scholarly journals Effect of Plasmid DNA Vaccine Design and In Vivo Electroporation on the Resulting Vaccine-Specific Immune Responses in Rhesus Macaques

2007 ◽  
Vol 81 (10) ◽  
pp. 5257-5269 ◽  
Author(s):  
Amara Luckay ◽  
Maninder K. Sidhu ◽  
Rune Kjeken ◽  
Shakuntala Megati ◽  
Siew-Yen Chong ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Plasmid Dna ◽  
Vaccine Design ◽  
Fold Increase ◽  
Specific Cell ◽  
In Vivo Electroporation ◽  
High Molecular Weight Dna ◽  
Hiv 1

ABSTRACT Since human immunodeficiency virus (HIV)-specific cell-mediated immune (CMI) responses are critical in the early control and resolution of HIV infection and correlate with postchallenge outcomes in rhesus macaque challenge experiments, we sought to identify a plasmid DNA (pDNA) vaccine design capable of eliciting robust and balanced CMI responses to multiple HIV type 1 (HIV-1)-derived antigens for further development. Previously, a number of two-, three-, and four-vector pDNA vaccine designs were identified as capable of eliciting HIV-1 antigen-specific CMI responses in mice (M. A. Egan et al., Vaccine 24:4510-4523, 2006). We then sought to further characterize the relative immunogenicities of these two-, three-, and four-vector pDNA vaccine designs in nonhuman primates and to determine the extent to which in vivo electroporation (EP) could improve the resulting immune responses. The results indicated that a two-vector pDNA vaccine design elicited the most robust and balanced CMI response. In addition, vaccination in combination with in vivo EP led to a more rapid onset and enhanced vaccine-specific immune responses. In macaques immunized in combination with in vivo EP, we observed a 10- to 40-fold increase in HIV-specific enzyme-linked immunospot assay responses compared to those for macaques receiving a 5-fold higher dose of vaccine without in vivo EP. This increase in CMI responses translates to an apparent 50- to 200-fold increase in pDNA vaccine potency. Importantly, in vivo EP enhanced the immune response against the less immunogenic antigens, resulting in a more balanced immune response. In addition, in vivo EP resulted in an approximate 2.5-log10 increase in antibody responses. The results further indicated that in vivo EP was associated with a significant reduction in pDNA persistence and did not result in an increase in pDNA associated with high-molecular-weight DNA relative to macaques receiving the pDNA without EP. Collectively, these results have important implications for the design and development of an efficacious vaccine for the prevention of HIV-1 infection.

scholarly journals In Vivo Electroporation of Minicircle DNA as a Novel Method of Vaccine Delivery To Enhance HIV-1-Specific Immune Responses

2013 ◽  
Vol 88 (4) ◽  
pp. 1924-1934 ◽  
Author(s):  
Q. Wang ◽  
W. Jiang ◽  
Y. Chen ◽  
P. Liu ◽  
C. Sheng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Delivery ◽  
In Vivo Electroporation ◽  
Novel Method ◽  
Minicircle Dna ◽  
Hiv 1

scholarly journals Optimization of Human Immunodeficiency Virus Gag Expression by Newcastle Disease Virus Vectors for the Induction of Potent Immune Responses

2008 ◽  
Vol 83 (2) ◽  
pp. 584-597 ◽  
Author(s):  
Elena Carnero ◽  
Wenjing Li ◽  
Antonio V. Borderia ◽  
Bruno Moltedo ◽  
Thomas Moran ◽  
...  
Keyword(s):  
Immune Response ◽  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Insertion Site ◽  
Gag Protein ◽  
Immunodeficiency Virus

ABSTRACT One attractive strategy for the development of a human immunodeficiency virus (HIV) vaccine is the use of viral vectors with a proven safety profile and an absence of preexisting immunity in humans, such as Newcastle disease virus (NDV). Several NDV vaccine vectors have been generated, and their immunogenicities have been investigated with different animal models. However, a systematic study to evaluate the optimal insertion site of the foreign antigens into NDV that results in enhanced immune responses specific to the antigen has not yet been conducted. In this article, we describe the ability of NDV expressing HIV Gag to generate a Gag-specific immune response in mice. We also have determined the optimal insertion site into the NDV genome by generating recombinant NDV-HIVGag viruses in which HIV gag was located at different transcriptional positions throughout the NDV viral genome. All recombinant viruses were viable, grew to similar titers in embryonated chicken eggs, and expressed Gag in a stable manner. Our in vivo experiments revealed that higher HIV Gag protein expression positively correlates with an enhanced CD8+ T-cell-mediated immune response and protective immunity against challenge with vaccinia virus expressing HIV Gag. We also inserted a codon-optimized version of HIV gag in the described best location, between the P and M genes. Virus expressing the codon-optimized version of HIV gag induced a higher expression of the protein and an enhanced immune response against HIV Gag in mice. These results indicate that strategies directed toward increasing antigen expression by NDV result in enhanced immunogenicity and vaccine efficacy.

scholarly journals Impact of Influenza A Virus Shutoff Proteins on Host Immune Responses

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 629
Author(s):  
Megan M. Dunagan ◽  
Kala Hardy ◽  
Toru Takimoto
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Influenza A Virus ◽  
Influenza A ◽  
Human Populations ◽  
Lymphocyte Migration ◽  
Host Immune Responses ◽  
Mhc Molecules ◽  
The Impact

Influenza A virus (IAV) is a significant human pathogen that causes seasonal epidemics. Although various types of vaccines are available, IAVs still circulate among human populations, possibly due to their ability to circumvent host immune responses. IAV expresses two host shutoff proteins, PA-X and NS1, which antagonize the host innate immune response. By transcriptomic analysis, we previously showed that PA-X is a major contributor for general shutoff, while shutoff active NS1 specifically inhibits the expression of host cytokines, MHC molecules, and genes involved in innate immunity in cultured human cells. So far, the impact of these shutoff proteins in the acquired immune response in vivo has not been determined in detail. In this study, we analyzed the effects of PA-X and NS1 shutoff activities on immune response using recombinant influenza A/California/04/2009 viruses containing mutations affecting the expression of shutoff active PA-X and NS1 in a mouse model. Our data indicate that the virus without shutoff activities induced the strongest T and B cell responses. Both PA-X and NS1 reduced host immune responses, but shutoff active NS1 most effectively suppressed lymphocyte migration to the lungs, antibody production, and the generation of IAV specific CD4+ and CD8+ T cells. NS1 also prevented the generation of protective immunity against a heterologous virus challenge. These data indicate that shutoff active NS1 plays a major role in suppressing host immune responses against IAV infection.

scholarly journals Optimized Adenovirus-Antibody Complexes Stimulate Strong Cellular and Humoral Immune Responses against an Encoded Antigen in Naïve Mice and Those with Preexisting Immunity

2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
T Cell Responses ◽  
Transduction Efficiency ◽  
Virus Antibody ◽  
Cell Responses

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.

scholarly journals X4 Human Immunodeficiency Virus Type 1 gp120 Down-Modulates Expression and Immunogenicity of Codelivered Antigens

2009 ◽  
Vol 83 (21) ◽  
pp. 10941-10950 ◽  
Author(s):  
Avi-Hai Hovav ◽  
Michael Santosuosso ◽  
Maytal Bivas-Benita ◽  
Andre Plair ◽  
Alex Cheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Human Immunodeficiency Virus ◽  
Antigen Presentation ◽  
Antigen Expression ◽  
V3 Loop ◽  
Humoral Immune ◽  
Immunodeficiency Virus ◽  
Aids Vaccines ◽  
Hiv 1

ABSTRACT In order to increase the immune breadth of human immunodeficiency virus (HIV) vaccines, strategies such as immunization with several HIV antigens or centralized immunogens have been examined. HIV-1 gp120 protein is a major immunogen of HIV and has been routinely considered for inclusion in both present and future AIDS vaccines. However, recent studies proposed that gp120 interferes with the generation of immune response to codelivered antigens. Here, we investigate whether coimmunization with plasmid-encoded gp120 alters the immune response to other coadministered plasmid encoded antigens such as luciferase or ovalbumin in a mouse model. We found that the presence of gp120 leads to a significant reduction in the expression level of the codelivered antigen in vivo. Antigen presentation by antigen-presenting cells was also reduced and resulted in the induction of weak antigen-specific cellular and humoral immune responses. Importantly, gp120-mediated immune interference was observed after administration of the plasmids at the same or at distinct locations. To characterize the region in gp120 mediating these effects, we used plasmid constructs encoding gp120 that lacks the V1V2 loops (ΔV1V2) or the V3 loop (ΔV3). After immunization, the ΔV1V2, but not the ΔV3 construct, was able to reduce antigen expression, antigen presentation, and subsequently the immunogenicity of the codelivered antigen. The V3 loop dependence of this phenomenon seems to be limited to V3 loops known to interact with the CXCR4 molecule but not with CCR5. Our study presents a novel mechanism by which HIV-1 gp120 interferes with the immune response against coadministered antigen in a polyvalent vaccine preparation.

scholarly journals GENETIC CONTROL OF IMMUNE RESPONSES IN VITRO

1974 ◽  
Vol 140 (3) ◽  
pp. 648-659 ◽  
Author(s):  
Judith A. Kapp ◽  
Carl W. Pierce ◽  
Stuart Schlossman ◽  
Baruj Benacerraf
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune Responses ◽  
Cell Function ◽  
Suppressor Cells ◽  
Specific Response ◽  
Spleen Cells ◽  
X Irradiation

In recent studies we have found that GAT not only fails to elicit a GAT-specific response in nonresponder mice but also specifically decreases the ability of nonresponder mice to develop a GAT-specific PFC response to a subsequent challenge with GAT bound to the immunogenic carrier, MBSA. Studies presented in this paper demonstrate that B cells from nonresponder, DBA/1 mice rendered unresponsive by GAT in vivo can respond in vitro to GAT-MBSA if exogenous, carrier-primed T cells are added to the cultures. The unresponsiveness was shown to be the result of impaired carrier-specific helper T-cell function in the spleen cells of GAT-primed mice. Spleen cells from GAT-primed mice specifically suppressed the GAT-specific PFC response of spleen cells from normal DBA/1 mice incubated with GAT-MBSA. This suppression was prevented by pretreatment of GAT-primed spleen cells with anti-θ serum plus C or X irradiation. Identification of the suppressor cells as T cells was confirmed by the demonstration that suppressor cells were confined to the fraction of the column-purified lymphocytes which contained θ-positive cells and a few non-Ig-bearing cells. The significance of these data to our understanding of Ir-gene regulation of the immune response is discussed.

Unravelling the net? cytokines and diseases

2000 ◽  
Vol 113 (20) ◽  
pp. 3549-3550
Author(s):  
M.J. Townsend ◽  
A.N. McKenzie
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
T Helper ◽  
Cytokine Network ◽  
In Vivo Models ◽  
Cytokines And Chemokines ◽  
Cytokine Networks ◽  
Th2 Development ◽  
Helper Type

The Cytokine Network edited by Fran Balkwill Frontiers in Molecular Biology Series (seried editors B. D. Hames and D. M. Glover) Oxford University Press (2000) pp. 199. ISBN 019–963-702-4. 29.95 Cytokines are small- to medium-sized proteins and glycoproteins that mediate highly potent biological effects on many cell types. They have critical roles in haematopoiesis, inflammatory responses and the development and maintenance of immune responses. Importantly, cytokines act in networks or cascades. Typical properties of cytokines in these networks are pleiotropy, redundancy, synergistic activity and antagonistic effects upon each other. Knowledge of how these networks are comprised and operate is important in understanding how cytokines mediate their diverse effects on biological systems. In The Cytokine Network, Fran Balkwill brings together some distinguished investigators to produce a survey, in eight independently written and concise chapters, of the complex cytokine and chemokine (chemotactic cytokine) networks present in mouse and man. The ever-increasing complexity of cytokine networks is introduced in the initial chapter with a summary of the bioinformatics approach for the high throughput discovery of novel cytokines and chemokines. The burgeoning number of newly identified chemokines, chemokine receptors and TNF family members reminds us that our understanding of the cytokine network is extremely dynamic and that our interpretation of some pathways will change with the characterisation of new factors. The following chapters address the interactions of the cytokines, both with reference to their signalling pathways (well summarised in chapter 2) and their biological roles. The point is made that cytokines should be studied as a network rather than individually and that in vivo models, including the generation of transgenic and gene knock-out mice, are powerful tools for doing so. Rheumatoid arthritis is presented as a well-studied example of how inappropriate regulation of pro- and anti-inflammatory cytokines mediates autoimmune disease, and examples of immunoregulatory cytokines that have both overlapping and independent regulatory effects on inflammation are demonstrated within this context. The important Th1/Th2 paradigm receives a dedicated chapter. T helper type 1 and T helper type 2 cells produce distinct and restricted patterns of cytokines that cross regulate each other and thus mediate different types of immune response. The development of these subsets of T helper cells from a common precursor, as part of a developing immune response, has important effects on the cytokine network. The mechanisms of Th1/Th2 development together with modulating factors and associated intracellular signalling are well described. The chapter summarises well the role of Th1/Th2 development in human diseases with reference to transplantation immunology, neonatal development, autoimmune diseases, and atopic diseases. A very interesting review of the relationships between cytokines and viruses is given. Cytokines are critically involved in mediating antiviral immune responses. However, homologues of cytokines, chemokines and their receptors, after being ‘hijacked’ from the host genome and undergoing evolution along with the viral genes, are utilised by viruses themselves to promote their replication and to suppress immune responses against them. The chapter describes several noteworthy examples of these virally encoded cytokines and receptors together with their roles in vivo. This is a well-written book that provides a good introduction to understanding how cytokines and chemokines interact as a network in the immune system. The volume links together diverse subjects that include cytokine signalling, genomic polymorphism, disease processes and immunotherapies. The book does not aim to describe comprehensively the biology of all the currently known cytokines and chemokines and therefore alternative texts should be considered for this. (ABSTRACT TRUNCATED)

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