A DNA vaccine containing PPE68 induces humoral response in cattle.

摘要

In this study, we used an approach known to stimulate Th1 immune responses, DNA vaccination, to produce PPE68, a RD1 antigen absent in BCG. We found that after four intramuscular doses (1/every 2 weeks), the production of IFN- gamma by vaccinated cattle was not different with respect to saline- or empty vector-vaccinated animals, but sera from animals receiving PPE68 DNA vaccine was able to detect, in M. bovis BCG Pasteur whole-cell extracts, two protein bands between 37 and 50 KDa (PPE68 expected size of 37 KDa), which were absent in saline- or empty-vector vaccinated animals. This, therefore, suggested a humoral response towards a protein that might cross-react with PPE68 was raised in pVAX1-PPE68 vaccinated cattle.