Tightly regulated bacteriolysis for production of empty Salmonella Enteritidis envelope.
To avoid leaky expression of the bacterial host-toxic PhiX174 lysis gene E from the λpR promoter, a convergent promoter construct was made in which gene E was placed between a sense λpR promoter and an anti-sense P araBAD promoter. In the presence of l-arabinose, leaky transcription of lysis gene E at 28°C from the sense λpR promoter was repressed by an anti-sense RNA simultaneously expressed from the P araBAD promoter. The stringent repression of lysis gene E in the absence of induction temperature resulted into higher concentration of bacteria in culture suspension, and consequently higher and stable production of a Salmonella Enteritidis (S. Enteritidis) ghost. The immunogenicity of the S. Enteritidis ghost was evaluated by immunizing chickens. Chickens from the immunized group demonstrated a significant increase in the levels of S. Enteritidis-specific plasma IgG, intestinal sIgA, and lymphocyte proliferative response. After virulent S. Enteritidis challenge, the immunized group exhibited decreased bacterial recovery from organs compared with the non-immunized group. Together, these results demonstrate that the stringent molecular control over leaky transcription of lysis gene E enabled the stable production of S. Enteritidis ghost, and immunization with the S. Enteritidis ghost can protect chickens by inducing robust humoral and cellular immune responses.
College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea.
Chetan V
CV
Jawale
Swine Science and Technology Center, Gyeongnam National University of Science and Technology, 150 Chilam-dong, Jinju, Gyeongnam, 660-758, Republic of Korea.
Sam Woong
SW
Kim
College of Veterinary Medicine, Chonbuk National University, Jeonju 561-756, Republic of Korea. Electronic address: johnhlee@jbnu.ac.kr.
John Hwa
JH
Lee
D000818:Animals; D001433:Bacteriolysis; D002645:Chickens; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D007111:Immunity, Cellular / Q000276:immunology; D056724:Immunity, Humoral / Q000276:immunology; D007114:Immunization; D007071:Immunoglobulin A, Secretory / Q000276:immunology; D008855:Microscopy, Electron, Scanning; D010957:Plasmids / Q000235:genetics; D011201:Poultry Diseases / Q000517:prevention & control; D012481:Salmonella Infections, Animal / Q000517:prevention & control; D012477:Salmonella enteritidis / Q000276:immunology* / Q000648:ultrastructure; D015164:Vaccines, Inactivated / Q000276:immunology*
D007071:Immunoglobulin A, Secretory; D015164:Vaccines, Inactivated
Bacterial ghost; Convergent promoter; Leaky transcription; Lysis gene E; Salmonella Enteritidis; Tight regulation