CD169+ Macrophages Residing in the Draining Lymph Nodes and Infiltrating the Tumor Play Opposite Roles in the Pathogenesis of Bladder Cancer

Masakazu Nagata,1 Kazuhiro Ishizaka,1 Touko Asano1,2 1Department of Urology, Teikyo University Hospital Mizonokuchi, Kawasaki, Kanagawa, Japan; 2Department of Urology, Omori Red Cross Hospital, Ota, Tokyo, JapanCorrespondence: Touko Asano, Department of Urology, Teikyo University Hospital Mizonokuchi, 5-1-1 Futago, Takatsu, Kawasaki, Kanagawa, 213-8507, Japan, Tel +81-044-844-3333, Fax +81-044-844-3208, Email touko_bg7@hotmail.co.jpPurpose: CD169+ macrophages are considered to enhance anti-tumor immunity by capturing lymph-borne dead tumor cells. The number of CD169+ macrophages in regional lymph nodes (RLNs) is positively correlated with prolonged cancer-free survival in various human cancers. However, a recent study argued against this dogma; that is, CD169+ macrophages infiltrating into the tumor were associated with poor prognosis in patients with breast cancer. To explain this discrepancy, we quantified the number of CD169+ macrophages located in the bladder tumor and RLNs of the same patients and examined their relationship with the 5-year survival rate.Patients and Methods: Tumor and RLN specimens resected from 40 invasive bladder cancer patients (29 males and 11 females; median age, 70.7 years; range, 49– 81 years) who underwent radical cystectomy were evaluated using immunostaining.Results: The number of CD169+ macrophages in RLNs was associated with a good cancer prognosis, while CD169+ macrophages infiltrating the tumor strongly correlated with a higher incidence of lymphovascular invasion.Conclusion: CD169+ macrophages play opposing roles in the induction of anti-tumor immunity based on their location in RLNs or tumors.Keywords: anti-tumor immunity, tumor-associated macrophage, CD169