TY - JOUR
T1 - The Asd+-DadB+ dual-plasmid system offers a novel means to deliver multiple protective antigens by a recombinant attenuated Salmonella vaccine
AU - Xin, Wei
AU - Wanda, Soo Young
AU - Zhang, Xiangmin
AU - Santander, Javier
AU - Scarpellini, Giorgio
AU - Ellis, Karen
AU - Alamuri, Praveen
AU - Curtiss, Roy
PY - 2012/10
Y1 - 2012/10
N2 - We developed means to deliver multiple heterologous antigens on dual plasmids with non-antibiotic-resistance markers in a single recombinant attenuated vaccine strain of Salmonella enterica serotype Typhimurium. The first component of this delivery system is a strain of S. Typhimurium carrying genomic deletions in alr, dadB, and asd, resulting in obligate requirements for diaminopimelic acid (DAP) and D-alanine for growth. The second component is the Asd+-DadB+ plasmid pair carrying wildtype copies of asdA and dadB, respectively, to complement the mutations. To evaluate the protection efficacy of the dual-plasmid vaccine, S. Typhimurium strain Χ9760 (a strain with multiple attenuating mutations: Δasd Δalr ΔdadB ΔrecF) was transformed with Asd+ and DadB+ plasmids specifying pneumococcal antigens PspA and PspC, respectively. Both plasmids were stable in Χ9760 for 50 generations when grown in nonselective medium. This was significantly (P<0.05) greater than the stability seen in its recF+ counterpart Χ9590 and could be attributed to reduced interplasmid recombination in Χ9760. Oral immunization of BALB/c mice with 1 × 109 CFU of Χ9760 (carrying Asd+-PspA and DadB+-PspC plasmids) elicited a dominant Th1-type serum IgG response against both antigens and protected mice against intraperitoneal challenge with 200 50% lethal doses (LD50s) of virulent Streptococcus pneumoniae strain WU2 or intravenous challenge with 100 LD50s of virulent S. pneumoniae strain L81905 or intranasal challenge with a lethal dose of S. pneumoniae A66.1 in a pneumonia model. Protection offered by Χ9760 was superior to that offered by the mixture of two strains, Χ9828 (Asd+-PspA) and Χ11026 (DadB+-PspC). This novel dual-plasmid system marks a remarkable improvement in the development of live bacterial vaccines.
AB - We developed means to deliver multiple heterologous antigens on dual plasmids with non-antibiotic-resistance markers in a single recombinant attenuated vaccine strain of Salmonella enterica serotype Typhimurium. The first component of this delivery system is a strain of S. Typhimurium carrying genomic deletions in alr, dadB, and asd, resulting in obligate requirements for diaminopimelic acid (DAP) and D-alanine for growth. The second component is the Asd+-DadB+ plasmid pair carrying wildtype copies of asdA and dadB, respectively, to complement the mutations. To evaluate the protection efficacy of the dual-plasmid vaccine, S. Typhimurium strain Χ9760 (a strain with multiple attenuating mutations: Δasd Δalr ΔdadB ΔrecF) was transformed with Asd+ and DadB+ plasmids specifying pneumococcal antigens PspA and PspC, respectively. Both plasmids were stable in Χ9760 for 50 generations when grown in nonselective medium. This was significantly (P<0.05) greater than the stability seen in its recF+ counterpart Χ9590 and could be attributed to reduced interplasmid recombination in Χ9760. Oral immunization of BALB/c mice with 1 × 109 CFU of Χ9760 (carrying Asd+-PspA and DadB+-PspC plasmids) elicited a dominant Th1-type serum IgG response against both antigens and protected mice against intraperitoneal challenge with 200 50% lethal doses (LD50s) of virulent Streptococcus pneumoniae strain WU2 or intravenous challenge with 100 LD50s of virulent S. pneumoniae strain L81905 or intranasal challenge with a lethal dose of S. pneumoniae A66.1 in a pneumonia model. Protection offered by Χ9760 was superior to that offered by the mixture of two strains, Χ9828 (Asd+-PspA) and Χ11026 (DadB+-PspC). This novel dual-plasmid system marks a remarkable improvement in the development of live bacterial vaccines.
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U2 - 10.1128/IAI.00620-12
DO - 10.1128/IAI.00620-12
M3 - Article
C2 - 22868499
AN - SCOPUS:84867610365
SN - 0019-9567
VL - 80
SP - 3621
EP - 3633
JO - Infection and immunity
JF - Infection and immunity
IS - 10
ER -