The Study Of Tumor Antigen Activity Of Zheng's Plant Protein

Objective: Tumor has become one of the fatal diseases for mankind. We are working for trying to find the cause of tumor and the effective measure of treatment all the time. Tumor cell is transform from normal cell. Although the immunological system in the body has the faction of immue surveillance and take immuneresponse to the tumor cell, even a lot of primary tumor in the host can take place, then tend to growth,metastasis and recur. The poor immunogenicity is the main reason of sneaking through. We should enhance the immunogenicity of tumor cells. And the focus of tumor immunotherapy is tumor antigen. How to find high tumor-specific antigen, break the immunotolerance and produce high effective vaccine has become the focus of immunotherapy. By the theory of biologic evolution, different organisms exist syngenes, when the nature evolves from the lower grade to the higher grade. And the father is the relation between the two organisms, the stronger the immunogennicity is. We used Zheng's plant protein(ZPP)－a kind of 50 KDa glycoprotein extracted from a lower plant, between species to elevate immunogenicity and overcome self-immune tolerance to tumor cells in the body.Methods: 1.Chloramine－T which is a mild oxidizer can oxide I- to I+. The latter can combine with tyrosine. Through this way, we obtained antibody of the vegetable protein labeled by 131I. We injected the antibody into Lewis mice suffered from Lung Cancer, and radioactivity of different tissues was measured in different time(12h,24h,48h,72h) after injecting and biological distribution of this antibody was observed in the mouse's organs to find if it could combine with the tumor cell significantly. 2.Antigen has antigencity. It can combine with it's antibody specifically. Using marked antibody trace antigen can demonstrate its orientation and distribution in the tissue and cell. So, we use Anti-ZPP as primary antibody, studied its immunohistochemical expression in human malignant tumor samples(esophageal carcinoma, lung cancer ,colonic cancer and cardiac carcinoma), matched tumor-side tissue and normal esophageal mucosa to demonstrate ZPP has human tumor antigen-like structure. 3.colloidal gold can combine with antigen in alkali environment. We use normal goat sera(1:50) as blocking antigen, colloidal gold labled Anti-ZPP as secondary antibody, study its orientation in esophageal carcinoma and tumor-said tissue through immunogold staining technique.Results: 1.The antibody of the vegetable protein had a different affinity to the mouse's organs and tumor tissues．Radioactivity of tumor tissue was far higher thanthat of the other's tissues(heart,liver,spleen,kidney,muscle). The ％ID／g of tumor tissue was 3.08±0.29,2.85 ±0.42,2.97±0.38 and 2.76±0.45 respectively in 12h,24h,48h and 72h after injected the antibody. This results indicated that Anti-ZPP could combine with tumor cell specifically. 2.The staining pattern can be classified into three grades. Grade Ⅰ, in normal esophageal mucosa,colonic cancer and its tumor-side tissue no detectable Anti-ZPP were found. Grade Ⅱ, in esophageal carcinoma,lung cancer, and cardiac carcinoma, the expression of Anti-ZPP was faint. Grade Ⅲ, the expression of tumor-side tissue of esophageal carcinoma,lung cancer, and cardiac carcinoma is high. There was a significant difference between grade Ⅱ and grade Ⅲ. Positive cells were stained with cytoplasm. Contrarily, the expression of serous gland cells is higher than mucous gland cells. In positive tumor samples, the expression of well-differentiated was higher than that of poorly-differentiated. 3.In both esophageal carcinoma tissue and its tumor-side tissue, colloidal gold only can be seen around mitochondria, rough surface endoplasmic reticulum and the nucleus.Conclusion: Zheng's plant protein has characteristics of tumor common antigen. Its structure may be similar with human tumor antigen. This activity can be used clinical for tumor early diagnosis and its antibody may be supposed to be used for immunolog...