Polyanhydride particle platform for design of novel influenza vaccines

Vaccines remain the most effective medical intervention to disease in which effective vaccines are available. Designing vaccines that elicit protective immunity while minimizing adverse events is difficult. Exacerbating the challenges of vaccine design is the increased emphasis on using pure preparation of antigens that alleviate safety concerns but also show decreased potency. Therefore the need for safe adjuvants to boost immunity of subunit immunizations is great. This work demonstrates the capability of a novel bio-erodible polyanhydride particle platform to enhance humoral and cellular immunity. Encapsulation of 25 µg of Ovalbumin (Ova) antigen in microparticles elicits humoral immune responses equivalent to 1600, 400, and 100 µg dosages of Ova. Characterizing the persistence of the nanoparticle platform shows that in vivo persistence and immunomodulatory activity can be tailored by altering copolymer chemistry. Polyanhydride nanoparticle vaccines against Ova show an increased ability to expand CD8+ T cells as compared to Alum and soluble Ova. These same polyanhydride nanoparticle vaccines expand CD4+ T cells and promote a T follicular helper (CXCR5high PD-1high) cell phenotype important for germinal center formation. The polyanhydride platform designed vaccines against H5N1 using a stabilized trimeric H5 antigen were evaluated in multiple dose and route regimens and elicit neutralizing antibody activity and expanded CD4+ cellular recall responses when administered subcutaneously. These results demonstrate that the polyanhydride particle platform can be used to effectively enhance immune responses in subunit immunizations

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Hemagglutinin-based polyanhydride nanovaccines against H5N1 influenza elicit protective virus neutralizing titers and cell-mediated immunity

H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H53) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H53 antigen was a robust immunogen. Immunizing mice with H53 encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4+ T cell recall responses in mice. Finally, the H53-based polyanhydride nanovaccine induced protective immunity against a low-pathogenic H5N1 viral challenge. Informatics analyses indicated that mice receiving the nanovaccine formulations and subsequently challenged with virus were similar to naïve mice that were not challenged. The current studies provide a basis to further exploit the advantages of polyanhydride nanovaccines in pandemic scenarios

Hemagglutinin-based polyanhydride nanovaccines against H5N1 influenza elicit protective virus neutralizing titers and cell-mediated immunity.

H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H5₃) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H5₃ antigen was a robust immunogen. Immunizing mice with H5₃ encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4(+) T cell recall responses in mice. Finally, the H5₃-based polyanhydride nanovaccine induced protective immunity against a low-pathogenic H5N1 viral challenge. Informatics analyses indicated that mice receiving the nanovaccine formulations and subsequently challenged with virus were similar to naïve mice that were not challenged. The current studies provide a basis to further exploit the advantages of polyanhydride nanovaccines in pandemic scenarios

Polyanhydride particle platform for design of novel influenza vaccines

Vaccines remain the most effective medical intervention to disease in which effective vaccines are available. Designing vaccines that elicit protective immunity while minimizing adverse events is difficult. Exacerbating the challenges of vaccine design is the increased emphasis on using pure preparation of antigens that alleviate safety concerns but also show decreased potency. Therefore the need for safe adjuvants to boost immunity of subunit immunizations is great. This work demonstrates the capability of a novel bio-erodible polyanhydride particle platform to enhance humoral and cellular immunity. Encapsulation of 25 µg of Ovalbumin (Ova) antigen in microparticles elicits humoral immune responses equivalent to 1600, 400, and 100 µg dosages of Ova. Characterizing the persistence of the nanoparticle platform shows that in vivo persistence and immunomodulatory activity can be tailored by altering copolymer chemistry. Polyanhydride nanoparticle vaccines against Ova show an increased ability to expand CD8+ T cells as compared to Alum and soluble Ova. These same polyanhydride nanoparticle vaccines expand CD4+ T cells and promote a T follicular helper (CXCR5high PD-1high) cell phenotype important for germinal center formation. The polyanhydride platform designed vaccines against H5N1 using a stabilized trimeric H5 antigen were evaluated in multiple dose and route regimens and elicit neutralizing antibody activity and expanded CD4+ cellular recall responses when administered subcutaneously. These results demonstrate that the polyanhydride particle platform can be used to effectively enhance immune responses in subunit immunizations.</p

Harvesting Murine Alveolar Macrophages and Evaluating Cellular Activation Induced by Polyanhydride Nanoparticles

Biodegradable nanoparticles have emerged as a versatile platform for the design and implementation of new intranasal vaccines against respiratory infectious diseases. Specifically, polyanhydride nanoparticles composed of the aliphatic sebacic acid (SA), the aromatic 1,6-bis(p-carboxyphenoxy)hexane (CPH), or the amphiphilic 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) display unique bulk and surface erosion kinetics1,2 and can be exploited to slowly release functional biomolecules (e.g., protein antigens, immunoglobulins, etc.) in vivo3,4,5. These nanoparticles also possess intrinsic adjuvant activity, making them an excellent choice for a vaccine delivery platform6,7,8. In order to elucidate the mechanisms governing the activation of innate immunity following intranasal mucosal vaccination, one must evaluate the molecular and cellular responses of the antigen presenting cells (APCs) responsible for initiating immune responses. Dendritic cells are the principal APCs found in conducting airways, while alveolar macrophages (AMɸ) predominate in the lung parenchyma9,10,11. AMɸ are highly efficient in clearing the lungs of microbial pathogens and cell debris12,13. In addition, this cell type plays a valuable role in the transport of microbial antigens to the draining lymph nodes, which is an important first step in the initiation of an adaptive immune response9. AMɸ also express elevated levels of innate pattern recognition and scavenger receptors, secrete pro-inflammatory mediators, and prime naïve T cells12,14. A relatively pure population of AMɸ (e.g., greater than 80%) can easily be obtained via lung lavage for study in the laboratory. Resident AMɸ harvested from immune competent animals provide a representative phenotype of the macrophages that will encounter the particle-based vaccine in vivo. Herein, we describe the protocols used to harvest and culture AMɸ from mice and examine the activation phenotype of the macrophages following treatment with polyanhydride nanoparticles in vitro

Harvesting murine alveolar macrophages and evaluating cellular activation induced by polyanhydride nanoparticles.

Biodegradable nanoparticles have emerged as a versatile platform for the design and implementation of new intranasal vaccines against respiratory infectious diseases. Specifically, polyanhydride nanoparticles composed of the aliphatic sebacic acid (SA), the aromatic 1,6-bis(p-carboxyphenoxy)hexane (CPH), or the amphiphilic 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) display unique bulk and surface erosion kinetics and can be exploited to slowly release functional biomolecules (e.g., protein antigens, immunoglobulins, etc.) in vivo. These nanoparticles also possess intrinsic adjuvant activity, making them an excellent choice for a vaccine delivery platform. In order to elucidate the mechanisms governing the activation of innate immunity following intranasal mucosal vaccination, one must evaluate the molecular and cellular responses of the antigen presenting cells (APCs) responsible for initiating immune responses. Dendritic cells are the principal APCs found in conducting airways, while alveolar macrophages (AMΦ) predominate in the lung parenchyma. AMΦ are highly efficient in clearing the lungs of microbial pathogens and cell debris. In addition, this cell type plays a valuable role in the transport of microbial antigens to the draining lymph nodes, which is an important first step in the initiation of an adaptive immune response. AMΦ also express elevated levels of innate pattern recognition and scavenger receptors, secrete pro-inflammatory mediators, and prime naïve T cells. A relatively pure population of AMΦ (e.g., greater than 80%) can easily be obtained via lung lavage for study in the laboratory. Resident AMΦ harvested from immune competent animals provide a representative phenotype of the macrophages that will encounter the particle-based vaccine in vivo. Herein, we describe the protocols used to harvest and culture AMΦ from mice and examine the activation phenotype of the macrophages following treatment with polyanhydride nanoparticles in vitro.This article is from Journal of Visualized Experiments 64 (2012): e3883, doi: 10.3791/3883.</p

Combinatorial evaluation of in vivo distribution of polyanhydride particle-based platforms for vaccine delivery

Several challenges are associated with current vaccine strategies, including repeated immunizations, poor patient compliance, and limited approved routes for delivery, which may hinder induction of protective immunity. Thus, there is a need for new vaccine adjuvants capable of multi-route administration and prolonged antigen release at the site of administration by providing a depot within tissue. In this work, we designed a combinatorial platform to investigate the in vivo distribution, depot effect, and localized persistence of polyanhydride nanoparticles as a function of nanoparticle chemistry and administration route. Our observations indicated that the route of administration differentially affected tissue residence times. All nanoparticles rapidly dispersed when delivered intranasally but provided a depot when administered parenterally. When amphiphilic and hydrophobic nanoparticles were administered intranasally, they persisted within lung tissue. These results provide insights into the chemistry and route-dependent distribution and tissue-specific association of polyanhydride nanoparticle-based vaccine adjuvants.This article is from International Journal of Nanomedicine 8 (2013): 2213, doi: 10.2147/IJN.S45317.</p

Hemagglutinin-based polyanhydride nanovaccines against H5N1 influenza elicit protective virus neutralizing titers and cell-mediated immunity

H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H53) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H53 antigen was a robust immunogen. Immunizing mice with H53 encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4+ T cell recall responses in mice. Finally, the H53-based polyanhydride nanovaccine induced protective immunity against a low-pathogenic H5N1 viral challenge. Informatics analyses indicated that mice receiving the nanovaccine formulations and subsequently challenged with virus were similar to naïve mice that were not challenged. The current studies provide a basis to further exploit the advantages of polyanhydride nanovaccines in pandemic scenarios.This article is from International Journal of Nanomedicine 10 (2015): 229, doi: 10.2147/IJN.S72264. Posted with permission.</p