Immunosuppressive effect of naked DNA vaccine targeting tissue factor by intrasplenic inoculation on colorectal cancer / 中国病理生理杂志

ABSTRACT

AIM: To investigate the expression of objective gene and the immunosuppressive effect of naked DNA vaccine pγ1.Ig H.SPTT targeting tissue factor by intrasplenic inoculation on colorectal cancer ( CRC) .METH-ODS:A special naked DNA vaccine which carried the SPTT peptides and immunoglobulin H chain gene ( named pγ1.Ig H.SPTT DNA plasmid ) was constructed by molecular biological techniques .After a single injection of this plasmid into the spleen, the concentrations of transgene product SPTT-Ig H in the peripheral blood at different time points were detected by ELISA, and the plasmid transfection efficiency and characteristics were analysis by PCR and Southern blotting .The immu-nologic effect of the plasmid on the CRC was observed in the mice .RESULTS:The strongest expression of SPTT-Ig H was observed during the 4th week after a single injection of the plasmid , which began to decline at the 12th week and disap-peared at the 16th week.The concentration of SPTT-Ig H in the peripheral blood at the 2nd week after transfection of plas-mid was 7.2 μg/L, then increased gradually , and reached a peak of 13.11μg/L at the 8th week.The plasmid-transcrip-tional gene was only expressed in the spleen , and was not detected in the lymph nodes , bone marrow, liver, kidney, and other organisms.Transfection of pγ1.Ig H.SPTT into the spleen had inhibitory effects on colorectal cancer as compared with control group .CONCLUSION:Naked DNA vaccine pγ1.Ig H.SPTT stimulates the immune response for protecting the body against colorectal cancer , which is a safe and effective method for CRC immunotherapy .