Abstract 1276: CD169-positive sinus macrophages in regional lymph nodes are associated with better survival in patients with malignant melanoma

Abstract

Abstract CD169 (sialoadhesin) is a sialic acid receptor that is expressed on the particular macrophages such as lymph node sinus macrophages. Animal studies suggested that CD169+ macrophages in lymph nodes have tumor-preventing properties, but the role of these cells in human tumors has not been clarified. Therefore, we speculated that CD169+ macrophages in regional lymph nodes (RLNs) are suggested to be essential to the anti-tumor immunity and involved in the prognosis of cancer patients. To determine the significance of CD169+ macrophages in patients with malignant melanoma (MM), we examined the expression of CD169 in paraffin-embedded tissue samples from 93 patients by immunohistochemistry and their relationship with overall survival and clinicopathological factors. A high density of CD169+ cells was significantly associated with longer overall survival in patients with MM (P = 0.001). Multivariate analysis showed that the density of CD169+ cells was an independent prognostic factor. We also found that the density of CD169+ macrophage was positively correlated with the number of CD8+ cytotoxic T cells infiltrating into tumor tissues. Furthermore, interferon (IFN)-α induced strong CD169 expression on human macrophages in vitro, and IFN-α-producing cells were indeed detected surrounding CD169+ cells in lymph node. Our data support that IFN-α-producing cells may be plasmacytoid dendritic cells (pDCs) known to produce IFN-α. These results suggest that CD169+ macrophages in RLNs are intimately involved in T-cell-mediated antitumor immunity and may be a helpful marker for assessing clinical prognosis and monitoring antitumor immunity in patients with MM. Citation Format: Yoichi Saito, Koji Ohnishi, Azusa Miyashita, Satoshi Nakahara, Yukio Fujiwara, Hasita Horlad, Takanobu Motoshima, Satoshi Fukushima, Masatoshi Jinnin, Hironobu Ihn, Motohiro Takeya, Yoshihiro Komohara. CD169-positive sinus macrophages in regional lymph nodes are associated with better survival in patients with malignant melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1276. doi:10.1158/1538-7445.AM2015-1276