title: TLR3 agonists improve the immunostimulatory potential of cetuximab against EGFR+head and neck cancer cells.
abstract: Toll-like receptor 3 (TLR3) agonists have been extensively used as adjuvants for anticancer vaccines. However, their immunostimulatory effects and precise mechanisms of action in the presence of antineoplastic monoclonal antibodies (mAbs) have not yet been evaluated. We investigated the effect of TLR3 agonists on cetuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) against head and neck cancer (HNC) cells, as well as on dendritic cell (DC) maturation and cross-priming of epidermal growth factor receptor (EGFR)-specific CD8+T cells. The cytotoxic activity of peripheral blood mononuclear cells (PBMCs) or isolated natural killer (NK) cells expressing polymorphic variants (at codon 158) of the Fcγ receptor IIIa (FcγIIIa) was determined in51Cr release assays upon incubation with the TLR3 agonist poly-ICLC. NK cell stimulation was measured based on activation and degranulation markers, while DC maturation in the presence of poly-ICLC was assessed using flow cytometry. The DC-mediated cross priming of EGFR-specific CD8+T cells was monitored upon in vitro stimulation with tetramer-based flow cytometry. TLR3-stimulated, unfractionated PBMCs from HNC patients mediated robust cetuximab-dependent ADCC, which was abrogated by NK-cell depletion. The cytolytic activity of TLR3-stimulated NK cells differed among cells expressing different polymorphic variants of FcγRIIIa, and NK cells exposed to both poly-ICLC and cetuximab expressed higher levels of CD107a and granzyme B than their counterparts exposed to either stimulus alone. Poly-ICLC plus cetuximab also induced a robust upregulation of CD80, CD83 and CD86 on the surface of DCs, a process that was partially NK-cell dependent. Furthermore, DCs matured in these conditions exhibited improved cross-priming abilities, resulting in higher numbers of EGFR-specific CD8+T cells. These findings suggest that TLR3 agonists may provide a convenient means to improve the efficacy of mAb-based anticancer regimens.
authors.affiliation: Department of Otolaryngology; University of Pittsburgh Medical Center; Pittsburgh, PA USA ; Department of Immunology; University of Pittsburgh Cancer Center; Pittsburgh, PA USA ; Department of Otolaryngology-Head and Neck Surgery; National University Health System; Singapore.
authors.forename: Chwee
authors.initials: C
authors.lastname: Ming Lim
authors.forename: Ryan
authors.initials: R
authors.lastname: Stephenson
authors.forename: Andres M
authors.initials: AM
authors.lastname: Salazar
authors.forename: Robert L
authors.initials: RL
authors.lastname: Ferris
keywords: ADCC; EGFR-specific CD8+ T cells; TLR3; cetuximab-activated NK cells; cross-priming; poly-ICLC
references.citation: J Clin Oncol. 2007 Aug 20;25(24):3712-8
references.pmid: 17704420
references.citation: Immunotherapy. 2010 Mar;2(2):137-40
references.pmid: 20635920
references.citation: Clin Microbiol Rev. 2008 Jan;21(1):13-25
references.pmid: 18202435
references.citation: J Immunol. 2010 Aug 15;185(4):2080-8
references.pmid: 20639488
references.citation: Cancer Immunol Immunother. 2009 Nov;58(11):1853-64
references.pmid: 19319529
references.citation: J Immunother. 2012 Jun;35(5):367-73
references.pmid: 22576341
references.citation: Lancet Oncol. 2010 Jan;11(1):21-8
references.pmid: 19897418
references.citation: J Clin Oncol. 2006 Oct 20;24(30):4914-21
references.pmid: 17050875
references.citation: Clin Cancer Res. 2006 Jul 15;12(14 Pt 2):4432s-4435s
references.pmid: 16857823
references.citation: Proc Natl Acad Sci U S A. 2008 Feb 19;105(7):2574-9
references.pmid: 18256187
references.citation: J Infect Dis. 1975 Oct;132(4):434-9
references.pmid: 810520
references.citation: Eur J Immunol. 2009 Oct;39(10):2877-84
references.pmid: 19728309
references.citation: Adv Drug Deliv Rev. 2008 Apr 29;60(7):813-23
references.pmid: 18241955
references.citation: J Immunol. 2006 Mar 15;176(6):3402-9
references.pmid: 16517708
references.citation: Proc Natl Acad Sci U S A. 1967 Sep;58(3):1004-10
references.pmid: 5233831
references.citation: J Mol Diagn. 2010 Jul;12(4):493-7
references.pmid: 20413676
references.citation: J Neurooncol. 2009 Jan;91(2):175-82
references.pmid: 18797818
references.citation: Cancer Res. 2010 Apr 1;70(7):2595-603
references.pmid: 20233880
references.citation: Clin Cancer Res. 2013 Apr 1;19(7):1858-72
references.pmid: 23444227
references.citation: J Gastroenterol. 2010 Apr;45(4):451-8
references.pmid: 19936602
references.citation: Leukemia. 2006 Jun;20(6):1130-7
references.pmid: 16628189
references.citation: J Immunol. 2011 Feb 15;186(4):2422-9
references.pmid: 21242525
references.citation: J Neurooncol. 2009 Jan;91(2):183-9
references.pmid: 18850068
references.citation: Breast Cancer Res Treat. 2009 Sep;117(1):83-9
references.pmid: 19051009
references.citation: J Immunol. 2005 Aug 1;175(3):1619-27
references.pmid: 16034101
references.citation: Clin Cancer Res. 2006 Jul 1;12(13):3890-5
references.pmid: 16818683
references.citation: Nat Immunol. 2004 Oct;5(10):987-95
references.pmid: 15454922
references.citation: J Immunother. 2009 Jun;32(5):465-73
references.pmid: 19609238
references.citation: Arch Otolaryngol Head Neck Surg. 2007 Dec;133(12):1277-81
references.pmid: 18086972
references.citation: J Clin Oncol. 2001 Jul 1;19(13):3234-43
references.pmid: 11432891
references.citation: J Clin Oncol. 2011 Jun 10;29(17):2312-8
references.pmid: 21555682
references.citation: Nat Clin Pract Oncol. 2009 Mar;6(3):132-3
references.pmid: 19190590
references.citation: J Clin Oncol. 2010 Oct 1;28(28):4390-9
references.pmid: 20697078
references.citation: Nat Clin Pract Oncol. 2007 Dec;4(12):690-1
references.pmid: 17909551
references.citation: J Clin Oncol. 2011 Jan 20;29(3):330-6
references.pmid: 21149657
references.citation: J Immunother. 2010 Jan;33(1):83-91
references.pmid: 19952953
references.citation: Cancer Immunol Immunother. 2011 Apr;60(4):525-35
references.pmid: 21207025
references.citation: Ann N Y Acad Sci. 2009 Dec;1182:39-46
references.pmid: 20074273
references.citation: J Immunol. 2000 Jun 1;164(11):5998-6004
references.pmid: 10820283
references.citation: N Engl J Med. 2006 Feb 9;354(6):567-78
references.pmid: 16467544
references.citation: Cancer Res. 2012 Jan 1;72(1):45-55
references.pmid: 22058147
references.citation: Semin Immunol. 2007 Feb;19(1):24-32
references.pmid: 17275323
references.citation: Lancet. 2009 May 2;373(9674):1525-31
references.pmid: 19410716