scholarly journals A Recombinant Attenuated Salmonella enterica Serovar Typhimurium Vaccine Encoding Eimeria acervulina Antigen Offers Protection against E. acervulina Challenge

2006 ◽  
Vol 74 (12) ◽  
pp. 6785-6796 ◽  
Author(s):  
Vjollca Konjufca ◽  
Soo-Young Wanda ◽  
Mark C. Jenkins ◽  
Roy Curtiss

ABSTRACT Coccidiosis is a ubiquitous disease caused by intestinal protozoan parasites belonging to several distinct species of the genus Eimeria. Cell-mediated immunity (CMI) is critically important for protection against Eimeria; thus, our approach utilizes the bacterial type III secretion system (TTSS) to deliver an antigen directly into the cell cytoplasm of the immunized host and into the major histocompatibility complex class I antigen-processing pathway for induction of CMI and antigen-specific cytotoxic T-lymphocyte responses in particular. To accomplish this goal, Eimeria genes encoding the sporozoite antigen EASZ240 and the merozoite antigen EAMZ250 were fused to the Salmonella enterica serovar Typhimurium effector protein gene sptP in the parental pYA3653 vector, yielding pYA3657 and pYA3658, respectively. SptP protein is secreted by the TTSS of Salmonella and translocated into the cytoplasm of immunized host cells. The host strain chromosomal copy of the sptP gene was deleted and replaced by a reporter gene, xylE. The newly constructed vectors pYA3657 and pYA3658 were introduced into host strain χ8879 (ΔphoP233 ΔsptP1033::xylEΔ asdA16). This strain is an attenuated derivative of the highly virulent strain UK-1. When strain χ8879(pYA3653) as the vector control and strain χ8879 harboring pYA3657 or pYA3658 were used to orally immunize day-of-hatch chicks, colonization of the bursa, spleen, and liver was observed, with peak titers 6 to 9 days postimmunization. In vitro experiments show that the EASZ240 antigen is secreted into the culture supernatant via the TTSS and that it is delivered into the cytoplasm of Int-407 cells by the TTSS. In vivo experiments indicate that both humoral and cell-mediated immune responses are induced in chickens vaccinated with a recombinant attenuated Salmonella serovar Typhimurium vaccine, which leads to significant protection against Eimeria challenge.

2001 ◽  
Vol 69 (12) ◽  
pp. 7413-7418 ◽  
Author(s):  
Tahar van der Straaten ◽  
Angela van Diepen ◽  
Kitty Kwappenberg ◽  
Sjaak van Voorden ◽  
Kees Franken ◽  
...  

ABSTRACT Upon contact with host cells, the intracellular pathogenSalmonella enterica serovar Typhimurium promotes its uptake, targeting, and survival in intracellular niches. In this process, the bacterium evades the microbicidal effector mechanisms of the macrophage, including oxygen intermediates. This study reports the phenotypic and genotypic characterization of an S. enterica serovar Typhimurium mutant that is hypersusceptible to superoxide. The susceptible phenotype is due to a MudJ insertion-inactivation of a previously undescribedSalmonella gene designated sspJ that is located between 54.4 and 64 min of the Salmonellachromosome and encodes a 392-amino-acid protein. In vivo, upon intraperitoneal injection of 104 to 107bacteria in C3H/HeN and 101 to 104 bacteria in BALB/c mice, the mutant strain was less virulent than the wild type. Consistent with this finding, during the first hour after ingestion by macrophage-like J774 and RAW264.7 cells in vitro, the intracellular killing of the strain carrying sspJ::MudJ is enhanced fivefold over that of wild-type microorganisms. Wild-type salmonellae displayed significant intracellular replication during the first 24 h after uptake, but sspJ::MudJ mutants failed to do so. This phenotype could be restored to that of the wild type by sspJ complementation. The SspJ protein is found in the cytoplasmic membrane and periplasmic space. Amino acid sequence homology analysis did reveal a leader sequence and putative pyrroloquinoline quinone-binding domains, but no putative protein function. We excluded the possibility that SspJ is a scavenger of superoxide or has superoxide dismutase activity.


2013 ◽  
Vol 81 (6) ◽  
pp. 1952-1963 ◽  
Author(s):  
Michael D. Lovelace ◽  
May Lin Yap ◽  
Jana Yip ◽  
William Muller ◽  
Odilia Wijburg ◽  
...  

ABSTRACTPECAM-1/CD31 is known to regulate inflammatory responses and exhibit pro- and anti-inflammatory functions. This study was designed to determine the functional role of PECAM-1 in susceptibility to murine primaryin vivoinfection withSalmonella entericaserovar Typhimurium and inin vitroinflammatory responses of peritoneal macrophages. Lectin profiling showed that cellular PECAM-1 and recombinant human PECAM-1-Ig chimera contain high levels of mannose sugars andN-acetylglucosamine. Consistent with this carbohydrate pattern, both recombinant human and murine PECAM-1-Ig chimeras were shown to bindS. Typhimurium in a dose-dependent mannerin vitro. Using oral and fecal-oral transmission models ofS. Typhimurium SL1344 infection, PECAM-1−/−mice were found to be more resistant toS. Typhimurium infection than wild-type (WT) C57BL/6 mice. While fecal shedding ofS. Typhimurium was comparable in wild-type and PECAM-1−/−mice, the PECAM-1-deficient mice had lower bacterial loads in systemic organs such as liver, spleen, and mesenteric lymph nodes than WT mice, suggesting that extraintestinal dissemination was reduced in the absence of PECAM-1. This reduced bacterial load correlated with reduced tumor necrosis factor (TNF), interleukin-6 (IL-6), and monocyte chemoattractant protein (MCP) levels in sera of PECAM-1−/−mice. Followingin vitrostimulation of macrophages with either wholeS. Typhimurium, lipopolysaccharide (LPS) (Toll-like receptor 4 [TLR4] ligand), or poly(I·C) (TLR3 ligand), production of TNF and IL-6 by PECAM-1−/−macrophages was reduced. Together, these results suggest that PECAM-1 may have multiple functions in resistance to infection withS. Typhimurium, including binding to host cells, extraintestinal spread to deeper tissues, and regulation of inflammatory cytokine production by infected macrophages.


2005 ◽  
Vol 73 (2) ◽  
pp. 1081-1096 ◽  
Author(s):  
A. A. Fadl ◽  
J. Sha ◽  
G. R. Klimpel ◽  
J. P. Olano ◽  
D. W. Niesel ◽  
...  

ABSTRACT Lipopolysaccharide (LPS) and Braun (murein) lipoprotein (Lpp) are major components of the outer membrane of gram-negative enteric bacteria that function as potent stimulators of inflammatory and immune responses. In a previous paper, we provided evidence that two functional copies of the lipoprotein gene (lppA and lppB) located on the chromosome of Salmonella enterica serovar Typhimurium contributed to bacterial virulence. In this study, we characterized lppA and lppB single-knockout (SKO) mutants and compared them with an lpp double-knockout (DKO) mutant using in vitro and in vivo models. Compared to the lpp DKO mutant, which was nonmotile, the motility of the lpp SKO mutants was significantly increased (73 to 77%), although the level of motility did not reach the level of wild-type (WT) S. enterica serovar Typhimurium. Likewise, the cytotoxicity was also significantly increased when T84 human intestinal epithelial cells and RAW264.7 murine macrophages were infected with the lpp SKO mutants compared to the cytotoxicity when cells were infected with the lpp DKO mutant. The level of interleukin-8 (IL-8) in polarized T84 cells infected with the lppB SKO mutant was significantly higher (two- to threefold higher), reaching the level in cells infected with WT S. enterica serovar Typhimurium, than the level in host cells infected with the lppA SKO mutant. The lpp DKO mutant induced minimal levels of IL-8. Similarly, sera from mice infected with the lppB SKO mutant contained 4.5- to 10-fold-higher levels of tumor necrosis factor-α and IL-6; the levels of these cytokines were 1.7- to 3.0-fold greater in the lppA SKO mutant-infected mice than in animals challenged with the lpp DKO mutant. The increased cytokine levels observed with the lppB SKO mutant in mice correlated with greater tissue damage in the livers and spleens of these mice than in the organs of animals infected with the lppA SKO and lpp DKO mutants. Moreover, the lppB SKO mutant-infected mice had increased susceptibility to death. Since the lpp DKO mutant retained intact LPS, we constructed an S. enterica serovar Typhimurium triple-knockout (TKO) mutant in which the lppA and lppB genes were deleted from an existing msbB mutant (msbB encodes an enzyme required for the acylation of lipid A). Compared to the lpp DKO and msbB SKO mutants, the lpp-msbB TKO mutant was unable to induce cytotoxicity and to produce cytokines and chemokines in vitro and in vivo. These studies provided the first evidence of the relative contributions of Lpp and lipid A acylation to Salmonella pathogenesis.


2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Vivek Belde ◽  
Matthew P. Cravens ◽  
Dania Gulandijany ◽  
Justin A. Walker ◽  
Isabel Palomo-Caturla ◽  
...  

ABSTRACTB cell antigen receptor (BCR) diversity increases by several orders of magnitude due to the action of terminal deoxynucleotidyl transferase (TdT) during V(D)J recombination. Unlike adults, infants have limited BCR diversity, in part due to reduced expression of TdT. Since human infants and young mice respond poorly to polysaccharide vaccines, such as the pneumococcal polysaccharide vaccine Pneumovax23 and Vi polysaccharide (ViPS) ofSalmonella entericaserovar Typhi, we tested the contribution of TdT-mediated BCR diversity in response to these vaccines. We found that TdT+/−and TdT−/−mice generated comparable antibody responses to Pneumovax23 and survivedStreptococcus pneumoniaechallenge. Moreover, passive immunization of B cell-deficient mice with serum from Pneumovax23-immunized TdT+/−or TdT−/−mice conferred protection. TdT+/−and TdT−/−mice generated comparable levels of anti-ViPS antibodies and antibody-dependent, complement-mediated bactericidal activity againstS. Typhiin vitro. To test the protective immunity conferred by ViPS immunizationin vivo, TdT+/−and TdT−/−mice were challenged with a chimericSalmonella entericaserovar Typhimurium strain expressing ViPS, since mice are nonpermissive hosts forS. Typhi infection. Compared to their unimmunized counterparts, immunized TdT+/−and TdT−/−mice challenged with ViPS-expressingS. Typhimurium exhibited a significant reduction in the bacterial burden and liver pathology. These data suggest that the impaired antibody response to the Pneumovax23 and ViPS vaccines in the young is not due to limited TdT-mediated BCR diversification.


2005 ◽  
Vol 73 (12) ◽  
pp. 8433-8436 ◽  
Author(s):  
A. A. Fadl ◽  
J. Sha ◽  
G. R. Klimpel ◽  
J. P. Olano ◽  
C. L. Galindo ◽  
...  

ABSTRACT We constructed Salmonella enterica serovar Typhimurium double-knockout mutants in which either the lipoprotein A (lppA) or the lipoprotein B (lppB) gene was deleted from an msbB-negative background strain by marker exchange mutagenesis. These mutants were highly attenuated when tested with in vitro and in vivo models of Salmonella pathogenesis.


2004 ◽  
Vol 186 (16) ◽  
pp. 5230-5238 ◽  
Author(s):  
Radha Krishnakumar ◽  
Maureen Craig ◽  
James A. Imlay ◽  
James M. Slauch

ABSTRACT Salmonella enterica serovar Typhimurium produces two Cu/Zn cofactored periplasmic superoxide dismutases, SodCI and SodCII. While mutations in sodCI attenuate virulence eightfold, loss of SodCII does not confer a virulence phenotype, nor does it enhance the defect observed in a sodCI background. Despite this in vivo phenotype, SodCI and SodCII are expressed at similar levels in vitro during the stationary phase of growth. By exchanging the open reading frames of sodCI and sodCII, we found that SodCI contributes to virulence when placed under the control of the sodCII promoter. In contrast, SodCII does not contribute to virulence even when expressed from the sodCI promoter. Thus, the disparity in virulence phenotypes is due primarily to some physical difference between the two enzymes. In an attempt to identify the unique property of SodCI, we have tested factors that might affect enzyme activity inside a phagosome. We found no significant difference between SodCI and SodCII in their resistance to acid, resistance to hydrogen peroxide, or ability to obtain copper in a copper-limiting environment. Both enzymes are synthesized as apoenzymes in the absence of copper and can be fully remetallated when copper is added. The one striking difference that we noted is that, whereas SodCII is released normally by an osmotic shock, SodCI is “tethered” within the periplasm by an apparently noncovalent interaction. We propose that this novel property of SodCI is crucial to its ability to contribute to virulence in serovar Typhimurium.


2001 ◽  
Vol 69 (7) ◽  
pp. 4673-4677 ◽  
Author(s):  
Chris A. Allen ◽  
Paula J. Fedorka-Cray ◽  
Andrés Vazquez-Torres ◽  
Mitsu Suyemoto ◽  
Craig Altier ◽  
...  

ABSTRACT Multidrug-resistant Salmonella enterica serovar Typhimurium phage type DT104 has become a widespread cause of human and other animal infection worldwide. The severity of clinical illness inS. enterica serovar Typhimurium DT104 outbreaks has led to the suggestion that this strain possesses enhanced virulence. In the present study, in vitro and in vivo virulence-associated phenotypes of several clinical isolates of S. enterica serovar Typhimurium DT104 were examined and compared to S. entericaserovar Typhimurium ATCC 14028s. The ability of these DT104 isolates to survive within murine peritoneal macrophages, invade cultured epithelial cells, resist antimicrobial actions of reactive oxygen and nitrogen compounds, and cause lethal infection in mice were assessed. Our results failed to demonstrate that S. enterica serovar Typhimurium DT104 isolates are more virulent than S. enterica serovar Typhimurium ATCC 14028s.


2009 ◽  
Vol 78 (3) ◽  
pp. 914-926 ◽  
Author(s):  
Cristiano G. Moreira ◽  
David Weinshenker ◽  
Vanessa Sperandio

ABSTRACT The autoinducer-3 (AI-3)/epinephrine (Epi)/norepinephrine (NE) interkingdom signaling system mediates chemical communication between bacteria and their mammalian hosts. The three signals are sensed by the QseC histidine kinase (HK) sensor. Salmonella enterica serovar Typhimurium is a pathogen that uses HKs to sense its environment and regulate virulence. Salmonella serovar Typhimurium invades epithelial cells and survives within macrophages. Invasion of epithelial cells is mediated by the type III secretion system (T3SS) encoded in Salmonella pathogenicity island 1 (SPI-1), while macrophage survival and systemic disease are mediated by the T3SS encoded in SPI-2. Here we show that QseC plays an important role in Salmonella serovar Typhimurium pathogenicity. A qseC mutant was impaired in flagellar motility, in invasion of epithelial cells, and in survival within macrophages and was attenuated for systemic infection in 129x1/SvJ mice. QseC acts globally, regulating expression of genes within SPI-1 and SPI-2 in vitro and in vivo (during infection of mice). Additionally, dopamine β-hydroxylase knockout (Dbh − / −) mice that do not produce Epi or NE showed different susceptibility to Salmonella serovar Typhimurium infection than wild-type mice. These data suggest that the AI-3/Epi/NE signaling system is a key factor during Salmonella serovar Typhimurium pathogenesis in vitro and in vivo. Elucidation of the role of this interkingdom signaling system in Salmonella serovar Typhimurium should contribute to a better understanding of the complex interplay between the pathogen and the host during infection.


2002 ◽  
Vol 70 (4) ◽  
pp. 1997-2009 ◽  
Author(s):  
Giovanna Sebastiani ◽  
Véronique Blais ◽  
Vanessa Sancho ◽  
Stefanie N. Vogel ◽  
Mary M. Stevenson ◽  
...  

ABSTRACT Studies of mouse models of endotoxemia and sepsis with gram-negative bacteria have shown that the host response is genetically controlled. Mice infected with the gram-negative bacterium Salmonella enterica serovar Typhimurium exhibit marked genetic differences in disease manifestation, and the wild-derived strain Mus musculus molossinus MOLF/Ei is extremely susceptible to S. enterica serovar Typhimurium. The kinetics of bacterial proliferation within the liver and the spleen and histological examination of tissue sections have suggested that MOLF/Ei mice do not succumb to infection because of overwhelming bacterial growth in the reticuloendothelial organs or massive tissue necrosis, as observed in other Salmonella-susceptible strains. MOLF/Ei mice respond normally to lipopolysaccharide (LPS) in vivo and in vitro, as determined by the production of tumor necrosis factor alpha and spleen cell mitogenesis. However, they have a unique cytokine profile in response to infection compared to that observed for other Salmonella-susceptible mice. There was increased expression of mRNA of the interleukin-1α (IL-1α) and IL-1β genes as the infection in the spleens and livers of MOLF/Ei mice progressed. Despite the fact that MOLF/Ei mice have the ability to respond to LPS and the fact that there are significant increases in IL-1α and IL-1β mRNA, Nos2 in the spleen is not upregulated and nitrite production by spleen cells is reduced. At the central level, the inflammatory response is characterized by strong upregulation of the inhibitory factor kappa B alpha and Toll-like receptor 2 genes, two genes known to be regulated by LPS and IL-1 in the brain. The high levels of IL-1 expression in the spleens and livers of MOLF/Ei mice may have important implications for the activation of peripheral and central innate immune mechanisms.


2002 ◽  
Vol 184 (15) ◽  
pp. 4148-4160 ◽  
Author(s):  
Igor N. Olekhnovich ◽  
Robert J. Kadner

ABSTRACT The HilC and HilD proteins of Salmonella enterica serovar Typhimurium are members of the AraC/XylS family of transcription regulators. They are encoded on Salmonella pathogenicity island 1 (SPI1) and control expression of the hilA gene, which encodes the major transcriptional activator for many genes encoded on SPI1 and elsewhere that contribute to invasion of host cells. Gel electrophoretic shift and DNase footprinting assays revealed that purified HilC and HilD proteins can bind to multiple regions in the hilA and hilC promoters and to a single region in the hilD promoter. Although both HilC and -D proteins can bind to the same DNA regions, they showed different dependencies on the sequence and lengths of their DNA targets. To identify the binding-sequence specificity of HilC and HilD, a series of single base substitutions changing each position in a DNA fragment corresponding to positions −92 to −52 of the hilC promoter was tested for binding to HilC and HilD in a gel shift DNA-binding assay. This mutational analysis in combination with sequence alignments allowed deduction of consensus sequences for binding of both proteins. The consensus sequences overlap but differ so that HilC can bind to both types of sites but HilD only to one. The hilA and hilC promoters contain multiple binding sites of each type, whereas the hilD promoter contains a site that binds HilC but not HilD without additional binding elements. The HilC and HilD proteins had no major effect on transcription from the hilA or hilD promoters using purified proteins in vitro but changed the choice of promoter at hilC. These results are consistent with a model derived from analysis of lacZ fusions stating that HilC and HilD enhance hilA expression by counteracting a repressing activity.


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