Studies On Viral Immunotherapy Of H₂₂ Ascitic Tumor In Mice

Objective:tumor is the major dead cause for mankind disease at present. Many methods of treating tumor can relieve patient's suffering,such as operation, radiotherapy and chemotherapy. However, therapeutic efficacy of these methods is not well in lower healing rate, higher relapse rate and death rate. Viral therapy for tumor have provided a new way and gained some achievements in recent years,but it is not sure whether long-term effect is safe and it will take a long time to evaluate the final therapeutic effect of viral therapy. So it is necessary to understand the mechanism of action about viral therapy for tumor no matter in the effect aspect or in the mechanism of molecule. This thesis was Based on previous experiments and explore the immunological mechanism of viral immunotherapy with NDV and parainfluenza virus.Methods:40 inbred male and female mice bearing H22 tumor were divided into 4 groups equally and randomly at 10 mice per group: NS control group, CTX (cyclophosphamide) treatment group, Parainfluenza virus treatment group, NDV treatment group.24 hours after implanted with tumor, 4 groups were respectively given NS,CY,NDV,Parainfluenza virus by intraperitoneal injection on 1st,3rd ,5th,7th day. All the mice were killed on the 12th day to test level of IL-2 by collecting the serum of mice, and test the activity of natural killing(NK)cell,lymphocyte transformation rate and CD4~+/CD8~+ ratio by getting the cell of mice spleen. Moreover 40 inbred male and female mice bearing H22 tumor were divided into 4 groups in the same way and fed continuously to calculate survival time.Results:1. life span of every group: NDV treatment group and parainfluenza virus treatment group could prolong the life span of mice bearing tumors, the life span of NDV treatment group was 27.1d,longer than that of NS group(p<0.01), and survival rate 50%.The life span of parainfluenza virus treatment group was 33.3d,longer than that ofNS group(p<0.01),and survival rate 50%. the life span of CTX (cyclophosphamide) treatment group was also longer than NS group(p<0.05).2.the level of serum IL-2 in each group: the level of IL-2 in parainfluenza virus treatment group and NDV treatment group was higher than that of NS group and CTX (cyclophosphamide) treatment group obviously,and parainfluenza virus treatment group was better than NDV treatment group.3. the activity of natural killing(NK)cell,lymphocyte transformation rate and CD4~+/CD8~+ ratio in parainfluenza virus treatment group and NDV treatment group were stronger than that of NS group and CTX (cyclophosphamide) treatment group obviously,and parainfluenza virus treatment group was better than NDV treatment group. But the indexes in CTX (cyclophosphamide) treatment group was lower than that of NS group.4. morphology observation: tumour cells infected by virus were cellular necrosis in large-area,and the cellular membrane had viral particle and viral blastozoid.But tumour cells which were not infected by virus hadn't this result.Conclusion:The experiment showed NDV and parainfluenza virus have significant anti-tumor effect The mechanism is probably that the tumour cells infected by virus can induce and strengthen the tumour cells'antigenicity, and then form the Tumor Associated antigen (TAA),which stimulate host's immune system. (specific cellular immune response and humoral immune response) and improve the host's anti-tumor immunity.