scholarly journals Lower Levels of Gamma Interferon Expressed by a Pseudotyped Single-Cycle Simian Immunodeficiency Virus Enhance Immunogenicity in Rats

2008 ◽  
Vol 83 (4) ◽  
pp. 1592-1601 ◽  
Author(s):  
Yue Peng ◽  
Fan-ching Lin ◽  
Paulo H. Verardi ◽  
Leslie A. Jones ◽  
Tilahun D. Yilma
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Rat Model ◽  
Gamma Interferon ◽  
Fine Tuning ◽  
Vaccine Strategy ◽  
Single Cycle ◽  
Immunodeficiency Virus ◽  
Ifn Γ

ABSTRACT A vaccine for human immunodeficiency virus (HIV) infection is desperately needed to control the AIDS pandemic. To address this problem, we constructed single-cycle simian immunodeficiency viruses (SIVs) pseudotyped with the glycoprotein of vesicular stomatitis virus and expressing different levels of gamma interferon (IFN-γ) as a potential vaccine strategy. We previously showed that IFN-γ expression by pseudotyped SIVs does not alter viral single-cycle infectivity. T cells primed with dendritic cells transduced by pseudotyped SIVs expressing high levels of IFN-γ had stronger T-cell responses than those primed with dendritic cells transduced by constructs lacking IFN-γ. In the present study, we tested the immunogenicities of these pseudotyped SIVs in a rat model. The construct expressing low levels of rat IFN-γ (dSIVLRγ) induced higher levels of cell-mediated and humoral immune responses than the construct lacking IFN-γ (dSIVR). Rats vaccinated with dSIVLRγ also had lower viral loads than those vaccinated with dSIVR when inoculated with a recombinant vaccinia virus expressing SIV Gag-Pol as a surrogate challenge. The construct expressing high levels of IFN-γ (dSIVHRγ) did not further enhance immunity and was less protective than dSIVLRγ. In conclusion, the data indicated that IFN-γ functioned as an adjuvant to augment antigen-specific immune responses in a dose- and cell type-related manner in vivo. Thus, fine-tuning of the cytokine expression appears to be essential in designing vaccine vectors expressing adjuvant genes such as the gene for IFN-γ. Furthermore, we provide evidence of the utility of the rat model to evaluate the immunogenicities of single-cycle HIV/SIV recombinant vaccines before initiating studies with nonhuman primate models.

scholarly journals Human Immunodeficiency Virus (HIV)-Specific Gamma Interferon Secretion Directed against All Expressed HIV Genes: Relationship to Rate of CD4 Decline

2005 ◽  
Vol 79 (8) ◽  
pp. 4908-4917 ◽  
Author(s):  
Yoav Peretz ◽  
Galit Alter ◽  
Marie-Pierre Boisvert ◽  
George Hatzakis ◽  
Christos M. Tsoukas ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Immune Responses ◽  
Disease Progression ◽  
Mononuclear Cells ◽  
Gamma Interferon ◽  
Peripheral Blood Mononuclear ◽  
Slow Progressors ◽  
Immunodeficiency Virus ◽  
Ifn Γ

ABSTRACT Immune responses to human immunodeficiency virus (HIV) are detected at all stages of infection and are believed to be responsible for controlling viremia. This study seeks to determine whether gamma interferon (IFN-γ)-secreting HIV-specific T-cell responses influence disease progression as defined by the rate of CD4 decline. The study population consisted of 31 subjects naïve to antiretroviral therapy. All were monitored clinically for a median of 24 months after the time they were tested for HIV-specific responses. The rate of CD4+-T-cell loss was calculated for all participants from monthly CD4 counts. Within this population, 17 subjects were classified as typical progressors, 6 subjects were classified as fast progressors, and 8 subjects were classified as slow progressors. Peripheral blood mononuclear cells were screened for HIV-specific IFN-γ responses to all expressed HIV genes. Among the detected immune responses, 48% of the recognized peptides were encoded by Gag and 19% were encoded by Nef gene products. Neither the breadth nor the magnitude of HIV-specific responses correlated with the viral load or rate of CD4 decline. The breadth and magnitude of HIV-specific responses did not differ significantly among typical, fast, and slow progressors. These results support the conclusion that although diverse HIV-specific IFN-γ-secreting responses are mounted during the asymptomatic phase, these responses do not seem to modulate disease progression rates.

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 Comparison of Immunity Generated by Nucleic Acid-, MF59-, and ISCOM-Formulated Human Immunodeficiency Virus Type 1 Vaccines in Rhesus Macaques: Evidence for Viral Clearance

1999 ◽  
Vol 73 (4) ◽  
pp. 3292-3300 ◽  
Author(s):  
Ernst J. Verschoor ◽  
Petra Mooij ◽  
Herman Oostermeijer ◽  
Mike van der Kolk ◽  
Peter ten Haaft ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Human Immunodeficiency Virus Type ◽  
T Helper ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Hiv 1

ABSTRACT The kinetics of T-helper immune responses generated in 16 mature outbred rhesus monkeys (Macaca mulatta) within a 10-month period by three different human immunodeficiency virus type 1 (HIV-1) vaccine strategies were compared. Immune responses to monomeric recombinant gp120SF2 (rgp120) when the protein was expressed in vivo by DNA immunization or when it was delivered as a subunit protein vaccine formulated either with the MF59 adjuvant or by incorporation into immune-stimulating complexes (ISCOMs) were compared. Virus-neutralizing antibodies (NA) against HIV-1SF2 reached similar titers in the two rgp120SF2 protein-immunized groups, but the responses showed different kinetics, while NA were delayed and their levels were low in the DNA-immunized animals. Antigen-specific gamma interferon (IFN-γ) T-helper (type 1-like) responses were detected in the DNA-immunized group, but only after the fourth immunization, and the rgp120/MF59 group generated both IFN-γ and interleukin-4 (IL-4) (type 2-like) responses that appeared after the third immunization. In contrast, rgp120/ISCOM-immunized animals rapidly developed marked IL-2, IFN-γ (type 1-like), and IL-4 responses that peaked after the second immunization. To determine which type of immune responses correlated with protection from infection, all animals were challenged intravenously with 50 50% infective doses of a rhesus cell-propagated, in vivo-titrated stock of a chimeric simian immunodeficiency virus-HIVSF13 construct. Protection was observed in the two groups receiving the rgp120 subunit vaccines. Half of the animals in the ISCOM group were completely protected from infection. In other subunit vaccinees there was evidence by multiple assays that virus detected at 2 weeks postchallenge was effectively cleared. Early induction of potent type 1- as well as type 2-like T-helper responses induced the most-effective immunity.

scholarly journals Gamma Interferon Blocks Gammaherpesvirus Reactivation from Latency

2006 ◽  
Vol 80 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Ashley L. Steed ◽  
Erik S. Barton ◽  
Scott A. Tibbetts ◽  
Daniel L. Popkin ◽  
Mary L. Lutzke ◽  
...  
Keyword(s):  
Immune Surveillance ◽  
Viral Gene Expression ◽  
Gamma Interferon ◽  
Viral Gene ◽  
Herpesvirus Infection ◽  
Murine Gammaherpesvirus ◽  
Ifn Γ ◽  
Gammaherpesvirus 68 ◽  
Novel Strategy

ABSTRACT Establishment of latent infection and reactivation from latency are critical aspects of herpesvirus infection and pathogenesis. Interfering with either of these steps in the herpesvirus life cycle may offer a novel strategy for controlling herpesvirus infection and associated disease pathogenesis. Prior studies show that mice deficient in gamma interferon (IFN-γ) or the IFN-γ receptor have elevated numbers of cells reactivating from murine gammaherpesvirus 68 (γHV68) latency, produce infectious virus after the establishment of latency, and develop large-vessel vasculitis. Here, we demonstrate that IFN-γ is a powerful inhibitor of reactivation of γHV68 from latency in tissue culture. In vivo, IFN-γ controls viral gene expression during latency. Importantly, depletion of IFN-γ in latently infected mice results in an increased frequency of cells reactivating virus. This demonstrates that IFN-γ is important for immune surveillance that limits reactivation of γHV68 from latency.

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 Tolerogenic Splenic IDO+Dendritic Cells from the Mice Treated with Induced-Treg Cells Suppress Collagen-Induced Arthritis

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Jie Yang ◽  
Yiming Yang ◽  
Huahua Fan ◽  
Hejian Zou
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Foxp3 Expression ◽  
Treated Group ◽  
Treg Cells ◽  
Therapeutic Effects ◽  
Dependent Manner ◽  
Collagen Induced Arthritis

TGF-β-induced regulatory T cells (iTregs) retain Foxp3 expression and immune-suppressive activity in collagen-induced arthritis (CIA). However, the mechanisms whereby transferred iTregs suppress immune responses, particularly the interplay between iTregs and dendritic cells (DCs)in vivo, remain incompletely understood. In this study, we found that after treatment with iTregs, splenic CD11c+DCs, termed “DCiTreg,” expressed tolerogenic phenotypes, secreted high levels of IL-10, TGF-β, and IDO, and showed potent immunosuppressive activityin vitro. After reinfusion with DCiTreg, marked antiarthritic activity improved clinical scores and histological end-points were observed. The serological levels of inflammatory cytokines and anti-CII antibodies were low and TGF-βproduction was high in the DCiTreg-treated group. DCiTregalso induced new iTregsin vivo. Moreover, the inhibitory activity of DCiTregon CIA was lost following pretreatment with the inhibitor of indoleamine 2,3-dioxygenase (IDO). Collectively, these findings suggest that transferred iTregs could induce tolerogenic characteristics in splenic DCs and these cells could effectively dampen CIA in an IDO-dependent manner. Thus, the potential therapeutic effects of iTregs in CIA are likely maintained through the generation of tolerogenic DCsin vivo.

scholarly journals Resistance to Acute Babesiosis Is Associated with Interleukin-12- and Gamma Interferon-Mediated Responses and Requires Macrophages and Natural Killer Cells

2003 ◽  
Vol 71 (4) ◽  
pp. 2002-2008 ◽  
Author(s):  
Irma Aguilar-Delfin ◽  
Peter J. Wettstein ◽  
David H. Persing
Keyword(s):  
Nk Cells ◽  
Gamma Interferon ◽  
Interleukin 12 ◽  
No Production ◽  
Cytokine Responses ◽  
Early Production ◽  
Ifn Γ ◽  
Crucial Part

ABSTRACT We examined the role of the cytokines gamma interferon (IFN-γ) and interleukin-12 (IL-12) in the model of acute babesiosis with the WA1 Babesia. Mice genetically deficient in IFN-γ-mediated responses (IFNGR2KO mice) and IL-12-mediated responses (Stat4KO mice) were infected with the WA1 Babesia, and observations were made on the course of infection and cytokine responses. Levels of IFN-γ and IL-12 in serum increased 24 h after parasite inoculation. The augmented susceptibility observed in IFNGR2KO and Stat-4KO mice suggests that the early IL-12- and IFN-γ-mediated responses are involved in protection against acute babesiosis. Resistance appears to correlate with an increase in nitric oxide (NO) production. In order to assess the contribution of different cell subsets to resistance against the parasite, we also studied mice lacking B cells, CD4+ T cells, NK cells, and macrophages. Mice genetically deficient in B lymphocytes or CD4+ T lymphocytes were able to mount protective responses comparable to those of immunosufficient mice. In contrast, in vivo depletion of macrophages or NK cells resulted in elevated susceptibility to the infection. Our observations suggest that a crucial part of the response that protects from the pathogenic Babesia WA1 is mediated by macrophages and NK cells, probably through early production of IL-12 and IFN-γ, and induction of macrophage-derived effector molecules like NO.

scholarly journals A genetically engineered adenovirus vector targeted to CD40 mediates transduction of canine dendritic cells and promotes antigen-specific immune responses in vivo

Vaccine ◽  
2009 ◽  
Vol 27 (50) ◽  
pp. 7116-7124 ◽  
Author(s):  
Erin E. Thacker ◽  
Masaharu Nakayama ◽  
Bruce F. Smith ◽  
R. Curtis Bird ◽  
Zhanat Muminova ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Adenovirus Vector ◽  
Genetically Engineered

scholarly journals Gamma Interferon Produced by Antigen-Specific CD4+ T Cells Regulates the Mucosal Immune Responses to Citrobacter rodentium Infection

2010 ◽  
Vol 78 (6) ◽  
pp. 2653-2666 ◽  
Author(s):  
Hideyuki Shiomi ◽  
Atsuhiro Masuda ◽  
Shin Nishiumi ◽  
Masayuki Nishida ◽  
Tetsuya Takagawa ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Gamma Interferon ◽  
Immune Defense ◽  
Interleukin 4 ◽  
Mucosal Inflammation ◽  
Citrobacter Rodentium ◽  
Macrophage Phagocytosis ◽  
Ifn Γ ◽  
Deficient Mice

ABSTRACT Citrobacter rodentium, a murine model pathogen for enteropathogenic Escherichia coli, colonizes the surface of intestinal epithelial cells and causes mucosal inflammation. This bacterium is an ideal model for investigating pathogen-host immune interactions in the gut. It is well known that gene transcripts for Th1 cytokines are highly induced in colonic tissue from mice infected with C. rodentium. However, it remains to be seen whether the Th1 or Th2 cytokines produced by antigen-specific CD4+ T cells provide effective regulation of the host immune defense against C. rodentium infection. To investigate the antigen-specific immune responses, C. rodentium expressing ovalbumin (OVA-C. rodentium), a model antigen, was generated and used to define antigen-specific responses under gamma interferon (IFN-γ)-deficient or interleukin-4 (IL-4)-deficient conditions in vivo. The activation of antigen-specific CD4+ T cells and macrophage phagocytosis were evaluated in the presence of IFN-γ or IL-4 in vitro. IFN-γ-deficient mice exhibited a loss of body weight and a higher bacterial concentration in feces during OVA-C. rodentium infection than C57BL/6 (wild type) or IL-4-deficient mice. This occurred through the decreased efficiency of macrophage phagocytosis and the activation of antigen-specific CD4+ T cells. Furthermore, a deficiency in antigen-specific CD4+ T-cell-expressed IFN-γ led to a higher susceptibility to mucosal and gut-derived systemic OVA-C. rodentium infection. These results show that the IFN-γ produced by antigen-specific CD4+ T cells plays an important role in the defense against C. rodentium.

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