ABSTRACT
In the present study, for the first time, we released and assembled the particles of three major structural proteins of velogenic NDV (M, HN, and F glycoproteins) as a NDV-VLPs. The ElISA result of the cytokines of splenocyte suspension cells showed that IL2, IL10, TNF-α, and IFN- Ë titers were significantly higher (p ≤ 0.05) in mice that were immunized only with NDV-VLPs three times with a 10-day interval, in comparison to those that were immunized with NDV-VLPs twice in a 10-day interval and received a B1 live vaccine boost on the third interval. Flow cytometry results showed that CD8 + titers in the group that only received NDV-VLP was higher than other group. However, serum ELISA results did not show a significantly (p ≥ 0.05) higher NDV antibody titer in NDV-VLPs immunized mice compared to the boosted group. Besides, HI results of SPF chickens vaccinated with NDV-VLPs and boosted with B1 live vaccine were significantly (p ≤ 0.05) higher than those that only received NDV-VLPs. Interestingly, after challenging with NDV sub-genotype VII, all the chickens that were solely vaccinated with NDV-VLPs remained alive (six out of six), whereas two out of six chickens that were vaccinated with NDV-VLPs and also received the B1 live vaccine boost died. In conclusion, our results strongly indicated that the T-cell immune response in an NDV host is more important than the B-cell response. Also, the results of the present study revealed that to completely protect chickens against velogenic NDV strains, a vaccine comprising specific epitopes of velogenic strain is needed.
ABSTRACT
Different living organisms are used as applicable bioindicators to determine heavy metal pollutions. Recent studies have shown that helminths parasites can be used as efficient environmental sentinels. This study aimed to evaluate Fasciola hepatica and Dicrocoelium dendriticum as bioaccumulators of lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu). For this work. A total of 50 samples (F. hepatica, D. dendriticum, and livers from the infected and uninfected sheep, each of 10 samples) were collected from sheep slaughtered in Tabriz abattoir. One gram of each sample was incinerated and analyzed by Flame Atomic Absorption Spectrometry. The analysis of samples showed that Pb, Cr and Cu values in F. hepatica were higher than those in D. dendriticum, but only the differences of Pb and Cu were significant. The values of heavy metals in F. hepatica were significantly higher than those in the infected livers (except for Cd), while in D. dendriticum, Cr and Cd were only higher. Based on metal levels in livers, it was found that bioconcentration factors (BCFs) of Cr, Pb and Cu for F. hepatica were much more than one, and BCFs of these three metals between two flukes were statistically significant. This study indicated that F. hepatica had a higher bioindicator potential than D. dendriticum to evaluate environmental pollutants by some metals.
