scholarly journals Safety of a Novel Listeria monocytogenes-Based Vaccine Vector Expressing NcSAG1 (Neospora caninum Surface Antigen 1)

2021 ◽  
Vol 11 ◽  
Author(s):  
William Robert Pownall ◽  
Dennis Imhof ◽  
Nerea Fernandez Trigo ◽  
Stephanie C. Ganal-Vonarburg ◽  
Philippe Plattet ◽  
...  
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Adverse Effects ◽  
Surface Antigen ◽  
Neospora Caninum ◽  
Bacterial Load ◽  
Vaccine Vector ◽  
Physiological Status ◽  
Strong Immune Response

Listeria monocytogenes (LM) has been proposed as vaccine vector in various cancers and infectious diseases since LM induces a strong immune response. In this study, we developed a novel and safe LM-based vaccine vector platform, by engineering a triple attenuated mutant (Lm3Dx) (ΔactA, ΔinlA, ΔinlB) of the wild-type LM strain JF5203 (CC 1, phylogenetic lineage I). We demonstrated the strong attenuation of Lm3Dx while maintaining its capacity to selectively infect antigen-presenting cells (APCs) in vitro. Furthermore, as proof of concept, we introduced the immunodominant Neospora caninum (Nc) surface antigen NcSAG1 into Lm3Dx. The NcSAG1 protein was expressed by Lm3Dx_SAG1 during cellular infection. To demonstrate safety of Lm3Dx_SAG1 in vivo, we vaccinated BALB/C mice by intramuscular injection. Following vaccination, mice did not suffer any adverse effects and only sporadically shed bacteria at very low levels in the feces (<100 CFU/g). Additionally, bacterial load in internal organs was very low to absent at day 1.5 and 4 following the 1st vaccination and at 2 and 4 weeks after the second boost, independently of the physiological status of the mice. Additionally, vaccination of mice prior and during pregnancy did not interfere with pregnancy outcome. However, Lm3Dx_SAG1 was shed into the milk when inoculated during lactation, although it did not cause any clinical adverse effects in either dams or pups. Also, we have indications that the vector persists more days in the injected muscle of lactating mice. Therefore, impact of physiological status on vector dynamics in the host and mechanisms of milk shedding requires further investigation. In conclusion, we provide strong evidence that Lm3Dx is a safe vaccine vector in non-lactating animals. Additionally, we provide first indications that mice vaccinated with Lm3Dx_SAG1 develop a strong and Th1-biased immune response against the Lm3Dx-expressed neospora antigen. These results encourage to further investigate the efficiency of Lm3Dx_SAG1 to prevent and treat clinical neosporosis.

scholarly journals Induction of Human Immunodeficiency Virus (HIV)-Specific CD8 T-Cell Responses by Listeria monocytogenes and a Hyperattenuated Listeria Strain Engineered To Express HIV Antigens

2000 ◽  
Vol 74 (21) ◽  
pp. 9987-9993 ◽  
Author(s):  
Rachel S. Friedman ◽  
Fred R. Frankel ◽  
Zhan Xu ◽  
Judy Lieberman
Keyword(s):  
Human Immunodeficiency Virus ◽  
Listeria Monocytogenes ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Immunity ◽  
Vaccine Vector ◽  
Cell Immunity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Induction of cell-mediated immunity may be essential for an effective AIDS vaccine. Listeria monocytogenes is an attractive bacterial vector to elicit T-cell immunity to human immunodeficiency virus (HIV) because it specifically infects monocytes, key antigen-presenting cells, and because natural infection originates at the mucosa. Immunization with recombinant L. monocytogenes has been shown to protect mice from lymphocytic choriomeningitis virus, influenza virus, and tumor inoculation.L. monocytogenes expressing HIV gag elicits sustained high levels of Gag-specific cytotoxic T lymphocytes (CTLs) in mice. We have examined the ability of Listeria to infect human monocytes and present HIV antigens to CD8 T lymphocytes of HIV-infected donors to induce a secondary T-cell immune response. Using this in vitro vaccination protocol, we show that L. monocytogenes expressing the HIV-1 gag gene efficiently provides a strong stimulus for Gag-specific CTLs in HIV-infected donor peripheral blood mononuclear cells.Listeria expressing Nef also elicits a secondary in vitro anti-Nef CTL response. Since L. monocytogenes is a pathogen, before it can be seriously considered as a human vaccine vector, safety concerns must be addressed. We therefore have produced a highly attenuated strain of L. monocytogenes that requiresd-alanine for viability. The recombinant bacteria are attenuated at least 105-fold. We show that when these hyperattenuated bacteria are engineered to express HIV-1 Gag, they are at least as efficient at stimulating Gag-specific human CTLs in vitro as wild-type recombinants. These results suggest that attenuatedListeria is an attractive candidate vaccine vector to induce T-cell immunity to HIV in humans.

scholarly journals Listeria monocytogenes Spreads within the Brain by Actin-Based Intra-Axonal Migration

2015 ◽  
Vol 83 (6) ◽  
pp. 2409-2419 ◽  
Author(s):  
Diana Henke ◽  
Sebastian Rupp ◽  
Véronique Gaschen ◽  
Michael H. Stoffel ◽  
Joachim Frey ◽  
...  
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Brain Cell ◽  
Bovine Brain ◽  
Content Type ◽  
Bacterial Migration ◽  
Bacterial Replication ◽  
The Brain

Listeria monocytogenesrhombencephalitis is a severe progressive disease despite a swift intrathecal immune response. Based on previous observations, we hypothesized that the disease progresses by intra-axonal spread within the central nervous system. To test this hypothesis, neuroanatomical mapping of lesions, immunofluorescence analysis, and electron microscopy were performed on brains of ruminants with naturally occurring rhombencephalitis. In addition, infection assays were performed in bovine brain cell cultures. Mapping of lesions revealed a consistent pattern with a preferential affection of certain nuclear areas and white matter tracts, indicating thatListeria monocytogenesspreads intra-axonally within the brain along interneuronal connections. These results were supported by immunofluorescence and ultrastructural data localizingListeria monocytogenesinside axons and dendrites associated with networks of fibrillary structures consistent with actin tails.In vitroinfection assays confirmed that bacteria were moving within axon-like processes by employing their actin tail machinery. Remarkably,in vivo, neutrophils invaded the axonal space and the axon itself, apparently by moving between split myelin lamellae of intact myelin sheaths. This intra-axonal invasion of neutrophils was associated with various stages of axonal degeneration and bacterial phagocytosis. Paradoxically, the ensuing adaxonal microabscesses appeared to provide new bacterial replication sites, thus supporting further bacterial spread. In conclusion, intra-axonal bacterial migration and possibly also the innate immune response play an important role in the intracerebral spread of the agent and hence the progression of listeric rhombencephalitis.

scholarly journals Cytolysin-Dependent Escape of the Bacterium from the Phagosome Is Required but Not Sufficient for Induction of the Th1 Immune Response against Listeria monocytogenes Infection: Distinct Role of Listeriolysin O Determined by Cytolysin Gene Replacement

2007 ◽  
Vol 75 (8) ◽  
pp. 3791-3801 ◽  
Author(s):  
Hideki Hara ◽  
Ikuo Kawamura ◽  
Takamasa Nomura ◽  
Takanari Tominaga ◽  
Kohsuke Tsuchiya ◽  
...  
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Virulence Factor ◽  
Protective Immunity ◽  
Gene Replacement ◽  
Listeriolysin O ◽  
Listeria Ivanovii ◽  
Ifn Γ

ABSTRACT Listeria monocytogenes evades the antimicrobial mechanisms of macrophages by escaping from the phagosome into the cytosolic space via a unique cytolysin that targets the phagosomal membrane, listeriolysin O (LLO), encoded by hly. Gamma interferon (IFN-γ), which is known to play a pivotal role in the induction of Th1-dependent protective immunity in mice, appears to be produced, depending on the bacterial virulence factor. To determine whether the LLO molecule (the major virulence factor of L. monocytogenes) is indispensable or the escape of bacteria from the phagosome is sufficient to induce IFN-γ production, we first constructed an hly-deleted mutant of L. monocytogenes and then established isogenic L. monocytogenes mutants expressing LLO or ivanolysin O (ILO), encoded by ilo from Listeria ivanovii. LLO-expressing L. monocytogenes was highly capable of inducing IFN-γ production and Listeria-specific protective immunity, while the hly-deleted mutant was not. In contrast, the level of IFN-γ induced by ILO-expressing L. monocytogenes was significantly lower both in vitro and in vivo, despite the ability of this strain to escape the phagosome and the intracellular multiplication at a level equivalent to that of LLO-expressing L. monocytogenes. Only a negligible level of protective immunity was induced in mice against challenge with LLO- and ILO-expressing L. monocytogenes. These results clearly show that escape of the bacterium from the phagosome is a prerequisite but is not sufficient for the IFN-γ-dependent Th1 response against L. monocytogenes, and some distinct molecular nature of LLO is indispensable for the final induction of IFN-γ that is essentially required to generate a Th1-dependent immune response.

scholarly journals Development of a Conserved Chimeric Vaccine for Induction of Strong Immune Response against Staphylococcus aureus Using Immunoinformatics Approaches

Vaccines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1038
Author(s):  
Rahul Chatterjee ◽  
Panchanan Sahoo ◽  
Soumya Ranjan Mahapatra ◽  
Jyotirmayee Dey ◽  
Mrinmoy Ghosh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Response ◽  
Multidrug Resistant ◽  
Host Cells ◽  
Dynamics Simulation ◽  
Population Coverage ◽  
Strong Immune Response ◽  
Chimeric Vaccine

Staphylococcus aureus is one of the most notorious Gram-positive bacteria with a very high mortality rate. The WHO has listed S. aureus as one of the ESKAPE pathogens requiring urgent research and development efforts to fight against it. Yet there is a major layback in the advancement of effective vaccines against this multidrug-resistant pathogen. SdrD and SdrE proteins are attractive immunogen candidates as they are conserved among all the strains and contribute specifically to bacterial adherence to the host cells. Furthermore, these proteins are predicted to be highly antigenic and essential for pathogen survival. Therefore, in this study, using the immunoinformatics approach, a novel vaccine candidate was constructed using highly immunogenic conserved T-cell and B-cell epitopes along with specific linkers, adjuvants, and consequently modeled for docking with human Toll-like receptor 2. Additionally, physicochemical properties, secondary structure, disulphide engineering, and population coverage analysis were also analyzed for the vaccine. The constructed vaccine showed good results of worldwide population coverage and a promising immune response. For evaluation of the stability of the vaccine-TLR-2 docked complex, a molecular dynamics simulation was performed. The constructed vaccine was subjected to in silico immune simulations by C-ImmSim and Immune simulation significantly provided high levels of immunoglobulins, T-helper cells, T-cytotoxic cells, and INF-γ. Lastly, upon cloning, the vaccine protein was reverse transcribed into a DNA sequence and cloned into a pET28a (+) vector to ensure translational potency and microbial expression. The overall results of the study showed that the designed novel chimeric vaccine can simultaneously elicit humoral and cell-mediated immune responses and is a reliable construct for subsequent in vivo and in vitro studies against the pathogen.

scholarly journals The Systemic and Cellular Metabolic Phenotype of Infection and Immune Response to Listeria monocytogenes

2021 ◽  
Vol 11 ◽  
Author(s):  
Robert M. Johnson ◽  
Adesola C. Olatunde ◽  
Lauren N. Woodie ◽  
Michael W. Greene ◽  
Elizabeth Hiltbold Schwartz
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
T Cell ◽  
Immune Responses ◽  
Metabolic Pathways ◽  
Bacterial Load ◽  
Cellular Level ◽  
Metabolic Phenotype ◽  
Infection Model ◽  
Cell Mediated Immunity

It is widely accepted that infection and immune response incur significant metabolic demands, yet the respective demands of specific immune responses to live pathogens have not been well delineated. It is also established that upon activation, metabolic pathways undergo shifts at the cellular level. However, most studies exploring these issues at the systemic or cellular level have utilized pathogen associated molecular patterns (PAMPs) that model sepsis, or model antigens at isolated time points. Thus, the dynamics of pathogenesis and immune response to a live infection remain largely undocumented. To better quantitate the metabolic demands induced by infection, we utilized a live pathogenic infection model. Mice infected with Listeria monocytogenes were monitored longitudinally over the course of infection through clearance. We measured systemic metabolic phenotype, bacterial load, innate and adaptive immune responses, and cellular metabolic pathways. To further delineate the role of adaptive immunity in the metabolic phenotype, we utilized two doses of bacteria, one that induced both sickness behavior and protective (T cell mediated) immunity, and the other protective immunity alone. We determined that the greatest impact to systemic metabolism occurred during the early immune response, which coincided with the greatest shift in innate cellular metabolism. In contrast, during the time of maximal T cell expansion, systemic metabolism returned to resting state. Taken together, our findings demonstrate that the timing of maximal metabolic demand overlaps with the innate immune response and that when the adaptive response is maximal, the host has returned to relative metabolic homeostasis.

scholarly journals Immunization of BALB/c Mice with Killed Neospora caninum Tachyzoite Antigen Induces a Type 2 Immune Response and Exacerbates Encephalitis and Neurological Disease

2000 ◽  
Vol 7 (6) ◽  
pp. 893-898 ◽  
Author(s):  
Timothy V. Baszler ◽  
Terry F. McElwain ◽  
Bruce A. Mathison
Keyword(s):  
Immune Response ◽  
Neurological Disease ◽  
Neospora Caninum ◽  
Brain Lesions ◽  
Lymphoid Cells ◽  
Interleukin 4 ◽  
Type 2 Immune Response ◽  
Parasite Challenge

ABSTRACT BALB/c mice were immunized subcutaneously with solubleNeospora caninum tachyzoite antigen (NSO) entrapped in nonionic surfactant vesicles (NISVs) or administered with Freund's complete adjuvant (FCA). Following virulent parasite challenge, groups of mice immunized with NSO and either NISVs or FCA had clinical neurological disease and increased numbers of brain lesions compared to groups of mice inoculated with FCA, NISVs, or phosphate-buffered saline (PBS) alone. Increased numbers of brain lesions were statistically significant only between mice immunized with NISV-NSO and NISV- or PBS-treated mice. Following parasite challenge, brain inflammatory infiltrates in all experimental and control groups of mice were relatively similar and consisted of compact infiltrates of macrophages admixed with various numbers of lymphoid cells. Increased brain lesions in NSO-immunized mice were associated with increased antigen-specific interleukin 4 (IL-4) secretion and increased IL-4:gamma interferon secretion ratios from splenocytes in vitro and increased antigen-specific immunoglobulin G1 (IgG1):IgG2a ratios in vivo. Thus, immunization with whole killed N. caninum antigen and either liposoidal or Freund's adjuvant induced a type 2 immune response that was associated with worsened disease. The present studies emphasize the need to identify specific N. caninum antigens or other delivery systems that will elicit protective immune responses to neosporosis.

scholarly journals Mimicry of the a determinant of hepatitis B surface antigen by an antiidiotypic antibody. I. Evaluation in hepatitis B surface antigen responder and nonresponder strains.

1993 ◽  
Vol 177 (1) ◽  
pp. 127-134 ◽  
Author(s):  
M W Pride ◽  
A Thakur ◽  
Y Thanavala
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Lymph Node ◽  
T Cell ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Hepatitis B Surface Antigen ◽  
T Cell Response

B and T cell responses of several strains of mice, immunized with a monoclonal antiidiotype (anti-Id) that mimics the a determinant of hepatitis B surface antigen (HBsAg), were studied to determine if the immune response to the anti-Id was regulated by H-2-linked immune response genes as has been previously observed for HBsAg. We report that immunization with anti-Id could elicit HBsAg-specific antibodies in mice of the H-2d,q, or f haplotype and in an outbred wild mouse strain (Mus spretus), thus circumventing the H-2 haplotype restriction pattern observed when immunizing with HBsAg in H-2f mice. Purified lymph node T cells from mice of the H-2d or q haplotype and M. spretus that were primed in vivo with HBsAg or anti-Id could be stimulated in vitro with either HBsAg or anti-Id but not with an irrelevant antibody of the same subclass as the anti-Id. However, purified lymph node T cells from H-2f mice that were primed in vivo with the anti-Id could only be stimulated in vitro with anti-Id. No in vitro stimulation whatsoever was observed in H-2f mice immunized with HBsAg. The effect of processing and presentation of the anti-Id by antigen-presenting cells (APC) was studied in mice of the H-2d haplotype. Stimulation of purified lymph node T cells by HBsAg and anti-Id was shown to be strictly dependent on APC and restricted by major histocompatibility complex class II antigens at the I-A locus. Treatment of APC with paraformaldehyde or chloroquine abrogated the T cell response to all antigens except for a nine-amino acid synthetic peptide representing a partial analogue of the group a determinant of HBsAg S(139-147). The significance of these results is discussed in the context of understanding the mechanism of mimicry elicited by the anti-Id.

scholarly journals Evaluation of Solid Lipid Nanoparticles as Carriers for Delivery of Hepatitis B Surface Antigen for Vaccination Using Subcutaneous Route

2010 ◽  
Vol 13 (4) ◽  
pp. 495 ◽  
Author(s):  
Dinesh Mishra ◽  
Himanshu Mishra ◽  
Pradyumna K. Mishra ◽  
Manoj Nahar ◽  
Vaibhav Dubey ◽  
...  
Keyword(s):  
Immune Response ◽  
Hepatitis B ◽  
Cellular Uptake ◽  
Surface Antigen ◽  
Solid Lipid Nanoparticles ◽  
Hepatitis B Surface Antigen ◽  
Lipid Nanoparticles ◽  
Subcutaneous Route

Purpose: Solid lipid nanoparticles (SLN) have emerged as carriers for therapeutic peptides, proteins, antigens and bioactive molecules. We have explored the potential of SLN as carrier for Hepatitis B surface antigen (HBsAg) by surface modifications to enhance their loading efficiency and the cellular uptake, using subcutaneous route. Methods: Four different formulations of SLN were prepared by solvent injection method and characterized for various physical properties: particle size, surface morphology, shape, zeta potential, polydispersity, X-ray diffraction analysis, release profile and entrapment efficiency. HBsAg loaded SLN were studied for their functional characteristics, in vitro cellular uptake and internalization studies by human dendritic cells, macrophages and fibroblasts, T cell proliferation and TH1/TH2 response. Humoral immune response elicited by subcutaneously administered HBsAg containing SLN formulations were studied in vivo in mice. Results: Compared to soluble HBsAg; SLN, particularly the mannosylated formulation, showed better cellular uptake, lesser cytotoxicity and induction of greater TH1 type of immune response. They also showed better immunological potential by producing sustained antibody titer. Conclusion: Mannosylated SLN appears to be promising as carrier for vaccine delivery against hepatitis B as ascertained by in vitro and in vivo studies, however further investigations on humans are required to establish their potential as vaccines against hepatitis B infection.

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