Injection of pGRF Gene Plasmid May Relieve Growth Depression Induced by Lipopolysaccharide in Weanling Piglets

The purpose of this study was to evaluate the effect and the potential mechanism of administering a pGRF gene plasmid on the growth and immunological function of weanling piglets subjected to immune-stress.Eighteen weanling(Duroc×Landrace×Large White) piglets aged 35 d±2 d and initial BW of 7.86 kg±0.59 kg were randomly assigned to three treatments according to gender and BW by using a single factor design.The three treatments were injections of a pGRF gene plasmid,pGRF gene plasmid followed by challenge with lipopolysaccharide(LPS),and LPS to piglets not receiving the plasmid.Each treatment group consisted of six piglets.The results were as follows:piglets in the pGRF gene plasmid plus LPS treatment had a better growth performance than those only receiving LPS(P【0.05), and F/G of piglets in the pGRF gene plasmid plus LPS group were very slightly lower(P】0.05) than those in the LPS group;serum levels of IGF-1 in the pGRF gene plasmid plus LPS group were significantly higher than those in the LPS group(P【0.05 or P【0.01);serum levels of IgG in the pGRF gene plasmid plus LPS group were higher than those in the LPS group(P【0.05);serum levels of IL-1 and IL-6 in the pGRF gene plasmid plus LPS group were significantly lower than those in the LPS group(P【0.05 or P【0.01).

Characterization of the Bombyx mori Cecropin A 1 promoter regulated by IMD pathway

Cecropin A1 （CeeA1） promoter from Bombyx mori was cloned and character- ized to provide insight into the transcriptional control of this antimicrobial peptide gene upon immune challenges. Reporter gene assays demonstrated that both Escherichia coli and lipopolysaccharide could induce expression in BmE cells but B. bombyseptieus or peptidoglycan failed, and the induction pattern of the reporter gene was coincident with the endogenous CecAl. Analysis of deletion and mutation constructs revealed that the regulatory region was the κB motif located between -176 and -166, and no other pre- dicted elements on CecAl promoter affected its inducibility. Insertion of additional κB motifs increased the activity of CecAl promoter. Furthermore, binding of Relish to lob motif was confirmed by electrophoretic mobility shift assay. These findings indicate the regulatory mechanism of CecAl expression in IMD pathway and suggest an approach of engineering antimicrobial peptide promoter with enhanced activities that may lead to broad applications.

Congenital infection of rabbits with Schistosoma japonicum and protective immunity of offspring

Background Recently congenital infection with Schistosoma japonicum (S. japonicum) has been domonstrated in pigs, rabbits, mice and dogs. We explored the rabbit as an animal model for the congenital infection of schistosomiasis japonica and assessed the effect of a congenital S. japonicum infection on the resistance of rabbit kittens to a postnatal challenge infection.Methods Sixteen pregnant New Zealand white rabbits were infected with a single dose of S. japonicum cercariae. The exposed animals were divided into three groups according to the gestation age at the time of infection. Diagnosis of prenatally acquired S. japonicum infection in the rabbit kittens was primarily based on serological tests in combination with parasitological and histopathological findings. Congenitally infected kittens were challenged percutaneously with 100 S. japonicum cercariae to assess the effect of a congenital S. japonicum infection on kitten resistance to a postnatal challenge infection.Results The overall prevalence of congenital infection in offspring of infected mothers was 20% (12/60). The congenital infection rate in group L (late gestation) was much higher than in group E (early gestation) and group M (mid-gestation) (P<0.05). After a postnatal challenge infection, prenatally infected kittens had a 54.66% worm reduction rate, 41.45% egg reduction rate, and 51.76% granuloma size reduction rate compared to nave kittens.Conclusions This study demonstrates the possibility of congenital infection of S. japonicum in rabbits and the resistance of congenitally infected kittens to a postnatal challenge infection. These results have important implications not only for epidemiological investigations, but also in designing government control programs for schistosomiasis.