New Hope for Rotavirus Control

CHINA - Working in mice, researchers from the Northeast Agricultural University have produced results that indicate a promising new method for the control or rotavirus infection.

30 December 2009

3 minute read

Asia

Using mice as a model, Qiao and colleagues from the Northeast Agricultural University in Harbin have found a way to induce mucosal and antibody responses to rotaviruses. Their work has been published in BMC Microbiology.

The researchers explain that porcine rotavirus infection is a significant cause of morbidity and mortality in the swine industry necessitating the development of effective vaccines for the prevention of infection. Immune responses associated with protection are primarily mucosal in nature and induction of mucosal immunity is important for preventing porcine rotavirus infection.

Results

Lactobacillus casei expressing the major protective antigen VP4 of porcine rotavirus (pPG612.1-VP4) or VP4-LTB (heat-labile toxin B sub-unit from Escherichia coli) (pPG612.1-VP4-LTB) fusion protein was used to immunise mice orally. The expression of recombinant pPG612.1-VP4 and pPG612.1-VP4-LTB was confirmed by SDS-PAGE and Western blot analysis and surface-displayed expression on L. casei was verified by immunofluorescence.

Mice orally immunised with recombinant protein-expressing L. casei produced high levels of serum immunoglobulin G (IgG) and mucosal IgA. The IgA titres from mice immunised with pPG612.1-VP4-LTB were higher than titres from pPG612.1-VP4-immunised mice.

The induced antibodies demonstrated neutralising effects on RV infection.

Conclusion

The researchers say that their results demonstrate that VP4 administered in the context of an L. casei expression system is an effective method for stimulating mucosal immunity and that LTB served to further stimulate mucosal immunity suggesting that this strategy can be adapted for use in pigs.

Reference

Qiao X., G. Li, X. Wang, X. Li, M. Liu and Y. Li. 2009. Recombinant porcine rotavirus VP4 and VP4-LTB expressed in Lactobacillus casei induced mucosal and systemic antibody responses in mice. BMC Microbiology, 9:249. doi:10.1186/1471-2180-9-249