The Killing Effect On Liver Cancer Cells By Mouse Macrophages Stimulated By Newcastle Disease Virus 7793 Strain

Background and Objective:Newcastle disease virus, (Newcastle disease virus, NDV) belongs to Avulavirus genera of the Paramyxoviridae family. It is highly pathogenic to birds, but to human it can infect and kill the tumor cells and in rare cases it damages normal cells after infection. Lysis of tumor cells with Newcastle disease virus have been a hot spots in the tumor biotherapy. For the past sixty years,many reports shown that NDV can treat many kinds of cancers. Following the surgical therapy, chemotherapy and radiotherapy, cancer treatment with NDV has become one of new biological methods. Nowadays, researchers and clinical doctors pay more and more attention to NDV application in cancer therapy.In order to find the mechanism of NDV strain for triggering the nonspecific immunity to tumor-bearing body, we chose NDV7793 to stimulate the BALB/C mouse macrophages, then used the ELISA to determine the concentration of TNF-αand TRAIL after NDV stimulation. We also used RT-PCR to assay the level of TRAIL mRNA after NDV stimulation. Then we coincubated mouse activated macrophages with Novikoff cells, after a stretch we checked the LDH of the cell culture supernatant to assay the killing value after NDV stimulation. Materials and Methods:One NDV strain isolated in Jiangxi Poyang Lake (NDV 7793) was involved in the research. The NDV was inoculated in chick embryo for virus amplification, After 48 hours, the allantoic fluid containing viruses was harvested and tested haemagglutianation (HA) titer of virus, when HA titer≥1:1024, purified the viruses through high speed centrifugation, then stored at -80℃. Vero-E6 and Novikoff cells were grown according to recommendation.In vitro, we took the mouse peritoneallavage to collect macrophages. Then through the adherent culture to screen the cells we need. Collected the culture after NDV stimulation and then measured the concentration of TNF-αand TRAIL. At the same time, we used RT-PCR to detect the level of TRAIL mRNA after NDV stimulation. At last, mixed the mouse activated macrophages with Novikoff cells and coincubated for 12h, then collected the supernatant to measure the LDH.In vivo, NDV 7793 stimulated the mouse through the peritoneal injection. After five days, we killed the mouse and collected the macrophages. The measuring items were performed as in vitro. Results:In vitro, the macrophages stimulated with NDV 7793 had been activated, and after being stimulated for 12h, the level of TNF-αand TRAIL in culture supernatant increased. TRAIL mRNA of the macrophages after NDV stimulation also increased. In the mean time, we also found that the killing ability of macrophage to Novikoff cells after NDV stimulation increased.In vivo, the macrophages of the mouse injected by NDV7793 had been activated, and more TRAIL mRNA expressed within cells. The concentration level of TNF-αand TRAIL in blood also increased. More over, improved LDH in the coincubated cell supernatant after NDV stimulation indicated that the killing ability of macrophage to Novikoff cells increased.Conclusions:1. The NDV 7793 can activate the macrophages of the mouse.2. The killing effect on liver cancer cells of the mouse macrophages is enhanced by NDV stimulation. And it is possible that TRAIL involves in this enhanced killing effect.