Oral immunization of mice with engineered Lactobacillus gasseri NM713 strain expressing Streptococcus pyogenes M6 antigen.
The aim of this in vivo study was to evaluate the effects of a recombinant probiotic strain, Lactobacillus gasseri NM713, which expresses the conserved region of streptococcal M6 protein (CRR6), as an oral vaccine against Streptococcus pyogenes. A dose of 10(9) cells of the recombinant strain in 150 μL PBS buffer was administered orally to a group of mice. One control group received an equivalent dose of Lb. gasseri NM613 (containing the empty plasmid without insert) or and another control group received PBS buffer. Each group contained 30 mice. The immunization protocol was followed on three consecutive days, after which two booster doses were administered at two week intervals. Fecal and serum samples were collected from the mice on Days 18, 32, 46, 58 after the first immunization and Day 0 prior to immunization. Anti-CRR6 IgA and IgG concentrations were measured by ELISA in fecal and sera samples, respectively, to assess immune responses. Vaccination with the recombinant Lb. gasseri NM713 strain induced significant protection after nasal challenge with S. pyogenes, only a small percentage of this group developing streptococcal infection (10%) or dying of it (3.3%) compared with the NM613 and PBS control groups, high percentages of which developed streptococcal infection (43.3% and 46.7%, respectively) and died of it (46.7% and 53%, respectively). These results indicate that recombinant Lb. gasseri NM713 has potential as an oral delivery vaccine against streptococcus group A.
['Mansour|Nahla M|NM|', 'Abdelaziz|Sahar A|SA|']
D000281:Administration, Intranasal D000284:Administration, Oral D000818:Animals D000907:Antibodies, Bacterial D000942:Antigens, Bacterial D001425:Bacterial Outer Membrane Proteins D002352:Carrier Proteins D004195:Disease Models, Animal D015870:Gene Expression D007114:Immunization D007070:Immunoglobulin A D007074:Immunoglobulin G D000069998:Lactobacillus gasseri D051379:Mice D019936:Probiotics D013290:Streptococcal Infections D022541:Streptococcal Vaccines D013297:Streptococcus pyogenes
probiotics oral vaccine Lb. gasseri S. pyogenes