Dendritic cell function after gene transfer with adenovirus-calcium phosphate co-precipitates

Mol Ther. 2007 Feb;15(2):386-92. doi: 10.1038/


Dendritic cells (DCs) are essential for initiating and directing antigen-specific T-cell responses. Genetic modification of DC is under study for cancer immunotherapy, vaccine development, and antigen-targeted immunosuppression. Adenovirus (Ad) type 5 (Ad5)-mediated gene transfer to mouse bone marrow DCs and human monocyte-derived DCs is inefficient because neither express the cognate high-affinity Ads receptor. We show that co-precipitating adenoviral vectors with calcium phosphate (CaPi) increased gene expression (2000-fold) and transduction efficiency (50-fold) in mouse DC, primarily owing to receptor-independent viral uptake. Moreover, Ad5:CaPi-treated DCs were activated to express the maturation surface molecules CD40 and CD86, and to secrete proinflammatory cytokines tumor necrosis factor-alpha and interleukin 6. However, neither DC transduction nor maturation was dependent on viral protein interactions with cell surface integrin. Ad5:CaPi also transduced human DC more efficiently than Ad5 alone, similar to a genetically modified vector (Ad5f35) targeted to the CD46 receptor. As such, this approach combines the efficiency of adenoviral-mediated endosomal escape and nuclear trafficking with the receptor independence of nonviral gene delivery. Importantly, CaPi co-precipitation could be used to functionally modify DC to activate and expand cytomegalovirus-specific memory cytotoxic T lymphocytes. This study identifies a simple technique to improve the efficacy of current Ad5 gene transfer, in support of clinical adoptive immunotherapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics*
  • Animals
  • Bone Marrow Cells / cytology
  • Bone Marrow Cells / metabolism
  • Calcium Phosphates / pharmacology*
  • Capsid Proteins / genetics
  • Capsid Proteins / metabolism
  • Dendritic Cells / drug effects
  • Dendritic Cells / metabolism*
  • Female
  • Flow Cytometry
  • Genetic Vectors / genetics
  • Humans
  • Integrins / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Protein Binding
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / metabolism
  • Transfection / methods*


  • Calcium Phosphates
  • Capsid Proteins
  • Integrins
  • calcium phosphate