IL-2-engineered nano-APC effectively activates viral antigen-mediated T cell responses from chronic hepatitis B virus-infected patients

J Immunol. 2012 Feb 1;188(3):1534-43. doi: 10.4049/jimmunol.1102709. Epub 2011 Dec 30.

Abstract

Impaired function of virus-specific T cells resulting from virus persistence is one of the major mechanisms underlying the development of chronic hepatitis B viral infection. Previously, we found that IL-2 can restore the effector function of T cells rendered tolerant by Ag persistence. However, systemic administration of IL-2 induces organ pathology and expansion of T regulatory cells. In this study, we show that nano-APC with engineered HLA alleles and IL-2 deliver peptide-MHC complexes, costimulatory molecules, and IL-2 to Ag-responding T cells, resulting in enhanced expression of CD25 and activation of TCR signaling pathways, while suppressing PD-1 expression on viral-responding CD8 T cells from chronic hepatitis B virus patients. The enhanced activation of CD4 and CD8 T cells induced by IL-2-nano-APC was Ag dependent and IL-2-nano-APC did not affect T regulatory cells. At a size of 500 nm, the nano-APC effectively induce immune synapse formation on Ag-specific T cells and accumulate as free particles in the lymphoid organs. These attributes of IL-2-nano-APC or other bioadjuvant-engineered nano-APC have profound implications for their use as a therapeutic strategy in the treatment of chronic hepatitis B virus infection or other chronic viral diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / drug effects*
  • Antigens, Viral / immunology
  • Hepatitis B, Chronic / drug therapy*
  • Hepatitis B, Chronic / immunology
  • Humans
  • Interleukin-2 / administration & dosage*
  • Lymphocyte Activation / drug effects*
  • Nanoparticles / therapeutic use
  • Protein Engineering
  • T-Lymphocytes / immunology*

Substances

  • Antigens, Viral
  • Interleukin-2