Limits...
Oral Delivery of a Novel Recombinant Streptococcus mitis Vector Elicits Robust Vaccine Antigen-Specific Oral Mucosal and Systemic Antibody Responses and T Cell Tolerance.

Xie E, Kotha A, Biaco T, Sedani N, Zou J, Stashenko P, Duncan MJ, Campos-Neto A, Cayabyab MJ - PLoS ONE (2015)

Bottom Line: Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses.Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance.Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV.

View Article: PubMed Central - PubMed

Affiliation: Global Infectious Disease Research Center and the Department of Immunology and Infectious Diseases, The Forsyth Institute, 245 First Street, Cambridge, Massachusetts, United States of America.

ABSTRACT
The pioneer human oral commensal bacterium Streptococcus mitis has unique biologic features that make it an attractive mucosal vaccine or therapeutic delivery vector. S. mitis is safe as a natural persistent colonizer of the mouth, throat and nasopharynx and the oral commensal bacterium is capable of inducing mucosal antibody responses. A recombinant S. mitis (rS. mitis) that stably expresses HIV envelope protein was generated and tested in the germ-free mouse model to evaluate the potential usefulness of this vector as a mucosal vaccine against HIV. Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses. Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance. Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV. Moreover, the first demonstration of rS. mitis having the ability to elicit T cell tolerance suggest the potential use of rS. mitis as an immunotherapeutic vector to treat inflammatory, allergic and autoimmune diseases.

Show MeSH

Related in: MedlinePlus

rS. mitis expressing HIV Env is stable.To determine the stability of the integrated Env gp120 gene in rS. mitis, four clones (HIVEnvA, B, C, and D) were picked at random and grown anaerobically for 24 hours which represents approximately three generations (7.1 hours per generation) in THB media without erythromycin. Cultures were grown for approximately 30 generations without erythromycin. From each generation 100 and 150 colonies were picked at random and streaked to THB plates with and without erythromycin. For each S. mitis HIV Env clone, the number of Ermr colonies/total number of colonies streaked after 6, 12, 18, 24, and 30 generations was determined (Fig 3A). Expression of Env in the same daughter clones was analyzed by Western blot analysis. Env production in a representative daughter clone (after 30 generations) and the original HIVgp120A clone is shown (Fig 3B).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664415&req=5

pone.0143422.g003: rS. mitis expressing HIV Env is stable.To determine the stability of the integrated Env gp120 gene in rS. mitis, four clones (HIVEnvA, B, C, and D) were picked at random and grown anaerobically for 24 hours which represents approximately three generations (7.1 hours per generation) in THB media without erythromycin. Cultures were grown for approximately 30 generations without erythromycin. From each generation 100 and 150 colonies were picked at random and streaked to THB plates with and without erythromycin. For each S. mitis HIV Env clone, the number of Ermr colonies/total number of colonies streaked after 6, 12, 18, 24, and 30 generations was determined (Fig 3A). Expression of Env in the same daughter clones was analyzed by Western blot analysis. Env production in a representative daughter clone (after 30 generations) and the original HIVgp120A clone is shown (Fig 3B).

Mentions: To determine the stability of the integrated HIV-1 Env gp120 gene in rS. mitis, four clones were picked at random and grown anaerobically for 30 generations. Loss of erythromycin-resistance was taken as an indication of the loss of the Env transgene. The progeny from all four clones were stable, with no loss of erythromycin resistance after ten subcultures or 30 generations of replication without antibiotic (Fig 3A). In addition, we analyzed the expression of Env in the same daughter clones. Western blot analysis revealed that they secreted the same amount of Env antigen as the original rS. mitis clones; Env production in a representative daughter clone after 30 generations and the original HIVgp120A clone is shown (Fig 3B). These results indicate that our rS. mitis is stable, a vaccine property that makes it a good candidate for further preclinical testing.


Oral Delivery of a Novel Recombinant Streptococcus mitis Vector Elicits Robust Vaccine Antigen-Specific Oral Mucosal and Systemic Antibody Responses and T Cell Tolerance.

Xie E, Kotha A, Biaco T, Sedani N, Zou J, Stashenko P, Duncan MJ, Campos-Neto A, Cayabyab MJ - PLoS ONE (2015)

rS. mitis expressing HIV Env is stable.To determine the stability of the integrated Env gp120 gene in rS. mitis, four clones (HIVEnvA, B, C, and D) were picked at random and grown anaerobically for 24 hours which represents approximately three generations (7.1 hours per generation) in THB media without erythromycin. Cultures were grown for approximately 30 generations without erythromycin. From each generation 100 and 150 colonies were picked at random and streaked to THB plates with and without erythromycin. For each S. mitis HIV Env clone, the number of Ermr colonies/total number of colonies streaked after 6, 12, 18, 24, and 30 generations was determined (Fig 3A). Expression of Env in the same daughter clones was analyzed by Western blot analysis. Env production in a representative daughter clone (after 30 generations) and the original HIVgp120A clone is shown (Fig 3B).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664415&req=5

pone.0143422.g003: rS. mitis expressing HIV Env is stable.To determine the stability of the integrated Env gp120 gene in rS. mitis, four clones (HIVEnvA, B, C, and D) were picked at random and grown anaerobically for 24 hours which represents approximately three generations (7.1 hours per generation) in THB media without erythromycin. Cultures were grown for approximately 30 generations without erythromycin. From each generation 100 and 150 colonies were picked at random and streaked to THB plates with and without erythromycin. For each S. mitis HIV Env clone, the number of Ermr colonies/total number of colonies streaked after 6, 12, 18, 24, and 30 generations was determined (Fig 3A). Expression of Env in the same daughter clones was analyzed by Western blot analysis. Env production in a representative daughter clone (after 30 generations) and the original HIVgp120A clone is shown (Fig 3B).
Mentions: To determine the stability of the integrated HIV-1 Env gp120 gene in rS. mitis, four clones were picked at random and grown anaerobically for 30 generations. Loss of erythromycin-resistance was taken as an indication of the loss of the Env transgene. The progeny from all four clones were stable, with no loss of erythromycin resistance after ten subcultures or 30 generations of replication without antibiotic (Fig 3A). In addition, we analyzed the expression of Env in the same daughter clones. Western blot analysis revealed that they secreted the same amount of Env antigen as the original rS. mitis clones; Env production in a representative daughter clone after 30 generations and the original HIVgp120A clone is shown (Fig 3B). These results indicate that our rS. mitis is stable, a vaccine property that makes it a good candidate for further preclinical testing.

Bottom Line: Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses.Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance.Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV.

View Article: PubMed Central - PubMed

Affiliation: Global Infectious Disease Research Center and the Department of Immunology and Infectious Diseases, The Forsyth Institute, 245 First Street, Cambridge, Massachusetts, United States of America.

ABSTRACT
The pioneer human oral commensal bacterium Streptococcus mitis has unique biologic features that make it an attractive mucosal vaccine or therapeutic delivery vector. S. mitis is safe as a natural persistent colonizer of the mouth, throat and nasopharynx and the oral commensal bacterium is capable of inducing mucosal antibody responses. A recombinant S. mitis (rS. mitis) that stably expresses HIV envelope protein was generated and tested in the germ-free mouse model to evaluate the potential usefulness of this vector as a mucosal vaccine against HIV. Oral vaccination led to the efficient and persistent bacterial colonization of the mouth and the induction of both salivary and systemic antibody responses. Interestingly, persistently colonized animals developed antigen-specific systemic T cell tolerance. Based on these findings we propose the use of rS. mitis vaccine vector for the induction of mucosal antibodies that will prevent the penetration of the mucosa by pathogens such as HIV. Moreover, the first demonstration of rS. mitis having the ability to elicit T cell tolerance suggest the potential use of rS. mitis as an immunotherapeutic vector to treat inflammatory, allergic and autoimmune diseases.

Show MeSH
Related in: MedlinePlus