1. Releasing the Brakes on Cancer Immunotherapy
Dan R. Littman 
Cell 
Volume 162, Issue 6, Pages (September 2015)
DOI: /j.cell
Copyright © 2015 Elsevier Inc. Terms and Conditions

2. Figure 1
Activation of Anti-Tumor Cytotoxic T Cells by Blockade of CTLA-4
Proposed mechanisms for the activity of anti-CTLA-4 antibody in releasing inhibition of tumor cell killing by CD8+ T cells. (Pathway 1) Indirect mechanism through inhibition of regulatory T cell (Treg) accumulation in tumors, which requires binding of antibody to Fc receptor on innate immune cells and is mediated by antibody-dependent cellular cytotoxicity. (Pathway 2) Direct activity on cytotoxic T lymphocytes through inhibition of CTLA-4 interaction with B7-1 and B7-2 on antigen-presenting dendritic cells, thereby increasing CD28 co-stimulatory activity and/or reducing CTLA-4 inhibitory signaling. Note that tumor peptide antigen is cross-presented to CTL by dendritic cells, and direct interaction of T cells with tumor cells may result in anergy through the T cell receptor (TCR).
Cell  , DOI: ( /j.cell )
Copyright © 2015 Elsevier Inc. Terms and Conditions