The expression of prostaglandins-related genes in erythrocytes of broiler chicken responds to thiram-induced tibial dyschondroplasia and recombinant glutathione-S-transferase A3 protein

Tibial dyschondroplasia (TD) is a type of bone deformity found in fast-growing chickens, which induce inflammatory responses. Prostaglandins (PGs) implicate in bone formation and bone resorption, associated with inflammation in an autocrine/paracrine manner. This study used qRT-PCR and immunohistochemistry analysis to identify the expression patterns of PG-related genes in the erythrocytes of broiler chickens and explore the effects of thiram-induced TD and the recombinant glutathione-S-transferase A3 (rGSTA3) protein on the expression of PG-related genes: GSTA3, cyclooxygenase 2 (COX-2), prostaglandin D2 synthase (PTGDS), prostaglandin E synthase (PTGES), prostaglandin E2 receptor (PTGER) 3, PTGER4 and prostaglandin reductase 1 (PTGR1). Interestingly, the results showed that these seven PG-related genes expression was identified in the erythrocytes of broiler chicken, and thiram-induced TD suppressed the expression of these PG-related genes in the initial stage of TD and promoted their expression in TD recovery. These findings demonstrated that the immunoregulatory function of erythrocytes can be inhibited in the early stage of TD and promoted in the recovery stage by modulating the expression of PG-related genes. Further, the rGSTA3 protein can modulate the expression of PG-related genes in erythrocytes and participate in the recovery of TD.

Construction of a novel display vector deriving from CS3 fimbriae of human enterotoxigenic Escherichia coli

Based on the prediction of the hydrophilicity, epitopes, secondary structure and flexibility of the CS3 subunit, a novel vector pCSX72 which permits the insertion of foreign epitopes into CS3 at the position of 72nd aa was constructed. Two epitopes, the VP1 of FMDV and a ten-peptides epitope of C-myc, were displayed with it respectively. Compared with the two previously-constructed vectors, the vector pCSX72 expressed the hybrid fimbriae in higher level. Mice produced dual immune response against the CS3 and the inserted epitopes when they were immunized by injecting the live recombinant bacteria intraperitoneally.

[Expression of C3 epitope of poliovirus and a ten-peptides epitope of C-myc on the surface of recombinant bacteria]

To confirm the possibility of pCSB136 and pCSX72 as vectors for displaying heterologous epitopes, the gene fragments coding for C3 epitope of poliovirus and a ten-peptides epitope of C-myc were synthesized and inserted into pCSB136 and pCSX72 respectively. The recombinants were screened by whole-strain PCR. The expression of recombinant proteins were detected by whole-cell ELISA and electronic microscopy. The results indicated the recombinant proteins were expressed as hybrid fimbriae, and the antigenicity of both CS3 and inserted epitopes kept. All results above showed vectors pCSB136 and pCSX72 could be used to display the foreign epitopes.