Combined application of autologous and xenogeneic heat shock proteins in vaccinotherapy of malignant tumors
I. Boliukh, G. Didenko, G. Potebnya
R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Kyiv, Ukraine
Introduction: The use of immunotropic substances of natural and synthetic origin, including heat shock proteins (HSP) is one of the successful strategies to improve the efficiency of existing tumor vaccines. Aim: Combined application of heat shock proteins derived from the chicken xenogeneic embryonictissue and from autologous tumor cells for creating effective antitumor vaccines. Methods: Protein extracts from embryonic and tumor tissue were obtained by protein ammonium sulphate salting-out. Column chromatography was used for HSP separations with molecular weight of 70 kDa. HSP were analyzed by western blot with anti-HSP-70 monoclonal antibody (Enzo, USA). Based on HSP fraction, a number of vaccines were constructed and their efficacy was analyzed in vivo in Balb/c and C57Bl/6 mice with transplantable Ehrlich carcinoma and Lewis lung carcinoma (3LL). All animals were divided on 6 groups consisting of 10 animals each. Antitumor effect of vaccines was evaluated by the dynamics of tumor growth, survival rate and antimetastatic effect. Results: Immunoblot test demonstrated antigenic homology of HSP-70 derived from embryonic chicken tissues and Ehrlich carcinoma. It was found that level of HSP-70 was 1.68 times higher in chicken embryonic tissues compared to Ehrlich carcinoma. Vaccines enriched with HSPS 70 were made from tumor samples and chicken embryonic tissues and their antitumor efficacy, manifested in inhibition of tumor growth (IG 24.35%) and the increase in life expectancy of experimental animals, has been shown. The purification of HSP-peptide complexes in tumor extracts and embryonic tissues was made and on their basis a number of vaccines has been developed, antitumor activity of which has been tested in the system in vivo on animals with transplantable 3LL. The effective vaccines stimulated cytotoxic activity of lymphocytes and macrophages (straight by 25% and antibody-dependent by 27%), increased serum cytotoxic activity and decreased the content of circulating immune complexes. Anticancer activity of vaccines was mainly reflected in the inhibition of metastasis. Conclusions: Combined use of xenogeneic and autologous HSP-peptide complexes for design of vaccines significantly increases their antitumor activity and immunomodulating effect compared with the vaccine prepared by the traditional technology.
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