Vaccine protocols for enhanced immunogenicity of exogenous antigens

Int J Med Microbiol. 2008 Jan;298(1-2):27-32. doi: 10.1016/j.ijmm.2007.08.004. Epub 2007 Sep 20.

Abstract

Vaccination protocols aim at the delivery of exogenous antigen (Ag) to antigen-presenting cells (APCs) concurrent with the activation of APCs by adjuvants. Activated APCs then cross-present the Ag, cross-prime T effector cells, and activate B cells. Classical protocols rely on a mixture of both Ag and the adjuvant. However, a disadvantage of this strategy is that simultaneous "loading" and activation of APCs is not guaranteed. As a consequence, heterogeneous APC populations will be generated, including APCs being either Ag-presenting or only activated, thus rendering the adaptive immune response suboptimal. Therefore, novel strategies are needed that provide both constituents to the same APC in order to generate a homogeneous Ag-presenting and activated cell population. Here we show that these requirements can be fulfilled via two distinct methods, either by covalently linking Ag to the adjuvant or by co-encapsulating Ag and adjuvant into biodegradable microparticles. These novel vaccine protocols allow the generation of robust T-cell and B-cell responses that match immunogenicity of live vectors. Their characteristics with regard to efficacy, flexibility, and clinical applicability are discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adjuvants, Immunologic / pharmacology*
  • Antigen Presentation / immunology*
  • Antigen-Presenting Cells / immunology
  • Antigens / immunology*
  • Humans
  • Microspheres
  • Oligodeoxyribonucleotides / immunology
  • T-Lymphocytes / immunology
  • Toll-Like Receptor 9 / immunology
  • Vaccination / methods*
  • Vaccines / immunology*

Substances

  • Adjuvants, Immunologic
  • Antigens
  • CPG-oligonucleotide
  • Oligodeoxyribonucleotides
  • Toll-Like Receptor 9
  • Vaccines