Tumor metastasis is the cause of most
cancer deaths. Although
metastases can form in multiple end organs, the liver is recognized as a highly permissive organ. Nevertheless, there is evidence for immune cell-mediated mechanisms that function to suppress liver
metastasis by certain
tumors, although the underlying mechanisms for the suppression of
metastasis remain elusive. Here, we show that
Dectin-2, a
C-type lectin receptor (CLR) family of innate receptors, is critical for the suppression of liver
metastasis of
cancer cells. We provide evidence that
Dectin-2 functions in resident macrophages in the liver, known as Kupffer cells, to mediate the uptake and clearance of
cancer cells. Interestingly, Kupffer cells are selectively endowed with Dectin-2-dependent phagocytotic activity, with neither bone marrow-derived macrophages nor alveolar macrophages showing this potential. Concordantly, subcutaneous primary
tumor growth and lung
metastasis are not affected by the absence of
Dectin-2. In addition, macrophage
C-type lectin, a CLR known to be complex with
Dectin-2, also contributes to the suppression of liver
metastasis. Collectively, these results highlight the hitherto poorly understood mechanism of Kupffer cell-mediated control of
metastasis that is mediated by the CLR innate receptor family, with implications for the development of anticancer
therapy targeting CLRs.