Attenuated Salmonella choleraesuis-mediated RNAi targeted to conserved regions against foot-and-mouth disease virus in guinea pigs and swine.
In this study, specific sequences within three genes (3D, VP4 and 2B) of the foot-and-mouth disease virus (FMDV) genome were determined to be effective RNAi targets. These sequences are highly conserved among different serotype viruses based on sequence analysis. Small interfering RNA (siRNA)-expressing plasmids (p3D-NT19, p3D-NT56, pVP4-NT19, pVP4-NT65 and p2B-NT25) were constructed to express siRNA targeting 3D, VP4 and 2B, respectively. The antiviral potential of these siRNA for various FMDV isolates was investigated in baby hamster kidney (BHK-21) cells and suckling mice. The results show that these siRNA inhibited virus yield 10- to 300-fold for different FMDV isolates of serotype O and serotype Asia I at 48 h post infection in BHK-21 cells compared to control cells. In suckling mice, p3D-NT56 and p2B-NT25 delayed the death of mice. Twenty percent to 40% of the animals that received a single siRNA dose survived 5 days post infection with serotype O or serotype Asia I. We used an attenuated Salmonella choleraesuis (C500) vaccine strain, to carry the plasmid that expresses siRNA directed against the polymerase gene 3D (p3D-NT56) of FMDV. We used guinea pigs to evaluate the inhibitory effects of recombinant S. cho (p3D-NT56/S. cho) on FMDV infection. The results show that 80% of guinea pigs inoculated with 10(9) CFU of p3D-NT56/S. cho and challenged 36 h later with 50 ID(50) of homologous FMDV were protected. We also measured the antiviral activity of p3D-NT56/S. cho in swine. The results indicate that 100% of the animals treated with 5 x 10(9) CFU of p3D-NT56/S. cho were protected in 9 days.
Cong
Wei
W
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, 220 Handan Rd., Shanghai 200433, People's Republic of China.
Jin
Hong
H
Jiang
Chengda
C
Yan
Weiyao
W
Liu
Mingqiu
M
Chen
Jiulian
J
Zuo
Xiaoping
X
Zheng
Zhaoxin
Z
D000818:Animals; D000833:Animals, Suckling; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D017124:Conserved Sequence; D006224:Cricetinae; D005536:Foot-and-Mouth Disease / Q000517:prevention & control* / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000276:immunology; D015967:Gene Expression Regulation, Viral; D006168:Guinea Pigs; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D034622:RNA Interference; D034741:RNA, Small Interfering; D012475:Salmonella / Q000145:classification / Q000235:genetics / Q000276:immunology*; D013552:Swine; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D054334:Viral Regulatory and Accessory Proteins / Q000235:genetics / Q000378:metabolism; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology; D014779:Virus Replication
D001428:Bacterial Vaccines; D034741:RNA, Small Interfering; D014613:Vaccines, Attenuated; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; D014765:Viral Vaccines