scholarly journals Immune Responses to Recombinant Pneumococcal PspA Antigen Delivered by Live Attenuated Salmonella enterica Serovar Typhimurium Vaccine

2002 ◽  
Vol 70 (4) ◽  
pp. 1739-1749 ◽  
Author(s):  
Ho Young Kang ◽  
Jay Srinivasan ◽  
Roy Curtiss
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Salmonella Enterica ◽  
Outer Membrane Proteins ◽  
Oral Immunization ◽  
Recombinant Antigen ◽  
Heterologous Antigen ◽  
Recombinant Antigens ◽  
Serovar Typhimurium ◽  
Type Response

ABSTRACT Attenuated Salmonella enterica serovar Typhimurium expressing recombinant antigens from other pathogens elicits primarily a Th1-type dominant immune response to both recombinant and Salmonella antigens. The immunogenicity and appropriate subcellular location of the recombinant antigen in the Salmonella vaccine strain may contribute to augmenting immune responses by facilitating adequate exposure of recombinant antigen to antigen-presenting cells for processing. To allow for secretion from gram-negative bacteria and overexpression of antigen, a DNA fragment encoding a highly antigenic α-helical region of PspA (pneumococcal surface protein A) was subcloned downstream from the β-lactamase signal sequence in the multicopy Asd+ pYA3493 vector to create pYA3494. pYA3493 was derived from a class of Asd+ vectors with reduced expression of Asd to minimize selective disadvantage and enhance immunization of expressed recombinant antigens. The S. enterica serovar Typhimurium vaccine strain was constructed by the introduction of deletion mutations Δcrp-28 and ΔasdA16. Approximately 50% of the recombinant PspA (rPspA) expressed in a Salmonella strain harboring pYA3494 was detected in the combined supernatant and periplasmic fractions of broth-grown recombinant Salmonella. After a single oral immunization in BALB/c mice with 109 CFU of the recombinant Salmonella vaccine strain carrying pYA3494, immunoglobulin G (IgG) antibody responses were stimulated to both the heterologous antigen rPspA and Salmonella lipopolysaccharide (LPS) and outer membrane proteins (OMPs). About half, and even more at later times after immunization, of the antibodies induced to rPspA were IgG1 (indicating a Th2-type response), whereas 60 to 70% of the antibodies to LPS and 80 to 90% of those to OMPs were IgG2a (indicating a Th1-type response). A sublethal infection with Streptococcus pneumoniae WU2 boosted PspA antibody levels and maintained IgG2a/IgG1 ratios similar to those seen before the challenge. Oral immunization with Salmonella-PspA vaccine protected 60% of immunized mice from death after intraperitoneal challenge with 50 times the 50% lethal dose of virulent S. pneumoniae WU2.

scholarly journals Mucosal and Systemic Immune Responses to Chimeric Fimbriae Expressed by Salmonella enterica Serovar Typhimurium Vaccine Strains

2000 ◽  
Vol 68 (6) ◽  
pp. 3129-3139 ◽  
Author(s):  
Huaiqing Chen ◽  
Dieter M. Schifferli
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Salmonella Enterica ◽  
Genetic Manipulation ◽  
Genetically Engineered ◽  
Spike Protein ◽  
Transmissible Gastroenteritis Virus ◽  
Heterologous Antigen ◽  
Serovar Typhimurium

ABSTRACT Recombinant live oral vaccines expressing pathogen-derived antigens offer a unique set of attractive properties. Among these are the simplicity of administration, the capacity to induce mucosal and systemic immunity, and the advantage of permitting genetic manipulation for optimal antigen presentation. In this study, the benefit of having a heterologous antigen expressed on the surface of a live vector rather than intracellularly was evaluated. Accordingly, the immune response of mice immunized with a Salmonella enterica serovar Typhimurium vaccine strain expressing the Escherichia coli 987P fimbrial antigen on its surface (Fas+) was compared with the expression in the periplasmic compartment (Fas−). Orally immunized BALB/c mice showed that 987P fimbriated Salmonella serovar Typhimurium CS3263 (aroA asd) with pCS151 (fas+asd +) elicited a significantly higher level of 987P-specific systemic immunoglobulin G (IgG) and mucosal IgA than serovar Typhimurium CS3263 with pCS152 (fasD mutant,asd +) expressing 987P periplasmic antigen. Further studies were aimed at determining whether the 987P fimbriae expressed by serovar Typhimurium χ4550 (cya crp asd) could be used as carriers of foreign epitopes. For this, the vaccine strain was genetically engineered to express chimeric fimbriae carrying the transmissible gastroenteritis virus (TGEV) C (379-388) and A (521-531) epitopes of the spike protein inserted into the 987P major fimbrial subunit FasA. BALB/c mice administered orally serovar Typhimurium χ4550 expressing the chimeric fimbriae from thetet promoter in pCS154 (fas+asd +) produced systemic antibodies against both fimbria and the TGEV C epitope but not against the TGEV A epitope. To improve the immunogenicity of the chimeric fimbriae, the in vivo inducible nirB promoter was inserted into pCS154, upstream of the fas genes, to create pCS155. In comparison with the previously used vaccine, BALB/c mice immunized orally with serovar Typhimurium χ4550/pCS155 demonstrated significantly higher levels of serum IgG and mucosal IgA against 987P fimbria. Moreover, mucosal IgA against the TGEV C epitope was only detected with serovar Typhimurium χ4550/pCS155. The induced antibodies also recognized the epitopes in the context of the full-length TGEV spike protein. Hence, immune responses to heterologous chimeric fimbriae onSalmonella vaccine vectors can be optimized by using promoters known to be activated in vivo.

scholarly journals Effect of Preexisting Immunity to Salmonella on the Immune Response to Recombinant Salmonella enterica Serovar Typhimurium Expressing a Porphyromonas gingivalisHemagglutinin

2000 ◽  
Vol 68 (6) ◽  
pp. 3116-3120 ◽  
Author(s):  
James J. Kohler ◽  
Latha B. Pathangey ◽  
Sheila R. Gillespie ◽  
Thomas A. Brown
Keyword(s):  
Immune Responses ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Oral Vaccine ◽  
Oral Immunization ◽  
Primary Response ◽  
Serum Iga ◽  
Serovar Typhimurium ◽  
Live Oral Vaccine ◽  
Carrier Strain

ABSTRACT Recombinant Salmonella strains expressing foreign heterologous genes have been extensively studied as live oral vaccine delivery vectors. We have investigated the mucosal and systemic immune responses following oral immunization with a recombinantSalmonella enterica serovar Typhimurium expressing the hemagglutinin HagB from Porphyromonas gingivalis, a suspected etiological agent of adult periodontal disease. We have previously shown a primary mucosal and systemic response following oral immunization with χ4072/pDMD1 and recall responses following boosting at 14 weeks after primary immunization. In this study, we examined the effects of earlier boosting as well as the effects of deliberately induced immunity to the Salmonella carrier strain on subsequent immune responses. Mice boosted at week 7 following immunization, a point which corresponded to the peak of the primary response, generally showed lower responses than those boosted at week 14. When mice were preimmunized with the Salmonella carrier alone and then immunized with the recombinant strain 7 or 14 weeks later, significant reductions were seen for serum immunoglobulin G (IgG) antibodies at week 14 and for salivary IgA at week 7. No reductions were seen in serum IgA or vaginal wash IgA antibodies. Mice appear to be refractory to boosting with orally administered salmonellae at 7 weeks. Deliberate immunization with the carrier strain did not appreciably affect recall responses at 14 weeks, with the exception of the serum IgG responses, nor did it affect colonization of the Peyer's patches.

scholarly journals Oral Immunization with Attenuated Salmonella enterica Serovar Typhimurium Encoding Cryptosporidium parvum Cp23 and Cp40 Antigens Induces a Specific Immune Response in Mice

2009 ◽  
Vol 16 (9) ◽  
pp. 1272-1278 ◽  
Author(s):  
Alvaro J. Benitez ◽  
Nina McNair ◽  
Jan R. Mead
Keyword(s):  
Vaccine Strain ◽  
Delivery System ◽  
Cryptosporidium Parvum ◽  
Salmonella Enterica ◽  
Plasmid Stability ◽  
Oral Immunization ◽  
Antibody Responses ◽  
Vector System ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serovar Typhimurium

ABSTRACT Attenuated Salmonella enterica serovar Typhimurium vaccine strain SL3261 was used as an antigen delivery system for the oral immunization of mice against two Cryptosporidium parvum antigens, Cp23 and Cp40. Each antigen was subcloned into the pTECH1 vector system, which allows them to be expressed as fusion proteins with highly immunogenic fragment C of tetanus toxin under the control of the anaerobically inducible nirB promoter. The recombinant vector was introduced into Salmonella Typhimurium vaccine strain SL3261, and the stable soluble expression of the chimeric protein was evaluated and confirmed by Western blotting with polyclonal C. parvum antisera. Mice were inoculated orally with a single dose of SL3261/pTECH-Cp23 or Cp40, respectively, and plasmid stability was demonstrated both in vitro and in vivo. Specific serum immunoglobulin G (IgG) antibodies against the Cp23 or Cp40 antigen were detected by enzyme-linked immunosorbent assay 35 days after immunization. Also, serum IgA and mucosal (feces) IgA antibodies were detected in 30% of the mice immunized with Cp23. In addition, prime-boosting with Cp23 and Cp40 DNA vaccine vectors followed by Salmonella immunization significantly increased antibody responses to both antigens. Our data show that a single oral inoculation with recombinant S. Typhimurium SL3261 can induce specific antibody responses to the Cp23 or Cp40 antigen from C. parvum in mice, suggesting that recombinant Salmonella is a feasible delivery system for a vaccine against C. parvum infection.

scholarly journals Induction of Protective Immunity againstStreptococcus mutans Colonization after Mucosal Immunization with Attenuated Salmonella enterica Serovar Typhimurium Expressing an S. mutans Adhesin under the Control of In Vivo-Inducible nirB Promoter

2001 ◽  
Vol 69 (4) ◽  
pp. 2154-2161 ◽  
Author(s):  
Yan Huang ◽  
George Hajishengallis ◽  
Suzanne M. Michalek
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Salmonella Enterica ◽  
Virulent Strain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Booster Immunization ◽  
Serovar Typhimurium ◽  
Tooth Surfaces

ABSTRACT The purpose of the present study was to evaluate the effectiveness of an attenuated Salmonella enterica serovar Typhimurium vaccine strain expressing the saliva-binding region (SBR) of theStreptococcus mutans antigen I/II adhesin, either alone or linked with the mucosal adjuvant cholera toxin A2 and B subunits (CTA2/B) and under the control of the anaerobically induciblenirB promoter, in inducing a protective immune response against S. mutans infection. BALB/c mice were immunized by either the intranasal or the intragastric route with a single dose of 109 or 1010 Salmonella CFU, respectively. The Salmonella vaccine strain expressing an unrelated antigen (fragment C of tetanus toxin [TetC]) was also used for immunization as a control. Samples of serum and secretion (saliva and vaginal washes) were collected prior to and following immunization and assessed for antibody activity by enzyme-linked immunosorbent assay. Anti-SBR antibodies were detected in the serum and saliva of experimental animals by week 3 after immunization. A booster immunization at week 17 after the initial immunization resulted in enhanced immune responses to the SBR. The serum immunoglobulin G subclass profiles were indicative of T helper type 1 responses against both the vector and the SBR antigen. To determine the effectiveness of these responses on the protection against S. mutansinfection, mice were challenged after the second immunization with a virulent strain of S. mutans which was resistant to tetracycline and erythromycin. Prior to the challenge, mice were treated for 5 days with tetracycline, erythromycin, and penicillin.S. mutans was initially recovered from all of the challenged mice. This bacterium persisted at high levels for at least 5 weeks in control TetC-immunized or nonimmunized mice despite the reappearance of indigenous oral organisms. However, mice immunized withSalmonella clones expressing SBR or SBR-CTA2/B demonstrated a significant reduction in the number of S. mutans present in plaque compared to the control groups. These results provide evidence for the effectiveness of the Salmonella vector in delivering the SBR antigen for the induction of mucosal and systemic immune responses to SBR. Furthermore, the induction of a salivary anti-SBR response corresponded with protection against S. mutans colonization of tooth surfaces.

scholarly journals Regulated Delayed Expression of rfaH in an Attenuated Salmonellaenterica Serovar Typhimurium Vaccine Enhances Immunogenicity of Outer Membrane Proteins and a Heterologous Antigen

2009 ◽  
Vol 77 (12) ◽  
pp. 5572-5582 ◽  
Author(s):  
Qingke Kong ◽  
Qing Liu ◽  
Kenneth L. Roland ◽  
Roy Curtiss
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Lethal Dose ◽  
Enteric Bacteria ◽  
Lymphoid Tissues ◽  
Heterologous Antigen ◽  
O Antigen ◽  
Mutant Strains ◽  
Serovar Typhimurium

ABSTRACT RfaH is a transcriptional antiterminator that reduces the polarity of long operons encoding secreted and surface-associated cell components of Salmonella enterica serovar Typhimurium, including O antigen and lipopolysaccharide core sugars. A ΔrfaH mutant strain is attenuated in mice (50% lethal dose [LD50], >108 CFU). To examine the potential for using rfaH in conjunction with other attenuating mutations, we designed a series of strains in which we replaced the native rfaH promoter with the tightly regulated arabinose-dependent araC PBAD promoter so that rfaH expression was dependent on exogenously supplied arabinose provided during in vitro growth. Following colonization of host lymphoid tissues, where arabinose was not available, the PBAD promoter was no longer active and rfaH was not expressed. In the absence of RfaH, O antigen and core sugars were not synthesized. We constructed three mutant strains that expressed different levels of RfaH by altering the ribosome-binding sequence and start codon. One mutation, ΔPrfaH178, was introduced into the attenuated vaccine strain χ9241 (ΔpabA ΔpabB ΔasdA) expressing the pneumococcal surface protein PspA from an Asd+ balanced-lethal plasmid. Mice immunized with this strain and boosted 4 weeks later induced higher levels of serum immunoglobulin G specific for PspA and for outer membrane proteins from other enteric bacteria than either an isogenic ΔrfaH derivative or the isogenic RfaH+ parent. Eight weeks after primary oral immunization, mice were challenged with 200 LD50 of virulent S treptococcus pneumoniae WU2. Immunization with ΔPrfaH178 mutant strains led to increased levels of protection compared to that of the parent χ9241 and of a ΔrfaH derivative of χ9241.

scholarly journals T- and B-Cell Immune Responses of Patients Who Had Undergone Colectomies to Oral Administration of Salmonella enterica Serovar Typhi Ty21a Vaccine

2003 ◽  
Vol 10 (3) ◽  
pp. 426-430 ◽  
Author(s):  
Jan Kilhamn ◽  
Samuel B. Lundin ◽  
Hans Brevinge ◽  
Ann-Mari Svennerholm ◽  
Marianne Jertborn
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
B Cell ◽  
Healthy Volunteers ◽  
Vaccine Strain ◽  
Salmonella Enterica ◽  
Antibody Responses ◽  
Igg Antibody ◽  
Iga Antibody ◽  
Ifn Γ

ABSTRACT The capacity of an oral live attenuated Salmonella enterica serovar Typhi Ty21a vaccine to induce immune responses in patients who had undergone colectomies because of ulcerative colitis was evaluated, and these responses were compared with those of healthy volunteers. Purified CD4+ and CD8+ T cells from peripheral blood were stimulated in vitro by using the heat-killed Ty21a vaccine strain, and the proliferation and gamma interferon (IFN-γ) production were measured before and 7 or 8 days after vaccination. Salmonella-specific immunoglobulin A (IgA) and IgG antibody responses in serum along with IgA antibody responses in ileostomy fluids from the patients who had undergone colectomies were also evaluated. Three doses of vaccine given 2 days apart failed to induce proliferative T-cell responses in all the six patients who had undergone colectomies, and increases in IFN-γ production were found only among the CD8+ cells from three of the patients. In contrast, both proliferative responses and increased IFN-γ production were observed among CD4+ and CD8+ T cells from 3 and 6 of 10 healthy volunteers, respectively. Salmonella-specific IgA and/or IgG antibody responses in serum were observed for five (56%) of nine patients who had undergone colectomies and in 15 (88%) of 17 healthy volunteers. In ileostomy fluids, significant anti-Salmonella IgA antibody titer increases were detected in six (67%) of nine patients who had undergone colectomies. The impaired T- and B-cell immune responses found after vaccination in the circulation of patients who have undergone colectomies may be explained by a diminished colonization of the Ty21a vaccine strain due to the lack of a terminal ileum and colon.

scholarly journals Flagellin from Recombinant Attenuated Salmonella enterica Serovar Typhimurium Reveals a Fundamental Role in Chicken Innate Immunity

2012 ◽  
Vol 19 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Zhiming Pan ◽  
Qiuxia Cong ◽  
Shizhong Geng ◽  
Qiang Fang ◽  
Xilong Kang ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Immune Responses ◽  
Salmonella Enterica ◽  
Rational Design ◽  
Bacterial Load ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Content Type ◽  
Serovar Typhimurium

ABSTRACTRecombinant attenuatedSalmonellavaccines have been extensively studied, with a focus on eliciting specific immune responses against foreign antigens. However, very little is known about the innate immune responses, particularly the role of flagellin, in the induction of innate immunity triggered by recombinant attenuatedSalmonellain chickens. In the present report, we describe twoSalmonella entericaserovar Typhimurium vaccine strains, wild-type (WT) or flagellin-deficient (flhD)Salmonella, both expressing the fusion protein (F) gene of Newcastle disease virus. We examined the bacterial load and spatiotemporal kinetics of expression of inflammatory cytokine, chemokine, and Toll-like receptor 5 (TLR5) genes in the cecum, spleen, liver, and heterophils following oral immunization of chickens with the twoSalmonellastrains. TheflhDmutant exhibited an enhanced ability to establish systemic infection compared to the WT. In contrast, the WT strain induced higher levels of interleukin-1β (IL-1β), CXCLi2, and TLR5 mRNAs in cecum, the spleen, and the heterophils than theflhDmutant at different times postinfection. Collectively, the present data reveal a fundamental role of flagellin in the innate immune responses induced by recombinant attenuatedSalmonellavaccines in chickens that should be considered for the rational design of novel vaccines for poultry.

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