| Avian leukosis virus subgroup J(ALV-J)was first reported as a new subgroup of ALV by Payne in 1991 in the United Kingdom,induced avian myelcytomatosis (ML) in meat-type chickens.Subgroup J avian leukosis (ALV-J) is a kind of tumors of horizontal and vertical transmission disease. This kind of disease mainly occurs in Broiler breeder chickens. Since first time isolated ALV-J, the disease has spread rapidly around the world. Subgroup J avian leukosis (ALV-J) is endogenous recombinate exogenous ALV. Because of the diversity, the specificity of ALV-J virus and the lesion complexity caused by ALV-J, So far there is no the best way to prevent ALV-J, and no effective solutions, drugs and vaccines to control ALV-J infection, since the group has been found to cause significant economic losses. ALV - J in addition to the breeding cause huge losses, but also directly causing the body serious immunosuppression, and we further analyzed the interaction of ALV-J with Exosomes. Therefore, the immunosuppression mechanism of ALV-J caused and the research of related factors have important influence in further research of prevention and control of ALV-J.In 1987, Johnstone found some vesicles secreted by Reticulocyte and he termed them Exosome. After that, more and more reseachers have done the related researches, they found lots of cells such as blood cell, epithelial cell, neurocyte, tumor cell(include melanoma cell, lung cancer cell, celiothelioma cell, breast cancer cell, ovarian cancer cell, leukemic cell and so on)can secret exsome. In recent years, the study found that there are mang relation between the Exosomes secretion and retroviruses budding, for example human cytomegalo virus (HCMV) protein US28 mainly exists in MVB, through HCMV virus assembly and virus coated grouped together. HIV - 1 budded dependent Tsg101,a very important kind of protein in MVB formation process. Retroviruses to go out on the serosal MVB way to shoot with within cytoplasm,as budding membrane parcel cytoplasmic retraction,such retroviruses by modified MVB seemed esicles (such as Exosome within,likely as by MVB and serous fusion released to the extracellular environment. Hence, we assume that the virus infected cells secrete Exosome might carry some of the virus in signal transduction protein, the transmission of the virus to cause the cells to composition, the loss of viruses recognise, thus make the virus to be able smoothly in replicate and spread.This study use ALV-J for model to study the virus infected cells secrete Exosome in the role of ALV-J immunosuppression. We isolated Exosomes from the normal DF–1 cells and ALV-J infection DF–1 cells culture medium by fractional centrifugation and density gradient centrifugation. Their morphology and biological characteristics were identified by Electron microscope and Western blot analysis. The results showed that density of fractions containing Exosomes was between 30% and 45% Sucrose gradient belts. The Exosomes were 30-100 nm in size and cup-shaped morphology, which are similar to the previous report for Exosomes released from other cells. Our data indicated that DF-1 cell can secrete Exosomes. Releases two cells were extracted by supernatant fluid BCA proteins found ALV-J quantitative Exosome concentration for normal, infection Exosome concentration of 63 times.The relationship between released ALV-J and secreted Exosomes were analyzed by Western blotting. The results showed that the characterizations of vesicles bearing ALV-J isolated from ALV- J infection DF–1 cells culture medium were reminiscent of Exosomes, Hsp70 etc mark protein exists in the extraction of Exosomes. With ALV-J polyclonal antibody detected Exosome extracted from ALV- J infect DF-1 cells supernatant fluid could found a positive strip,molecular size for 70kD around, but there is no positive strip in Exosome extracted from normal DF-1 cells supernatant fluid, showing ALV -J infect DF-1 cells secrete the Exosome carry the virus protein. ISU peptide could conpand normal DF-1 cells to prevent viruses replicate and reduce the intracellular virus content, with ALV- J polyclonal antibody detected Exosome extracted from normal DF–1 cells and ALV-J infection DF–1 cells could found a positive strip, molecular size for 70kD around, showing ALV-J infect DF-1 cells secrete the Exosome carry the substance combined with the ISU peptide. This substance is normal DF–1 cells secreted, ALV-J infected cells does not affect its formation. These results demonstrated that ALV-J present in extracellular space might be externalized through secreted Exosomes from ALV-J infection DF–1 cells, so we can speculate that Exosome could carry ALV-J and play an important role in the spread process, these put forward new ideas for us to the prevention and control of ALV-J. |
