scholarly journals Protective Immunity Elicited by a Divalent DNA Vaccine Encoding Both the L7/L12 and Omp16 Genes of Brucella abortus in BALB/c Mice

2006 ◽  
Vol 74 (5) ◽  
pp. 2734-2741 ◽  
Author(s):  
Deyan Luo ◽  
Bing Ni ◽  
Peng Li ◽  
Wei Shi ◽  
Songle Zhang ◽  
...  
Keyword(s):  
Immune Response ◽  
Dna Vaccine ◽  
Brucella Abortus ◽  
Protective Efficacy ◽  
Virulent Strain ◽  
T Helper 1 ◽  
Genetic Vaccine ◽  
Cellular Immune

ABSTRACT This study was designed to evaluate the immunogenicity and the protective efficacy of a divalent fusion DNA vaccine encoding both the Brucella abortus L7/L12 protein (ribosomal protein) and Omp16 protein (outer membrane lipoprotein), designated pcDNA3.1-L7/L12-Omp16. Intramuscular injection of this divalent DNA vaccine into BALB/c mice elicited markedly both humoral and cellular immune responses. The specific antibodies exhibited a dominance of immunoglobulin G2a (IgG2a) over IgG1. In addition, the dual-gene DNA vaccine elicited a strong T-cell proliferative response and induced a large amount of gamma interferon-producing T cells upon restimulation in vitro with recombinant fusion protein L7/L12-Omp16, suggesting the induction of a typical T-helper-1-dominated immune response in vivo. This divalent DNA vaccine could also induce a significant level of protection against challenge with the virulent strain B. abortus 544 in BALB/c mice. Furthermore, the protection level induced by the divalent DNA vaccine was significantly higher than that induced by the univalent DNA vaccines pcDNA3.1-L7/L12 or pcDNA3.1-Omp16. Taken together, the results of this study verify for the first time that the Omp16 gene can be a candidate target for a DNA vaccine against brucellosis. Additionally, a divalent genetic vaccine based on the L7/L12 and Omp16 genes can elicit a stronger cellular immune response and better immunoprotection than the relevant univalent vaccines can.

scholarly journals A DNA Vaccine Encoding Cu,Zn Superoxide Dismutase of Brucella abortus Induces Protective Immunity in BALB/c Mice

2003 ◽  
Vol 71 (9) ◽  
pp. 4857-4861 ◽  
Author(s):  
Angel A. Oñate ◽  
Sandra Céspedes ◽  
Alex Cabrera ◽  
Rodolfo Rivers ◽  
Andrés González ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Dna Vaccine ◽  
Brucella Abortus ◽  
Protective Efficacy ◽  
Virulent Strain ◽  
Interleukin 10 ◽  
T Helper 1 ◽  
Cellular Immune Responses ◽  
The One ◽  
Cellular Immune

ABSTRACT This study was conducted to evaluate the immunogenicity and protective efficacy of a DNA vaccine encoding Brucella abortus Cu,Zn superoxide dismutase (SOD). Intramuscular injection of plasmid DNA carrying the SOD gene (pcDNA-SOD) into BALB/c mice elicited both humoral and cellular immune responses. Animals injected with pcDNA-SOD developed SOD-specific antibodies which exhibited a dominance of immunoglobulin G2a (IgG2a) over IgG1. In addition, the DNA vaccine elicited a T-cell-proliferative response and also induced the production of gamma interferon, but not interleukin-10 (IL-10) or IL-4, upon restimulation with either recombinant SOD or crude Brucella protein, suggesting the induction of a typical T-helper-1-dominated immune response in mice. The pcDNA-SOD (but not the control vector) induced a strong, significant level of protection in BALB/c mice against challenge with B. abortus virulent strain 2308; the level of protection was similar to the one induced by B. abortus vaccine strain RB51. Altogether, these data suggest that pcDNA-SOD is a good candidate for use in future studies of vaccination against brucellosis.

scholarly journals A targeted complement-dependent strategy to improve the outcome of mAb therapy, and characterization in a murine model of metastatic cancer

Blood ◽  
2012 ◽  
Vol 119 (25) ◽  
pp. 6043-6051 ◽  
Author(s):  
Michelle Elvington ◽  
Yuxiang Huang ◽  
B. Paul Morgan ◽  
Fei Qiao ◽  
Nico van Rooijen ◽  
...  
Keyword(s):  
Immune Response ◽  
Tumor Cell ◽  
Complement Activation ◽  
Metastatic Cancer ◽  
Protein Targets ◽  
Complement Inhibitors ◽  
Activation Products ◽  
Cellular Immune

Abstract Complement inhibitors expressed on tumor cells provide an evasion mechanism against mAb therapy and may modulate the development of an acquired antitumor immune response. Here we investigate a strategy to amplify mAb-targeted complement activation on a tumor cell, independent of a requirement to target and block complement inhibitor expression or function, which is difficult to achieve in vivo. We constructed a murine fusion protein, CR2Fc, and demonstrated that the protein targets to C3 activation products deposited on a tumor cell by a specific mAb, and amplifies mAb-dependent complement activation and tumor cell lysis in vitro. In syngeneic models of metastatic lymphoma (EL4) and melanoma (B16), CR2Fc significantly enhanced the outcome of mAb therapy. Subsequent studies using the EL4 model with various genetically modified mice and macrophage-depleted mice revealed that CR2Fc enhanced the therapeutic effect of mAb therapy via both macrophage-dependent FcγR-mediated antibody-dependent cellular cytotoxicity, and by direct complement-mediated lysis. Complement activation products can also modulate adaptive immunity, but we found no evidence that either mAb or CR2Fc treatment had any effect on an antitumor humoral or cellular immune response. CR2Fc represents a potential adjuvant treatment to increase the effectiveness of mAb therapy of cancer.

scholarly journals Characterization of Specific Immune Responses of Mice Inoculated with Recombinant Vaccinia Virus Expressing an 18-Kilodalton Outer Membrane Protein of Brucella abortus

2000 ◽  
Vol 7 (1) ◽  
pp. 114-118 ◽  
Author(s):  
Ramesh Vemulapalli ◽  
Silvio Cravero ◽  
Christine L. Calvert ◽  
Thomas E. Toth ◽  
Nammalwar Sriranganathan ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Vaccinia Virus ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Brucella Abortus ◽  
Virulent Strain ◽  
Shuttle Vector ◽  
Protein Fusion

ABSTRACT Using the shuttle vector pMCO2 and the vaccinia virus wild-type WR strain, we constructed a recombinant virus expressing an 18-kDa outer membrane protein of Brucella abortus. BALB/c mice inoculated with this virus produced 18-kDa protein-specific antibodies, mostly of immunoglobulin G2a isotype, and in vitro stimulation of splenocytes from these mice with purified maltose binding protein–18-kDa protein fusion resulted in lymphocyte proliferation and gamma interferon production. However, these mice were not protected against a challenge with the virulent strain B. abortus2308. Disruption of the 18-kDa protein's gene in vaccine strainB. abortus RB51 did not affect either the strain's protective capabilities or its in vivo attenuation characteristics. These observations suggest that the 18-kDa protein plays no role in protective immunity.

scholarly journals Eucommia ulmoides Leaf Polysaccharide in Conjugation with Ovalbumin Act as Delivery System Can Improve Immune Response

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1384
Author(s):  
Haibo Feng ◽  
Jie Yang ◽  
Hui Zhi ◽  
Xin Hu ◽  
Yan Yang ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Delivery System ◽  
Physicochemical Characteristics ◽  
Cellular Immune Responses ◽  
Ethylcarbodiimide Hydrochloride ◽  
Ifn Γ ◽  
Cellular Immune

In this investigation, to maximize the desired immunoenhancement effects of PsEUL and stimulate an efficient humoral and cellular immune response against an antigen, PsEUL and the model antigen ovalbumin (OVA) were coupled using the N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) reaction to yield a novel delivery system (PsEUL-OVA). The physicochemical characteristics and immune regulation effects of this new system were investigated. We found the yield of this EDC method to be 46.25%. In vitro, PsEUL-OVA (200 μg mL−1) could enhance macrophage proliferation and increase their phagocytic efficiency. In vivo, PsEUL-OVA could significantly increase the levels of OVA-specific antibody (IgG, IgG1, IgG2a, and IgG2b) titers and cytokine (IL-2, IL-4, IL-6, IFN-γ) levels. Additionally, it could activate T lymphocytes and facilitate the maturation of dendritic cells (DCs). These findings collectively suggested that PsEUL-OVA induced humoral and cellular immune responses by promoting the phagocytic activity of macrophages and DCs. Taken together, these results revealed that PsEUL-OVA had the potential to improve immune responses and provide a promising theoretical basis for the design of a novel delivery system.

scholarly journals Stimulation of Dendritic Cells via CD40 Enhances Immune Responses to Mycobacterium tuberculosisInfection

2001 ◽  
Vol 69 (4) ◽  
pp. 2456-2461 ◽  
Author(s):  
Caroline Demangel ◽  
Umaimainthan Palendira ◽  
Carl G. Feng ◽  
Andrew W. Heath ◽  
Andrew G. D. Bean ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Interleukin 12 ◽  
Ifn Γ ◽  
Cellular Immune ◽  
Stimulation Of

ABSTRACT The resolution of pulmonary tuberculosis (TB) critically depends on the development of the Th1 type of immune responses, as exemplified by the exacerbation of TB in IL-12-deficient mice. Therefore, vaccination strategies optimizing IL-12 production by antigen-presenting cells (APC) in response to mycobacteria may have enhanced protective efficacy. Since dendritic cells (DC) are the critical APC for activation of CD4+ and CD8+ T cells, we examined whether stimulation of Mycobacterium bovis bacillus Calmette Guérin (BCG)-infected DC via CD40 increased their ability to generate Th1-oriented cellular immune responses. Incubation of DC with an agonistic anti-CD40 antibody activated CD40 signaling in DC, as shown by increased expression of major histocompatibility complex class II and costimulatory molecules, mRNA production for proinflammatory cytokines and interleukin 12 (IL-12) p40. This activation pattern was maintained when DC were stimulated with anti-CD40 antibody and infected with BCG. Importantly, CD40-stimulated BCG-infected DC displayed increased capacity to release bioactive IL-12 and to activate gamma interferon (IFN-γ) producing T cells in vitro. Moreover, when C57BL/6 mice were immunized with these DC and challenged with aerosol Mycobacterium tuberculosis, increased levels of mRNA for IL-12 p40, IL-18, and IFN-γ were present in the draining mediastinal lymph nodes. However, the mycobacterial burden in the lungs was not reduced compared to that in mice immunized with BCG-infected non-CD40-stimulated DC. Therefore, although the manipulation of DC via CD40 is effective for enhancing immune responses to mycobacteria in vivo, additional strategies are required to increase protection against virulent M. tuberculosis infection.

scholarly journals Immune effects against influenza A virus and a novel DNA vaccine with co-expression of haemagglutinin- and neuraminidase-encoding genes

2009 ◽  
Vol 58 (7) ◽  
pp. 845-854 ◽  
Author(s):  
Weidong Zhang ◽  
Wanyi Li ◽  
Yan Li ◽  
Hong Li ◽  
Baoning Wang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Dna Vaccine ◽  
Influenza A ◽  
Protective Efficacy ◽  
Survival Rates ◽  
Serum Antibody ◽  
Lethal Challenge ◽  
Vector Systems

The high variability of influenza virus causes difficulties in the control and prevention of influenza, thus seeking a promising approach for dealing with these problems is a hot topic. Haemagglutinin (HA) and neuraminidase (NA) are major surface antigens of the influenza virus, and provide effective protection against lethal challenges with this virus. We constructed a DNA vaccine (pHA-IRES2-NA) that co-expressed both HA and NA, and compared its protective efficacy and immunogenic ability with that of singly expressed HA or NA, or a mixture of the two singly expressed proteins. Our findings showed that both HA and NA proteins expressed by pHA-IRES2-NA could be detected in vivo and in vitro. The protection of DNA vaccines was evaluated by serum antibody titres, residual lung virus titres and survival rates of the mice. In the murine model, immunization of pHA-IRES2-NA generated significant anti-HA and anti-NA antibody, increased the percentage of CD8+ cells and gamma interferon-producing CD8+ cells and the ratio of Th1/Th2 (T helper) cells, which was comparable to the effects of immunization with HA or NA DNA alone or with a mixture of HA and NA DNA. All the mice inoculated by pHA-IRES2-NA resisted the lethal challenge by homologous influenza virus and survived with low lung virus titre. In addition, previous studies reported that co-expression allowed higher-frequency transduction compared to co-transduction of separated vector systems encoding different genes. The novel HA and NA co-expression DNA vaccine is a successful alternative to using a mixture of purified HA and NA proteins or HA and NA DNA.

scholarly journals Positive and Negative Regulation of Cellular Immune Responses in Physiologic Conditions and Diseases

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
S. Viganò ◽  
M. Perreau ◽  
G. Pantaleo ◽  
A. Harari
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Immune Responses ◽  
Viral Infections ◽  
Therapeutic Interventions ◽  
Cellular Immune

The immune system has evolved to allow robust responses against pathogens while avoiding autoimmunity. This is notably enabled by stimulatory and inhibitory signals which contribute to the regulation of immune responses. In the presence of a pathogen, a specific and effective immune response must be induced and this leads to antigen-specific T-cell proliferation, cytokines production, and induction of T-cell differentiation toward an effector phenotype. After clearance or control of the pathogen, the effector immune response must be terminated in order to avoid tissue damage and chronic inflammation and this process involves coinhibitory molecules. When the immune system fails to eliminate or control the pathogen, continuous stimulation of T cells prevents the full contraction and leads to the functional exhaustion of effector T cells. Several evidences bothin vitroandin vivosuggest that this anergic state can be reverted by blocking the interactions between coinhibitory molecules and their ligands. The potential to revert exhausted or inactivated T-cell responses following selective blocking of their function made these markers interesting targets for therapeutic interventions in patients with persistent viral infections or cancer.

Sign in / Sign up

Export Citation Format

Share Document