Surfactant-free anionic PLA nanoparticles coated with HIV-1 p24 protein induced enhanced cellular and humoral immune responses in various animal models.

Microparticles and nanoparticles prepared with poly(D,L-lactide-co-glycolide) (PLGA) or poly(D,L-lactide) (PLA) polymers represent a promising method for in vivo delivery of encapsulated peptide, protein or DNA antigens. However, one major issue that limits the potential of these delivery systems is the instability or the degradation of the entrapped antigen. Charged microparticles carrying surface adsorbed antigen were developed to resolve this problem and appear more suitable for vaccine applications. We describe here new anionic PLA nanoparticles obtained by the dialysis method that are absolutely surfactant-free, which makes them more appropriate for use in humans. The potency of this delivery system as a vaccine carrier was tested in various animal models using HIV-1 p24 protein. p24-coated PLA nanoparticles (p24/PLA) induced high antibody titres (>10(6)) in mice, rabbits and macaques. Moreover, p24/PLA nanoparticles elicited strong CTL responses and a Th1-biased cytokine release (IFNgamma, IL-2) in mice. p24 protein seemed to generate a more Th1-oriented response when administered coated onto the surface of PLA nanoparticles than adjuvanted with Freund's adjuvant. Most importantly, the ability of p24/PLA particles to induce Th1 responses was also confirmed in the macaque model, since high levels of IFNgamma-producing CD4+ T cells and CD8+ T cells could be detected by the ELISPOT assay. This protein delivery system confirms the potential of charged nanoparticles in the field of vaccine development.

[1]  T. Delair,et al.  Cationic PLA nanoparticles for DNA delivery: comparison of three surface polycations for DNA binding, protection and transfection properties. , 2005, Colloids and surfaces. B, Biointerfaces.

[2]  H. Merkle,et al.  Immobilisation of GM-CSF onto particulate vaccine carrier systems. , 2004, International journal of pharmaceutics.

[3]  B. Gander,et al.  Revisiting PLA/PLGA microspheres: an analysis of their potential in parenteral vaccination. , 2000, European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V.

[4]  Hans P Merkle,et al.  Formulation aspects of biodegradable polymeric microspheres for antigen delivery. , 2005, Advanced drug delivery reviews.

[5]  D. O'hagan,et al.  Induction of mucosal and systemic immune responses by immunization with ovalbumin entrapped in poly(lactide-co-glycolide) microparticles. , 1994, Immunology.

[6]  J. Nah,et al.  Effect of solvent on the preparation of surfactant-free poly(DL-lactide-co-glycolide) nanoparticles and norfloxacin release characteristics. , 2000, International journal of pharmaceutics.

[7]  Y. Ohya,et al.  Preparation of poly(L-lactide)-based microspheres having a cationic or anionic surface using biodegradable surfactants. , 2002, Biomacromolecules.

[8]  A. Almeida,et al.  Immune Response to Nasal Delivery of Antigenically Intact Tetanus Toxoid Associated with Poly(l‐lactic acid) Microspheres in Rats, Rabbits and Guinea‐pigs , 1993, The Journal of pharmacy and pharmacology.

[9]  R. Mumper,et al.  Coating of cationized protein on engineered nanoparticles results in enhanced immune responses. , 2002, International journal of pharmaceutics.

[10]  M. Pizza,et al.  Anionic microparticles are a potent delivery system for recombinant antigens from Neisseria meningitidis serotype B. , 2004, Journal of pharmaceutical sciences.

[11]  Wenlei Jiang,et al.  Biodegradable poly(lactic-co-glycolic acid) microparticles for injectable delivery of vaccine antigens. , 2005, Advanced drug delivery reviews.

[12]  M. Hedley,et al.  Microspheres containing plasmid-encoded antigens elicit cytotoxic T-cell responses , 1998, Nature Medicine.

[13]  Manmohan J. Singh,et al.  Controlled Delivery of Diphtheria Toxoid Using Biodegradable Poly(D,L-Lactide) Microcapsules , 1991, Pharmaceutical Research.

[14]  D. Rahman,et al.  Biodegradable microparticles as controlled release antigen delivery systems. , 1991, Immunology.

[15]  T. Delair,et al.  Poly(d,l-lactic acid) and chitosan complexes: interactions with plasmid DNA , 2005 .

[16]  G. Ott,et al.  Novel anionic microparticles are a potent adjuvant for the induction of cytotoxic T lymphocytes against recombinant p55 gag from HIV-1. , 2000, Journal of controlled release : official journal of the Controlled Release Society.

[17]  G. Altavilla,et al.  Novel biocompatible anionic polymeric microspheres for the delivery of the HIV-1 Tat protein for vaccine application. , 2004, Vaccine.

[18]  J. Clements,et al.  Identification of a peptide capable of inducing an HIV-1 Tat-specific CTL response. , 2001, Vaccine.

[19]  D. Sesardic,et al.  European union regulatory developments for new vaccine adjuvants and delivery systems. , 2004, Vaccine.

[20]  P. Travers,et al.  The MHC class I-restricted immune response to HIV-gag in BALB/c mice selects a single epitope that does not have a predictable MHC-binding motif and binds to Kd through interactions between a glutamine at P3 and pocket D. , 1998, Journal of immunology.

[21]  Gupta,et al.  Aluminum compounds as vaccine adjuvants. , 1998, Advanced drug delivery reviews.

[22]  H. Okada,et al.  Biodegradable microspheres in drug delivery. , 1995, Critical reviews in therapeutic drug carrier systems.

[23]  Russell J Mumper,et al.  Strong T cell type-1 immune responses to HIV-1 Tat (1-72) protein-coated nanoparticles. , 2004, Vaccine.

[24]  B. Verrier,et al.  Overexpression of HIV-1 proteins in Escherichia coli by a modified expression vector and their one-step purification. , 1993, Protein expression and purification.

[25]  E. Hundt,et al.  Tetanus Toxoid Loaded Nanoparticles from Sulfobutylated Poly(Vinyl Alcohol)-Graft-Poly(Lactide-co-Glycolide): Evaluation of Antibody Response After Oral and Nasal Application in Mice , 2001, Pharmaceutical Research.

[26]  S. Davis,et al.  PLGA nanoparticles prepared by nanoprecipitation: drug loading and release studies of a water soluble drug. , 1999, Journal of controlled release : official journal of the Controlled Release Society.

[27]  J. Ulmer,et al.  Induction of Potent Immune Responses by Cationic Microparticles with Adsorbed Human Immunodeficiency Virus DNA Vaccines , 2001, Journal of Virology.

[28]  T. Delair,et al.  One-step cationic poly(D,L-lactic acid) particle synthesis by diafiltration and interactions with plasmid DNA , 2005 .

[29]  Manmohan J. Singh,et al.  Charged polylactide co-glycolide microparticles as antigen delivery systems , 2004, Expert opinion on biological therapy.

[30]  J. Mcghee,et al.  Biodegradable microspheres as a vaccine delivery system. , 1991, Molecular immunology.

[31]  J. Ulmer,et al.  Induction of Broad and Potent Anti-Human Immunodeficiency Virus Immune Responses in Rhesus Macaques by Priming with a DNA Vaccine and Boosting with Protein-Adsorbed Polylactide Coglycolide Microparticles , 2003, Journal of Virology.