Abstract

PERFORMANCE OF DNA OF SUSCEPTIBLE AND RESISTANT BIOMPHALARIA ALEXANDRINA SNAILS AS IMMUNOGENS IN SCHISTOSOMA MANSONI INFECTED MICE

Manal A. Hamed, Hanan F. Aly, Sanaa A. Ali, Nagy S. El-Rigal, Nadia S. Metwally, Samir H. Haggag, Maha Z. Rizk.

Abstract

The aim of the present work is to evaluate the role of DNA of either susceptible or resistant Biomphalaria alexandrina snails as a vaccine in Schistosoma mansoni infected mice. The evaluation was done through estimation of parasitological, biochemical and histopathological parameters in S. mansoni infected mice liver. The results revealed that malondialdehyde (MDA), xanthin oxidase (OX), glucose-6- phosphatase (G-6Pase), acid phosphatase (AP) and 5` nucleoprotein (5`Nu) are significantly increased in S. mansoni infected mice, while glutathione (GSH), vitamin C and E, glutathione reductase (GR), superoxide dismutase (SOD), catalase, succinate and lactate dehydrogenase (SDH & LDH) showed significant reduction after infection. Alternation of the energetic parameters (ATP, ADP, AMP, phosphate potentials, inorganic phosphate), amino acid fractions and LDH isoenzymes were also noticed. The work was extended to measure ova and worm counts as well as the histopathological picture of liver. Vaccination of S. mansoni infected mice with DNA of either susceptible or resistant snails, recorded amelioration levels of the selected parameters by variable degrees. In conclusion, we found that the DNA of susceptible snails was more effective in protecting against schistosomiasis. Further examinations of the DNA constituents must be performed to identify the specific target responsible for protection against infection.

Keywords: DNA; vaccine, Schsitosoma mansoni, susceptible; resistant; snails.