCRs might be the most important targets for innovating drugs. To study the function of CG7510in Drosophlia innate immunity, CG7510mutant was utilized to analyze the phagocytosis of larvae, location of the hemocytes actin and the transcriptional level of the CG7510. The results indicate that the CG7510mutant showed sensitive to gram-positive bacteria and fungi. In addition the formation of the hemocytes actin filopodia exhibited extensions defects.Furthermore, three new CG7510mutants was obtained by the method of P-element excision while the transcriptional level is lower than before. The above discoveries provided important theoretical basis and reference value for the future study the role of CG7510protein in innate immune.