Selection of an antibody library identifies a pathway to induce immunity by targeting CD36 on steady-state CD8 alpha+ dendritic cells

J Immunol. 2008 Mar 1;180(5):3201-9. doi: 10.4049/jimmunol.180.5.3201.

Abstract

Improvement of the strategy to target tumor Ags to dendritic cells (DCs) for immunotherapy requires the identification of the most appropriate ligand/receptor pairing. We screened a library of Ab fragments on mouse DCs to isolate new potential Abs capable of inducing protective immune responses. The screening identified a high-affinity Ab against CD36, a multi-ligand scavenger receptor primarily expressed by the CD8alpha+ subset of conventional DCs. The Ab variable regions were genetically linked to the model Ag OVA and tested in Ag presentation assays in vitro and in vivo. Anti-CD36-OVA was capable of delivering exogenous Ags to the MHC class I and MHC class II processing pathways. In vivo, immunization with anti-CD36-OVA induced robust activation of naive CD4+ and CD8+ Ag-specific T lymphocytes and the differentiation of primed CD8+ T cells into long-term effector CTLs. Vaccination with anti-CD36-OVA elicited humoral and cell-mediated protection from the growth of an Ag-specific tumor. Notably, the relative efficacy of targeting CD11c/CD8alpha+ via CD36 or DEC205 was qualitatively different. Anti-DEC205-OVA was more efficient than anti-CD36-OVA in inducing early events of naive CD8+ T cell activation. In contrast, long-term persistence of effector CTLs was stronger following immunization with anti-CD36-OVA and did not require the addition of exogenous maturation stimuli. The results identify CD36 as a novel potential target for immunotherapy and indicate that the outcome of the immune responses vary by targeting different receptors on CD8alpha+ DCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / physiology*
  • Antigen Presentation / genetics
  • Antigen Presentation / immunology*
  • CD36 Antigens / immunology
  • CD36 Antigens / metabolism
  • CD36 Antigens / physiology*
  • CD8 Antigens / biosynthesis*
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Cross-Priming / genetics
  • Cross-Priming / immunology
  • Dendritic Cells / cytology
  • Dendritic Cells / immunology*
  • Dendritic Cells / metabolism*
  • Endocytosis / genetics
  • Endocytosis / immunology
  • Female
  • Histocompatibility Antigens Class I / biosynthesis
  • Histocompatibility Antigens Class II / biosynthesis
  • Immunoglobulin Fab Fragments / genetics
  • Immunoglobulin Fab Fragments / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Ovalbumin / immunology
  • Ovalbumin / metabolism
  • Peptide Library*
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / genetics
  • Signal Transduction / immunology*

Substances

  • Antibodies, Monoclonal
  • CD36 Antigens
  • CD8 Antigens
  • CD8alpha antigen
  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II
  • Immunoglobulin Fab Fragments
  • Peptide Library
  • Recombinant Fusion Proteins
  • Ovalbumin