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Burlingame, CA, United States

Ireland R.,U.S. National Institutes of Health | Olivares-Zavaleta N.,U.S. National Institutes of Health | Warawa J.M.,U.S. National Institutes of Health | Gherardini F.C.,U.S. National Institutes of Health | And 5 more authors.
PLoS Pathogens

Protection against virulent pathogens that cause acute, fatal disease is often hampered by development of microbial resistance to traditional chemotherapeutics. Further, most successful pathogens possess an array of immune evasion strategies to avoid detection and elimination by the host. Development of novel, immunomodulatory prophylaxes that target the host immune system, rather than the invading microbe, could serve as effective alternatives to traditional chemotherapies. Here we describe the development and mechanism of a novel pan-anti-bacterial prophylaxis. Using cationic liposome non-coding DNA complexes (CLDC) mixed with crude F. tularensis membrane protein fractions (MPF), we demonstrate control of virulent F. tularensis infection in vitro and in vivo. CLDC+MPF inhibited bacterial replication in primary human and murine macrophages in vitro. Control of infection in macrophages was mediated by both reactive nitrogen species (RNS) and reactive oxygen species (ROS) in mouse cells, and ROS in human cells. Importantly, mice treated with CLDC+MPF 3 days prior to challenge survived lethal intranasal infection with virulent F. tularensis. Similarly to in vitro observations, in vivo protection was dependent on the presence of RNS and ROS. Lastly, CLDC+MPF was also effective at controlling infections with Yersinia pestis, Burkholderia pseudomallei and Brucella abortus. Thus, CLDC+MPF represents a novel prophylaxis to protect against multiple, highly virulent pathogens. Source

Bernstein D.I.,University of Cincinnati | Earwood J.D.,University of Cincinnati | Bravo F.J.,University of Cincinnati | Cohen G.H.,University of Pennsylvania | And 4 more authors.

Genital herpes simplex virus (HSV) infections are common but results from vaccine trials with HSV-2 glycoprotein D (gD) have been disappointing. We therefore compared a similar HSV gD2 vaccine, to a further truncated gD2 vaccine, to a vaccine with gD2 plus gB2 and gH2/gL2 and to a vaccine with only gB2 and gH2/gL2 in a guinea pig model of genital herpes. All vaccines were administered with cationic liposome-DNA complexes (CLDC) as an adjuvant. All vaccines significantly decreased the severity of acute genital disease and vaginal virus replication compared to the placebo group. The majority of animals in all groups developed at least one episode of recurrent disease but the frequency of recurrent disease was significantly reduced by each vaccine compared to placebo. No vaccine was significantly more protective than gD2 alone for any of the parameters described above. No vaccine decreased recurrent virus shedding. When protection against acute infection of dorsal root ganglia and the spinal cord was evaluated all vaccines decreased the per cent of animal with detectable virus and the quantity of virus but again no vaccine was significantly more protective than another. Improvements in HSV-2 vaccines may require inclusion of more T cell targets, more potent adjuvants or live virus vaccines. © 2011 Elsevier Ltd. Source

Bernstein D.I.,University of Cincinnati | Farley N.,University of Cincinnati | Bravo F.J.,University of Cincinnati | Earwood J.,University of Cincinnati | And 3 more authors.

Herpes simplex virus (HSV) infections are common but there is no vaccine available. We evaluated cationic liposome-DNA complexes (CLDC) as an adjuvant for an HSV gD2 vaccine and compared it to an MPL/Alum adjuvant in a guinea pig model of genital herpes. The addition of CLDC to the gD2 vaccine significantly decreased acute and recurrent disease and most importantly the number of days with recurrent virus shedding compared to gD2 alone. Reductions in these outcomes were also detected when gD2 + CLDC was compared to gD2 + MPL/Alum. When the vaccine and adjuvants were evaluated as therapeutic vaccines, they were ineffective. CLDC enhanced protection compared to MPL/Alum and is the first vaccine to reduce recurrent virus shedding, a key to decreasing the spread of HSV-2. © 2009 Elsevier Ltd. All rights reserved. Source

Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 536.61K | Year: 2006

DESCRIPTION (provided by applicant): The overall purpose of this proposal is to determine the level of innate and adaptive immune activation (i.e., anti-viral Th1 cytokines, antibody and cellular immune responses) induced by cationic lipid-DNA (non-coding) complexes (CLDC) combined with whole-inactivated Simian Immunodeficiency Virus (SIV) virions (CLDC-SIVinact) in the Rhesus macaque monkey model. Evidence suggests that CLDC efficiently stimulate the innate and adaptive immune pathways by the presence of CpG and non-CpG motifs as well as other mechanisms yet to be determined. The current formulation of the product is effective at inducing systemic cytokine production as well as substantial humoral and cellular immune responses, particularly cytotoxic T lymphocyte (CTL) activity. The SIV-macaque model was chosen due to its immunological, virological, pathological and clinical similarities to Human Immunodeficiency Virus (HIV) infection in humans. A primary purpose of this proposal is to determine the effectiveness of CLDC adjuvant/immunostimulatory activity, which can subsequently be applied to specific virion, protein or peptide antigens of interest. The specific aims of this proposal are to: (1) characterize the innate immune activation induced in vitro by CLDC-SIVinact on Rhesus monkey PBMC, and (2) compare anti-SIV immune responses (i.e., innate and adaptive) in Rhesus macaques immunized with either CLDC-SIVinact or alum-SIVinact. Immunized monkeys will be analysed for innate immune cytokine responses as well as SIV-specific humoral and cellular immunity (i.e., antibody, T cell proliferation, CTL activity). Positive immunological results from the current study will provide the basis for a subsequent phase II proposal to evaluate the protection afforded by CLDC-SIVinact, in Rhesus macaques challenged with pathogenic SIV. The program will ultimately provide insight and knowledge toward the development of a novel immunostimulant/adjuvant for a prophylactic and/or therapeutic vaccine against HIV infection in humans.

Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 975.86K | Year: 2006

DESCRIPTION (provided by applicant): The overall purpose of this project is to investigate and develop a novel immune stimulant that can be used to elicit non-specific protection against pathogenic microorganisms that might be deployed in bioterrorist attacks. The product, comprised of cationic liposome-plasmid DNA complexes (CLDC), is an extremely potent stimulus for activation of innate immunity, particularly for release of interferons and other cytokines. The major advantages of CLDC relative to conventional immunostimulants are that they are more potent activators of interferon release, they can be administered by aerosol or mucosal delivery, they can be lyophilized and retain activity, and they are relatively simple and inexpensive to manufacture. The proposed studies are designed to test the hypothesis that CLDC can rapidly elicit sufficient protective innate immunity to be efficacious after parenteral or mucosal in an aerosol bacterial challenge rodent model. In preliminary studies, we have observed potent activation of innate immunity after administration of CLDC and efficacy after aerosol challenge with Mycobacterium tuberculosis. Complete protection has also been observed following intraperitoneal and intranasal administration of CLDC 48 hours prior to lethal intranasal challenge with Francisella tularensis LVS. We will, therefore, examine the effectiveness of CLDC-mediated immune activation by other routes of administration, particularly after mucosal delivery to the lungs and upper airways to evaluate protection against aerosol challenge with the more pathogenic F. tularensis Schu4. The specific goals of this project are (1) to determine how the route of administration and dosing regimen of CLDC affects the magnitude, quality, and duration of innate immune activation, and (2) determine the impact of CLDC-induced immunity on protection against F. tularensis challenge. We believe these studies will provide the basis for the CLDC' ability, in an easily administered format, to rapidly activate potent and consistent innate immune responses that will be essential in biodefense and civilian applications.

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