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Badamchi-Zadeh, Alexander

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Badamchi-Zadeh

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Alexander

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Badamchi-Zadeh, Alexander

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    Vaccine Protection Against Zika Virus from Brazil
    (2016) Larocca, Rafael; Abbink, Peter; Peron, Jean Pierre S.; de A. Zanotto, Paolo M.; Iampietro, M. Justin; Badamchi-Zadeh, Alexander; Boyd, Michael; Ng’ang’a, David; Kirilova, Marinela; Nityanandam, Ramya; Mercado, Noe B.; Li, Zhenfeng; Moseley, Edward T.; Bricault, Christine; Borducchi, Erica N.; Giglio, Patricia B.; Jetton, David; Neubauer, George; Nkolola, Joseph; Maxfield, Lori; De La Barrera, Rafael A.; Jarman, Richard G.; Eckels, Kenneth H.; Michael, Nelson L.; Thomas, Stephen J.; Barouch, Dan
    Zika virus (ZIKV) is a flavivirus that is responsible for an unprecedented current epidemic in Brazil and the Americas1,2. ZIKV has been causally associated with fetal microcephaly, intrauterine growth restriction, and other birth defects in both humans3–8 and mice9–11. The rapid development of a safe and effective ZIKV vaccine is a global health priority1,2, but very little is currently known about ZIKV immunology and mechanisms of immune protection. Here we show that a single immunization of a plasmid DNA vaccine or a purified inactivated virus vaccine provides complete protection in susceptible mice against challenge with a ZIKV outbreak strain from northeast Brazil. This ZIKV strain has recently been shown to cross the placenta and to induce fetal microcephaly and other congenital malformations in mice11. We produced DNA vaccines expressing full-length ZIKV pre-membrane and envelope (prM-Env) as well as a series of deletion mutants. The full-length prM-Env DNA vaccine, but not the deletion mutants, afforded complete protection against ZIKV as measured by absence of detectable viremia following challenge, and protective efficacy correlated with Env-specific antibody titers. Adoptive transfer of purified IgG from vaccinated mice conferred passive protection, and CD4 and CD8 T lymphocyte depletion in vaccinated mice did not abrogate protective efficacy. These data demonstrate that protection against ZIKV challenge can be achieved by single-shot subunit and inactivated virus vaccines in mice and that Env-specific antibody titers represent key immunologic correlates of protection. Our findings suggest that the development of a ZIKV vaccine for humans will likely be readily achievable.
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    Adenovirus Vector Vaccination Impacts NK Cell Rheostat Function following Lymphocytic Choriomeningitis Virus Infection
    (American Society for Microbiology, 2018) Blass, Eryn; Aid, Malika; Martinot, Amanda; Larocca, Rafael; Kang, Zi Han; Badamchi-Zadeh, Alexander; Penaloza-MacMaster, Pablo; Reeves, R. Keith; Barouch, Dan
    ABSTRACT Natural killer (NK) cells respond rapidly as a first line of defense against infectious pathogens. In addition, NK cells may provide a “rheostat” function and have been shown to reduce the magnitude of antigen-specific T cell responses following infection to avoid immunopathology. However, it remains unknown whether NK cells similarly modulate vaccine-elicited T cell responses following virus challenge. We used the lymphocytic choriomeningitis virus (LCMV) clone 13 infection model to address whether NK cells regulate T cell responses in adenovirus vector-vaccinated mice following challenge. As expected, NK cell depletion in unvaccinated mice resulted in increased virus-specific CD4+ and CD8+ T cell responses and immunopathology following LCMV challenge. In contrast, NK cell depletion had minimal to no impact on antigen-specific T cell responses in mice that were vaccinated with an adenovirus serotype 5 (Ad5)-GP vector prior to LCMV challenge. Moreover, NK cell depletion in vaccinated mice prior to challenge did not result in immunopathology and did not compromise protective efficacy. These data suggest that adenovirus vaccine-elicited T cells may be less sensitive to NK cell rheostat regulation than T cells primed by LCMV infection. IMPORTANCE: Recent data have shown that NK cell depletion leads to enhanced virus-elicited T cell responses that can result in severe immunopathology following LCMV infection in mice. In this study, we observed that NK cells exerted minimal to no impact on vaccine-elicited T cells following LCMV challenge, suggesting that adenovirus vaccine-elicited T cells may be less subject to NK cell regulation. These data contribute to our understanding of NK cell regulatory functions and T cell-based vaccines.
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    Therapeutic Efficacy of Vectored PGT121 Gene Delivery in HIV-1-Infected Humanized Mice
    (American Society for Microbiology, 2018) Badamchi-Zadeh, Alexander; Tartaglia, Lawrence; Abbink, Peter; Bricault, Christine; Liu, Po-Ting; Boyd, Michael; Kirilova, Marinela; Mercado, Noe B.; Nanayakkara, Ovini S.; Vrbanac, Vladimir D.; Tager, Andrew M.; Larocca, Rafael; Seaman, Michael; Barouch, Dan
    ABSTRACT Broadly neutralizing antibodies (bNAbs) are being explored for HIV-1 prevention and cure strategies. However, administration of purified bNAbs poses challenges in resource-poor settings, where the HIV-1 disease burden is greatest. In vivo vector-based production of bNAbs represents an alternative strategy. We investigated adenovirus serotype 5 (Ad5) and adeno-associated virus serotype 1 (AAV1) vectors to deliver the HIV-1-specific bNAb PGT121 in wild-type and immunocompromised C57BL/6 mice as well as in HIV-1-infected bone marrow-liver-thymus (BLT) humanized mice. Ad5.PGT121 and AAV1.PGT121 produced functional antibody in vivo. Ad5.PGT121 produced PGT121 rapidly within 6 h, whereas AAV1.PGT121 produced detectable PGT121 in serum by 72 h. Serum PGT121 levels were rapidly reduced by the generation of anti-PGT121 antibodies in immunocompetent mice but were durably maintained in immunocompromised mice. In HIV-1-infected BLT humanized mice, Ad5.PGT121 resulted in a greater reduction of viral loads than did AAV1.PGT121. Ad5.PGT121 also led to more-sustained virologic control than purified PGT121 IgG. Ad5.PGT121 afforded more rapid, robust, and durable antiviral efficacy than AAV1.PGT121 and purified PGT121 IgG in HIV-1-infected humanized mice. Further evaluation of vector delivery of HIV-1 bNAbs is warranted, although approaches to prevent the generation of antiantibody responses may also be required. IMPORTANCE: Broadly neutralizing antibodies (bNAbs) are being explored for HIV-1 prevention and cure strategies, but delivery of purified antibodies may prove challenging. We investigated adenovirus serotype 5 (Ad5) and adeno-associated virus serotype 1 (AAV1) vectors to deliver the HIV-1-specific bNAb PGT121. Ad5.PGT121 afforded more rapid, robust, and durable antiviral efficacy than AAV1.PGT121 and purified PGT121 IgG in HIV-1-infected humanized mice.
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    Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses
    (American Society for Microbiology, 2016) Provine, Nicholas M.; Badamchi-Zadeh, Alexander; Bricault, Christine; Penaloza-MacMaster, Pablo; Larocca, Rafael A.; Borducchi, Erica N.; Seaman, Michael; Barouch, Dan
    ABSTRACT We have recently demonstrated that CD4+ T cell help is required at the time of adenovirus (Ad) vector immunization for the development of functional CD8+ T cell responses, but the temporal requirement for CD4+ T cell help for the induction of antibody responses remains unclear. Here we demonstrate that induction of antibody responses in C57BL/6 mice can occur at a time displaced from the time of Ad vector immunization by depletion of CD4+ T cells. Transient depletion of CD4+ T cells at the time of immunization delays the development of antigen-specific antibody responses but does not permanently impair their development or induce tolerance against the transgene. Upon CD4+ T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals. These delayed antibody responses exhibit no functional defects with regard to isotype, functional avidity, expansion after boosting immunization, or the capacity to neutralize a simian immunodeficiency virus (SIV) Env-expressing pseudovirus. The development of this delayed transgene-specific antibody response is temporally linked to the expansion of de novo antigen-specific CD4+ T cell responses, which develop after transient depletion of CD4+ T cells. These data demonstrate that functional vaccine-elicited antibody responses can be induced even if CD4+ T cell help is provided at a time markedly separated from the time of vaccination. IMPORTANCE: CD4+ T cells have a critical role in providing positive help signals to B cells, which promote robust antibody responses. The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen. Here we demonstrate that, in contrast to the current model that the absence of CD4+ T cell help at priming results in long-term antibody nonresponsiveness, antibody responses can be induced by adenovirus vector immunization or alum-adjuvanted protein immunization even if CD4+ T cell help is not provided until >1 month after immunization. These data demonstrate that the time when CD4+ T cell help signals must be provided is more dynamic and flexible than previously appreciated. These data suggest that augmentation of CD4+ T cell helper function even after the time of vaccination can enhance vaccine-elicited antibody responses and thereby potentially enhance the immunogenicity of vaccines in immunocompromised individuals.
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    Rapid Cloning of Novel Rhesus Adenoviral Vaccine Vectors
    (American Society for Microbiology, 2018) Abbink, Peter; Kirilova, Marinela; Boyd, Michael; Mercado, Noe; Li, Zhenfeng; Nityanandam, Ramya; Nanayakkara, Ovini; Peterson, Rebecca; Larocca, Rafael; Aid, Malika; Tartaglia, Lawrence; Mutetwa, Tinaye; Blass, Eryn; Jetton, David; Maxfield, Lori; Borducchi, Erica N.; Badamchi-Zadeh, Alexander; Handley, Scott; Zhao, Guoyan; Virgin, Herbert W.; Havenga, Menzo J.; Barouch, Dan
    ABSTRACT Human and chimpanzee adenovirus vectors are being developed to circumvent preexisting antibodies against common adenovirus vectors such as Ad5. However, baseline immunity to these vectors still exists in human populations. Traditional cloning of new adenovirus vaccine vectors is a long and cumbersome process that takes 2 months or more and that requires rare unique restriction enzyme sites. Here we describe a novel, restriction enzyme-independent method for rapid cloning of new adenovirus vaccine vectors that reduces the total cloning procedure to 1 week. We developed 14 novel adenovirus vectors from rhesus monkeys that can be grown to high titers and that are immunogenic in mice. All vectors grouped with the unusual adenovirus species G and show extremely low seroprevalence in humans. Rapid cloning of novel adenovirus vectors is a promising approach for the development of new vector platforms. Rhesus adenovirus vectors may prove useful for clinical development. IMPORTANCE: To overcome baseline immunity to human and chimpanzee adenovirus vectors, we developed 14 novel adenovirus vectors from rhesus monkeys. These vectors are immunogenic in mice and show extremely low seroprevalence in humans. Rhesus adenovirus vectors may prove useful for clinical development.