CD40 activation in vivo overcomes peptide-induced peripheral cytotoxic T-lymphocyte tolerance and augments anti-tumor vaccine efficacy.
The outcome of antigen recognition by naive CD8+ cytotoxic T lymphocytes (CTLs) in the periphery is orchestrated by CD4+ T-helper cells, and can either lead to priming or tolerization. The presence of T-helper cells favors the induction of CTL immunity, whereas the absence of T-helper cells can result in CTL tolerance. The action of T helper cells in CTL priming is mediated by CD40-CD40 ligand interactions. We demonstrate here that triggering of CD40 in vivo can considerably enhance the efficacy of peptide-based anti-tumor vaccines. The combination of a tolerogenic peptide vaccine containing a minimal essential CTL epitope with an activating antibody against CD40 converts tolerization into strong CTL priming. Moreover, CD40 ligation can provide an already protective tumor-specific peptide vaccine with the capacity to induce therapeutic CTL immunity in tumor-bearing mice. These findings indicate that the CD40-CD40 ligand pair can act as a 'switch', determining whether naive peripheral CTLs are primed or tolerized, and support the clinical use of CD40-stimulating agents as components of anti-cancer vaccines.
Diehl
L
L
Department of Immunohematology and Bloodbank, Leiden University Medical Center, The Netherlands.
den Boer
A T
AT
Schoenberger
S P
SP
van der Voort
E I
EI
Schumacher
T N
TN
Melief
C J
CJ
Offringa
R
R
Toes
R E
RE
D017500:Adenovirus E1A Proteins / Q000276:immunology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000235:genetics / Q000502:physiology*; D023201:CD40 Ligand; D019496:Cancer Vaccines; D002471:Cell Transformation, Neoplastic; D000939:Epitopes / Q000276:immunology; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009374:Neoplasms, Experimental / Q000276:immunology / Q000517:prevention & control*; D010446:Peptide Fragments / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D017500:Adenovirus E1A Proteins; D019013:CD40 Antigens; D019496:Cancer Vaccines; D000939:Epitopes; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D023201:CD40 Ligand