IFNbeta produced by TLR4-activated tumor cells is involved in improving the antitumoral immune response

NICOLAS NUÑEZ; VIRGINIA ANDREANI; MARÍA INÉS CRESPO; MARÍA LAURA BRESER; GABRIEL MORÓN; LIEN DEJAGER; CLAUDE LIBERT; VIRGINIA RIVERO; MARIANA MACCIONI

AMER ASSOC CANCER RESEARCH

Año: 2012 vol. 72 p. 592 - 592

Toll-like receptor (TLR) ligands may be a valuable tool to promote antitumor responses by reinforcing antitumor immunity. In addition to their expression in immune cells, functional TLRs are also expressed by many cancer cells, but their significance has been controversial. In this study, we examined the action of TLR ligands on tumor pathophysiology as a result of direct tumor cell effects. B16 murine melanoma cells were stimulated in vitro with a TLR4 ligand (LPS-B16) prior to inoculation into TLR4-deficient mice (Tlr4 lps-del). Under such conditions, B16 cells yielded smaller tumors than nonstimulated B16 cells. The apoptosis/proliferation balance of the cells was not modified by TLR ligand treatment, nor was this effect compromised in immunocompromised nude mice. Mechanistic investigations revealed that IFNb was the critical factor produced by TLR4-activated tumor cells in mediating their in vivo outgrowth. Transcriptional analysis showed that TLR4 activation on B16 c