scholarly journals A Bivalent Typhoid Live Vector Vaccine Expressing both Chromosome- and Plasmid-Encoded Yersinia pestis Antigens Fully Protects against Murine Lethal Pulmonary Plague Infection

2014 ◽  
Vol 83 (1) ◽  
pp. 161-172 ◽  
Author(s):  
James E. Galen ◽  
Jin Yuan Wang ◽  
Jose A. Carrasco ◽  
Scott A. Lloyd ◽  
Gabriela Mellado-Sanchez ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Protective Efficacy ◽  
Serum Antibody ◽  
Antigen Expression ◽  
Effector Proteins ◽  
Great Promise ◽  
Content Type ◽  
Bivalent Vaccine ◽  
Vector Vaccine ◽  
Boost Immunization

Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. Here we used a live attenuatedSalmonella entericaserovar Typhi strain to create a bivalent mucosal plague vaccine that produces both the protective F1 capsular antigen ofYersinia pestisand the LcrV protein required for secretion of virulence effector proteins. To reduce the metabolic burden associated with the coexpression of F1 and LcrV within the live vector, we balanced expression of both antigens by combining plasmid-based expression of F1 with chromosomal expression of LcrV from three independent loci. The immunogenicity and protective efficacy of this novel vaccine were assessed in mice by using a heterologous prime-boost immunization strategy and compared to those of a conventional strain in which F1 and LcrV were expressed from a single low-copy-number plasmid. The serum antibody responses to lipopolysaccharide (LPS) induced by the optimized bivalent vaccine were indistinguishable from those elicited by the parent strain, suggesting an adequate immunogenic capacity maintained through preservation of bacterial fitness; in contrast, LPS titers were 10-fold lower in mice immunized with the conventional vaccine strain. Importantly, mice receiving the optimized bivalent vaccine were fully protected against lethal pulmonary challenge. These results demonstrate the feasibility of distributing foreign antigen expression across both chromosomal and plasmid locations within a single vaccine organism for induction of protective immunity.

scholarly journals Transcutaneous Immunization with a Band-Aid Prevents Experimental Otitis Media in a Polymicrobial Model

2017 ◽  
Vol 24 (6) ◽  
Author(s):  
Laura A. Novotny ◽  
John D. Clements ◽  
Steven D. Goodman ◽  
Lauren O. Bakaletz
Keyword(s):  
Otitis Media ◽  
Delivery System ◽  
Pediatric Population ◽  
Serum Antibody ◽  
Integration Host Factor ◽  
Great Promise ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Transcutaneous Immunization ◽  
Adhesive Proteins

ABSTRACT Otitis media (OM) is a common pediatric disease, and nontypeable Haemophilus influenzae (NTHI) is the predominant pathogen in chronic OM, recurrent OM, and OM associated with treatment failure. OM is also a polymicrobial disease, wherein an upper respiratory tract viral infection predisposes to ascension of NTHI from the nasopharynx, the site of colonization, to the normally sterile middle ear, resulting in disease. Using a clinically relevant viral-bacterial coinfection model of NTHI-induced OM, we performed transcutaneous immunization (TCI) via a band-aid delivery system to administer each of three promising NTHI vaccine candidates derived from bacterial adhesive proteins and biofilm mediators: recombinant soluble PilA (rsPilA), chimV4, and integration host factor. Each immunogen was admixed with the adjuvant LT(R192G/L211A), a double mutant of Escherichia coli heat-labile enterotoxin, and assessed for relative ability to prevent the onset of experimental OM. For each cohort, the presence of circulating immunogen-specific antibody-secreting cells and serum antibody was confirmed prior to intranasal NTHI challenge. After bacterial challenge, blinded video otoscopy and tympanometry revealed a significant reduction in the proportion of animals with signs of OM compared to levels in animals receiving adjuvant only, with an overall vaccine efficacy of 64 to 77%. These data are the first to demonstrate the efficacy afforded by TCI with a band-aid vaccine delivery system in a clinically relevant polymicrobial model of OM. The simplicity of TCI with a band-aid and the significant efficacy observed here hold great promise for reducing the global burden of OM in the pediatric population.

scholarly journals Comparative Protective Efficacies of Novel Avian Paramyxovirus-Vectored Vaccines against Virulent Infectious Bronchitis Virus in Chickens

Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 697
Author(s):  
Edris Shirvani ◽  
Siba K. Samal
Keyword(s):  
Infectious Bronchitis Virus ◽  
Vaccine Candidate ◽  
Protective Efficacy ◽  
Study Groups ◽  
Avian Paramyxovirus ◽  
S Protein ◽  
Vector Vaccine ◽  
Infectious Bronchitis ◽  
Boost Immunization ◽  
Highly Virulent

Viral vectored vaccines are desirable alternatives for conventional infectious bronchitis virus (IBV) vaccines. We have recently shown that a recombinant Newcastle disease virus (rNDV) strain LaSota expressing the spike (S) protein of IBV strain Mass-41 (rLaSota/IBV-S) was a promising vaccine candidate for IBV. Here we evaluated a novel chimeric rNDV/avian paramyxovirus serotype 2 (rNDV/APMV-2) as a vaccine vector against IBV. The rNDV/APMV-2 vector was chosen because it is much safer than the rNDV strain LaSota vector, particularly for young chicks and chicken embryos. In order to determine the effectiveness of this vector, a recombinant rNDV/APMV-2 expressing the S protein of IBV strain Mass-41 (rNDV/APMV-2/IBV-S) was constructed. The protective efficacy of this vector vaccine was compared to that of the rNDV vector vaccine. In one study, groups of one-day-old specific-pathogenic-free (SPF) chickens were immunized with rLaSota/IBV-S and rNDV/APMV-2/IBV-S and challenged four weeks later with the homologous highly virulent IBV strain Mass-41. In another study, groups of broiler chickens were single (at day one or three weeks of age) or prime-boost (prime at day one and boost at three weeks of age) immunized with rLaSota/IBV-S and/or rNDV-APMV-2/IBV-S. At weeks six of age, chickens were challenged with a highly virulent IBV strain Mass-41. Our challenge study showed that novel rNDV/APMV-2/IBV-S provided similar protection as rLaSota/IBV-S in SPF chickens. However, compared to prime-boost immunization of chickens with chimeric rNDV/APMV-2, rLaSota/IBV-S and/or a live IBV vaccine, single immunization of chickens with rLaSota/IBV-S, or live IBV vaccine provided better protection against IBV. In conclusion, we have developed the novel rNDV/APMV-2 vector expressing S protein of IBV that can be a safer vaccine against IB in chickens. Our results also suggest a single immunization with a LaSota vectored IBV vaccine candidate provides better protection than prime-boost immunization regimens.

scholarly journals IQGAP1 Is Important for Activation of Caspase-1 in Macrophages and Is Targeted by Yersinia pestis Type III Effector YopM

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Lawton K. Chung ◽  
Naomi H. Philip ◽  
Valentina A. Schmidt ◽  
Antonius Koller ◽  
Till Strowig ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Immune Defense ◽  
Effector Proteins ◽  
Innate Immune ◽  
Scaffolding Protein ◽  
Host Proteins ◽  
Content Type ◽  
Binding Partner ◽  
Caspase 1 ◽  
Binding Partners

ABSTRACTYopM is a leucine-rich repeat (LRR)-containing effector in severalYersiniaspecies, includingYersinia pestisandY. pseudotuberculosis. DifferentYersiniastrains encode distinct YopM isoforms with variable numbers of LRRs but conserved C-terminal tails. A 15-LRR isoform inY. pseudotuberculosisYPIII was recently shown to bind and inhibit caspase-1 via a YLTD motif in LRR 10, and attenuation of YopM−YPIII was reversed in mice lacking caspase-1, indicating that caspase-1 inhibition is a major virulence function of YopMYPIII. To determine if other YopM proteins inhibit caspase-1, we utilizedY. pseudotuberculosisstrains natively expressing a 21-LRR isoform lacking the YLTD motif (YopM32777) or ectopically expressing aY. pestis15-LRR version with a functional (YopMKIM) or inactivated (YopMKIMD271A) YLTD motif. Results of mouse and macrophage infections with these strains showed that YopM32777, YopMKIM, and YopMKIMD271A inhibit caspase-1 activation, indicating that the YLTD motif is dispensable for this activity. Analysis of YopMKIMdeletion variants revealed that LRRs 6 to 15 and the C-terminal tail are required to inhibit caspase-1 activation. YopM32777, YopMKIM, and YopMKIMdeletion variants were purified, and binding partners in macrophage lysates were identified. Caspase-1 bound to YopMKIMbut not YopM32777. Additionally, YopMKIMbound IQGAP1 and the use ofIqgap1−/−macrophages revealed that this scaffolding protein is important for caspase-1 activation upon infection with YopM−Y. pseudotuberculosis. Thus, while multiple YopM isoforms inhibit caspase-1 activation, their variable LRR domains bind different host proteins to perform this function and the LRRs of YopMKIMtarget IQGAP1, a novel regulator of caspase-1, in macrophages.IMPORTANCEActivation of caspase-1, mediated by macromolecular complexes termed inflammasomes, is important for innate immune defense against pathogens. Pathogens can, in turn, subvert caspase-1-dependent responses through the action of effector proteins. For example, theYersiniaeffector YopM inhibits caspase-1 activation by arresting inflammasome formation. This caspase-1 inhibitory activity has been studied in a specific YopM isoform, and in this case, the protein was shown to act as a pseudosubstrate to bind and inhibit caspase-1. DifferentYersiniastrains encode distinct YopM isoforms, many of which lack the pseudosubstrate motif. We studied additional isoforms and found that these YopM proteins inhibit caspase-1 activation independently of a pseudosubstrate motif. We also identified IQGAP1 as a novel binding partner of theYersinia pestisYopMKIMisoform and demonstrated that IQGAP1 is important for caspase-1 activation in macrophages infected withYersinia. Thus, this study reveals new insights into inflammasome regulation duringYersiniainfection.

scholarly journals Acquisition of Maternal Antibodies both from the Placenta and by Lactation Protects Mouse Offspring from Yersinia pestis Challenge

2012 ◽  
Vol 19 (11) ◽  
pp. 1746-1750 ◽  
Author(s):  
Zhizhen Qi ◽  
Haihong Zhao ◽  
Qingwen Zhang ◽  
Yujing Bi ◽  
Lingling Ren ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Subunit Vaccine ◽  
Protective Efficacy ◽  
Passive Immunization ◽  
Maternal Antibodies ◽  
Newborn Mice ◽  
Content Type ◽  
Specific Antibodies ◽  
Transmission Modes ◽  
Passive Antibodies

ABSTRACTArtificially passive immunization has been demonstrated to be effective againstYersinia pestisinfection in animals. However, maternal antibodies' protective efficacy against plague has not yet been demonstrated. Here, we evaluated the kinetics, protective efficacy, and transmission modes of maternal antibodies, using mice immunized with plague subunit vaccine SV1 (20 μg of F1 and 10 μg of rV270). The results showed that the rV270- and F1-specific antibodies could be detected in the sera of newborn mice (NM) until 10 and 14 weeks of age, respectively. There was no antibody titer difference between the parturient mice immunized with SV1 (PM-S) and the caesarean-section newborns (CSN) from the PM-S or between the lactating mice immunized by SV1 (LM-S) and the cross-fostered mice (CFM) during 3 weeks of lactation. The NM had a 72% protection against 4,800 CFUY. pestisstrain 141 challenge at 6 weeks of age, whereas at 14 weeks of age, NM all succumbed to 5,700 CFU ofY. pestischallenge. After 7 weeks of age, CFM had an 84% protection against 5,000 CFU ofY. pestischallenge. These results indicated that maternal antibodies induced by the plague subunit vaccine in mother mice can be transferred to NM by both placenta and lactation. Passive antibodies from the immunized mothers could persist for 3 months and provide early protection for NM. The degree of early protection is dependent on levels of the passively acquired antibody. The results indicate that passive immunization should be an effective countermeasure against plague during its epidemics.

scholarly journals Not All Antigens Are Created Equally: Progress, Challenges, and Lessons Associated with Developing a Vaccine for Leishmaniasis

2017 ◽  
Vol 24 (7) ◽  
Author(s):  
Malcolm S. Duthie ◽  
Steven G. Reed
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Antigen Expression ◽  
Experimental Models ◽  
Vaccine Platform ◽  
Content Type ◽  
Vaccine Candidates

ABSTRACT From experimental models and the analyses of patients, it is well documented that antigen-specific T cells are critical for protection against Leishmania infection. Effective vaccines require both targeting to the pathogen and an immune stimulant to induce maturation of appropriate immune responses. While a great number of antigens have been examined as vaccine candidates against various Leishmania species, few have advanced to human or canine clinical trials. With emphasis on antigen expression, in this minireview we discuss some of the vaccine platforms that are currently being explored for the development of Leishmania vaccines. It is clear that the vaccine platform of choice can have a significant impact upon the level of protection induced by particular antigens, and we provide and highlight some examples for which the vaccine system used has impacted the protective efficacy imparted.

scholarly journals Intranasal Administration of an Inactivated Yersinia pestis Vaccine with Interleukin-12 Generates Protective Immunity against Pneumonic Plague

2011 ◽  
Vol 18 (11) ◽  
pp. 1925-1935 ◽  
Author(s):  
Devender Kumar ◽  
Girish Kirimanjeswara ◽  
Dennis W. Metzger
Keyword(s):  
Yersinia Pestis ◽  
Protective Efficacy ◽  
Bacterial Colonization ◽  
Lethal Dose ◽  
Interleukin 12 ◽  
Cell Vaccine ◽  
Mouse Serum ◽  
Immune Mouse ◽  
Pneumonic Plague ◽  
Content Type

ABSTRACTInhalation ofYersinia pestiscauses pneumonic plague, which rapidly progresses to death. A previously licensed killed whole-cell vaccine is presently unavailable due to its reactogenicity and inconclusive evidence of efficacy. The present study now shows that vaccination intranasally (i.n.) with inactivatedY. pestisCO92 (iYp) adjuvanted with interleukin-12 (IL-12) followed by an i.n. challenge with a lethal dose ofY. pestisCO92 prevented bacterial colonization and protected 100% of mice from pneumonic plague. Survival of the vaccinated mice correlated with levels of systemic and lung antibodies, reduced pulmonary pathology and proinflammatory cytokines, and the presence of lung lymphoid cell aggregates. Protection against pneumonic plague was partially dependent upon Fc receptors and could be transferred to naïve mice with immune mouse serum. On the other hand, protection was not dependent upon complement, and following vaccination, depletion of CD4 and/or CD8 T cells before challenge did not affect survival. In summary, the results demonstrate the safety, immunogenicity, and protective efficacy of i.n. administered iYp plus IL-12 in a mouse model of pneumonic plague.

scholarly journals Broadly Protective Shigella Vaccine Based on Type III Secretion Apparatus Proteins

2011 ◽  
Vol 80 (3) ◽  
pp. 1222-1231 ◽  
Author(s):  
Francisco J. Martinez-Becerra ◽  
Julian M. Kissmann ◽  
Jovita Diaz-McNair ◽  
Shyamal P. Choudhari ◽  
Amy M. Quick ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Protective Efficacy ◽  
Shigella Flexneri ◽  
Effector Proteins ◽  
High Morbidity ◽  
Content Type ◽  
Type Iii ◽  
Cellular Processes ◽  
Mucosal Antibody ◽  
Bacterial Cytoplasm

Shigellaspp. are food- and waterborne pathogens that cause severe diarrheal and dysenteric disease associated with high morbidity and mortality. Individuals most often affected are children under 5 years of age in the developing world. The existence of multipleShigellaserotypes and the heterogenic distribution of pathogenic strains, as well as emerging antibiotic resistance, require the development of a broadly protective vaccine. AllShigellaspp. utilize a type III secretion system (TTSS) to initiate infection. The type III secretion apparatus (TTSA) is the molecular needle and syringe that form the energized conduit between the bacterial cytoplasm and the host cell to transport effector proteins that manipulate cellular processes to benefit the pathogen. IpaB and IpaD form a tip complex atop the TTSA needle and are required for pathogenesis. Because they are common to all virulentShigellaspp., they are ideal candidate antigens for a subunit-based, broad-spectrum vaccine. We examined the immunogenicity and protective efficacy of IpaB and IpaD, alone or combined, coadministered with a double mutant heat-labile toxin (dmLT) fromEscherichia coli, used as a mucosal adjuvant, in a mouse model of intranasal immunization and pulmonary challenge. Robust systemic and mucosal antibody- and T cell-mediated immunities were induced against both proteins, particularly IpaB. Mice immunized in the presence of dmLT with IpaB alone or IpaB combined with IpaD were fully protected against lethal pulmonary infection withShigella flexneriandShigella sonnei. We provide the first demonstration that theShigellaTTSAs IpaB and IpaD are promising antigens for the development of a cross-protectiveShigellavaccine.

scholarly journals Redundant and Cooperative Roles for Yersinia pestis Yop Effectors in the Inhibition of Human Neutrophil Exocytic Responses Revealed by Gain-of-Function Approach

2019 ◽  
Vol 88 (3) ◽  
Author(s):  
Amanda R. Pulsifer ◽  
Aruna Vashishta ◽  
Shane A. Reeves ◽  
Jennifer K. Wolfe ◽  
Samantha G. Palace ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Effector Proteins ◽  
Host Protein ◽  
Host Cells ◽  
Function Approach ◽  
Lipid Mediator ◽  
Dependent Manner ◽  
Gain Of Function ◽  
Content Type ◽  
Type 3

ABSTRACT Yersinia pestis causes a rapid, lethal disease referred to as plague. Y. pestis actively inhibits the innate immune system to generate a noninflammatory environment during early stages of infection to promote colonization. The ability of Y. pestis to create this early noninflammatory environment is in part due to the action of seven Yop effector proteins that are directly injected into host cells via a type 3 secretion system (T3SS). While each Yop effector interacts with specific host proteins to inhibit their function, several Yop effectors either target the same host protein or inhibit converging signaling pathways, leading to functional redundancy. Previous work established that Y. pestis uses the T3SS to inhibit neutrophil respiratory burst, phagocytosis, and release of inflammatory cytokines. Here, we show that Y. pestis also inhibits release of granules in a T3SS-dependent manner. Moreover, using a gain-of-function approach, we discovered previously hidden contributions of YpkA and YopJ to inhibition and that cooperative actions by multiple Yop effectors are required to effectively inhibit degranulation. Independent from degranulation, we also show that multiple Yop effectors can inhibit synthesis of leukotriene B4 (LTB4), a potent lipid mediator released by neutrophils early during infection to promote inflammation. Together, inhibition of these two arms of the neutrophil response likely contributes to the noninflammatory environment needed for Y. pestis colonization and proliferation.

scholarly journals Enhancement of the Yersinia pestis EV NIIEG Vaccine Srain Immunogenic and Protective Activity under Cultivation with Azoxymer Bromide (Polyoxidonium)

2022 ◽  
Vol 20 (6) ◽  
pp. 12-19
Author(s):  
T. N. Shchukovskaya ◽  
A. Y. Goncharova ◽  
S. A. Bugorkova ◽  
O. M. Kudryavtseva ◽  
N. E. Shcherbakova ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Vaccine Strain ◽  
Ribosomal Proteins ◽  
Protective Efficacy ◽  
Direct Action ◽  
Serum Antibody ◽  
Live Attenuated Vaccine ◽  
Maldi Tof ◽  
Morphological Studies ◽  
Characteristic Features

Background. The live-attenuated vaccine based on the Yersinia pestis strain EV line NIIEG is still used in Russia, providing protective efficacy against plague. Nevertheless, there is an urgent need for developing new ways to increase the immunogenicity of the Y. pestis EV NIIEG vaccine strain. In this study, the ability of direct action of immunoadjuvant azoximer bromide (polyoxidonium, PO) on the immunobiological properties of vaccine strain Y. pestis EV NIIEG during cultivation on a dense nutrient medium was evaluated. Materials & Methods. Y.pestis EV NIIEG, cultivated at 28 °С for 48 h on LB agar, Miller pH 7.2 ± 0.1 (Sigma-Aldrich, USA) with the addition of PO and without. MALDI-TOF mass-spectrometry was deployed for the obtainment of mass-spectra of ribosomal proteins from Y. pestis EV NIIEG cells on the MicroflexTM LT mass spectrometer (Bruker Daltonics, Germany). Protective efficacy was evaluated under subcutaneously challenge guinea pigs and mice BALB's with 400 LD50 doses of the Y. pestis 231, Y. pestis P-13268 Vietnam (MLD=5 CFU). Antibody titers to F1 in serum were determined using an ELISA. Results. The addition of the therapeutic concentration of PO in the cultivation medium induced a significant increase in the immunogenicity of Y. pestis EV NIIEG that resulted in enhancement of serum antibody levels against Y. pestis F1 antigen and several times the growth of protective efficacy in the bubonic plague model on two types of experimental animals. ImD50 of the vaccine strain Y. pestis EV NIIEG, cultivated with PO, was significantly (p < 0,05) lower in comparison to ImD50 for Y. pestis EV NIIEG in standard cultivation conditions. One year of storage at a temperature of 4 °С did not alter the protective properties of the vaccine strain Y. pestis EV NIIEG, cultivated with PO. Conclusions. Morphological studies confirmed the absence of influence PO introduction into the cultivation environment on the safety of the vaccine strain. MALDI-TOF MS profile of the Y. pestis EV NIIEG, cultivated with PO, had peaks characteristic features. The mass peak at m/z 3,061 was significantly down-regulated and new mass peaks at m/z 2,759, m/z 3,533 were determined. These changes are accompanied by the increase of Y. pestis EV NIIEG immunogenicity.

scholarly journals Mucosal Influenza Vector Vaccine Carrying TB10.4 and HspX Antigens Provides Protection against Mycobacterium tuberculosis in Mice and Guinea Pigs

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 394
Author(s):  
Mariia Sergeeva ◽  
Ekaterina Romanovskaya-Romanko ◽  
Natalia Zabolotnyh ◽  
Anastasia Pulkina ◽  
Kirill Vasilyev ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Vaccine Candidate ◽  
Cell Immune Response ◽  
Lung Pathology ◽  
Ns1 Protein ◽  
Reading Frame ◽  
Intranasal Immunization ◽  
Vector Vaccine ◽  
Boost Immunization ◽  
New Strategies

New strategies providing protection against tuberculosis (TB) are still pending. The airborne nature of Mycobacterium tuberculosis (M.tb) infection assumes that the mucosal delivery of the TB vaccine could be a more promising strategy than the systemic route of immunization. We developed a mucosal TB vaccine candidate based on recombinant attenuated influenza vector (Flu/THSP) co-expressing truncated NS1 protein NS1(1–124) and a full-length TB10.4 and HspX proteins of M.tb within an NS1 protein open reading frame. The Flu/THSP vector was safe and stimulated a systemic TB-specific CD4+ and CD8+ T-cell immune response after intranasal immunization in mice. Double intranasal immunization with the Flu/THSP vector induced protection against two virulent M.tb strains equal to the effect of BCG subcutaneous injection in mice. In a guinea pig TB model, one intranasal immunization with Flu/THSP improved protection against M.tb when tested as a vaccine candidate for boosting BCG-primed immunity. Importantly, enhanced protection provided by a heterologous BCG-prime → Flu/THSP vector boost immunization scheme was associated with a significantly reduced lung and spleen bacterial burden (mean decrease of 0.77 lg CFU and 0.72 lg CFU, respectively) and improved lung pathology 8.5 weeks post-infection with virulent M.tb strain H37Rv.

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