The Distribution And Safety Studies Of Follicular Inhibin DNA Vaccine PXAIS On Mice

The pXAIS was a previously constructed DNA vaccine against follicostatin in our laboratory,and the plasmid that delivered by attenuated Salmonella C500 from balanced lethal system.With the development of DNA vaccines,many researchers are interedted in distribution and biosafty of DNA vaccines.This research provided scientific data for the applying ofpXAIS DNA vaccine.The results were shown as follows:1.The distribution of living bacteria and hematotoxicity testOne hundred of 37-day-old female mice were randomly divided into four groups,(1) Experimental group:the mice were immunized by intragastric administration with pXAIS vaccine,and the dose is 200μL(2×10¹⁰CFU/ml).(2) Control group of C500:the mice were immunized by ntragastric administration with C500 and the dose is 200μL(2×10¹⁰CFU/ml).(3) Control group of PBS:the mice were immunized by ntragastric administration with PBS and the dose is 200μL.(4) Blank control group:the mice of this group didn't deal with nothing.All mice were just immunized once.The toxicity was observed from beginning of the test to post-discontinuation within 14 days,the distribution of bacteria vector was detected in the mice body and the hematotoxicity were detected which index including of hematology and biochemics.The toxicity was observed from beginning of the test to post-discontinuation within 14 days.The result was demonstrated that there was no obvious alteration in body weigh, appetite and faeces of mice compared with control group.The recombinant Salmonella strain couldn't be found on 8h post-inoculation,but could proliferate in different organs on 1-4 days post-inoculation and numbers of live bacteria in some organs were counted.And the live bacteria in six kinds of organs were found on 5 days post-inoculation,and then the numbers of live bacteria decreased.There was no bacterium present in above organs on 14 days post-inoculation.Clinical biochemical indicator was fluctuated within normal limits.The toxic reaction related to pXAIS DNA vaccine didn't detect.2.Safty test of repeated doseTwo hundreds of 37-day-old female mice were randomly divided into two control groups and three different kinds of dose groups.The three different dose was 2×10⁸CFU/ml,2×10⁹CFU/ml and 2×10¹⁰CFU/ml.The two control groups were immunized with PBS and C500.The mice were were immunized by intragastric administration for three times,and the intermission was two weeks,the tissue distribution of the plasmid and the possibility of integration into the porcine genome were detected,at the same time histopathological changes and the organs weight were detected.No significant differences were observed between the vaccination and control groups in the examination of hematology,mortality and clinical signs were not observed either. In contrast to the control group,there was no significant difference among the tested groups on organ weight.The result to assess histological changes:The histological lesions were found in liver of immunized mice,including leukomonocytes in liver,but the control group had this condition,too.So the lesions were no contact with the vaccine.No significant changes were detected in other organs or in any collected tissues of control groups and tested groups.The chromosomal intergration with plasmid was tested by PCR,and the result was conformed that intergration couldn't be detected in the female mouse and her offspring,that is say the probability that DNA integrated into the cytogene of host cell.To sum up,the results of a preliminary study from the whole body,the system,the organs,the molecular and the gene level showed that the construction of our own pAXIS DNA vaccine is safe in mice.