Humoral immune responses and protective efficacy by various doses of Salmonella ghost cells carrying enterotoxigenic Escherichia coli (ETEC) fimbrial antigens for protection against piglet colibacillosis were studied. All groups were orally primed and boosted at 11 and 14 wk of pregnancy, respectively. Group A sows were inoculated with phosphate-buffered saline (PBS), and groups B, C, and D sows were immunized with 2 × 10(9) 2 × 10(10), and 2 × 10(11) ghost cells, respectively. Serum immunoglobulin (Ig)G, and colostrum (Ig)G and (Ig)A levels of groups C and D sows were significantly higher than those of group A sows. In addition, serum (Ig)G and (Ig)A levels in group C and D piglets were significantly increased compared to those of group A piglets. After challenge with wild-type ETEC, diarrhea and mortality were not observed in group C and D piglets, while diarrhea was observed in 88.9% and 58.8% of groups A and B piglets, respectively, and 16.7% mortality was observed in group A piglets. These findings indicate that oral immunization of sows with 2 × 1010 or 1011 ghost cells can effectively protect their offspring from colibacillosis.

The objective of this study was to assess the minimum dose, antigen content, and immunization duration of a trivalent vaccine containing inactivated Haemophilus parasuis serovars 4, 5, and 12 and the Montanide GEL 01 PR adjuvant in piglets and pregnant sows. Our results demonstrated that the minimum vaccine dose was 2 mL per pig and the optimal antigen content 2.0 × 10(9), 1.0 × 10(9), and 1.0 × 10(9) colony-forming units/mL of serovars 4, 5, and 12, respectively. The vaccine provided effective protection 14 d after the 2nd vaccination, and the period of immune protection was 180 d (6 mo) after the 2nd vaccination. Maternal antibodies provided early protection for the piglets, and vaccinating the sows before farrowing helped to control disease and protected the piglets during lactation; the piglets were protected during the finishing period by being vaccinated during lactation. Our findings provide a basis for developing a commercial trivalent vaccine of inactivated H. parasuis serovars 4, 5, and 12 against Glässer’s disease.

OBJECTIVE To compare gene expression patterns of T cells in porcine colostrum and peripheral blood. ANIMALS 10 multiparous sows. PROCEDURES Cytotoxic and CD4-CD8 double-positive T cells were separated from porcine colostrum and peripheral blood. Total RNA was extracted. The cDNA prepared from RNA was amplified, labeled, fragmented, and competitively hybridized to DNA microarray slides. The DNA microarray data were validated by use of a real-time reverse-transcription PCR assay, and expression of the genes FOS, NFKBI, IFNG, CXCR6, CCR5, ITGB2, CCR7, and SELL was assessed. Finally, DNA microarray data were validated at the protein level by use of flow cytometry via expression of c-Fos and integrin β-2. RESULTS Evaluation of gene expression profiles indicated that in contrast to results for peripheral blood, numerous cell-signaling pathways might be activated in colostrum. Profile analysis also revealed that FOS and NFKBI (genes of transcription factors) were involved in most cell-signaling pathways and that expression of these genes was significantly higher in colostral T cells than in peripheral blood T cells. Furthermore, CCR7 and SELL (genes of T-cell differentiation markers) in colostral T cells had expression patterns extremely similar to those found in effector or effector memory T cells. CONCLUSIONS AND CLINICAL RELEVANCE All or most of the T cells in colostrum had an effector-like phenotype and thus were more activated than those in peripheral blood. This gene expression profile would enable T cells to migrate to mammary glands, be secreted in colostrum, and likely contribute to passive immunity provided by sows to newborn pigs.