Research progress on CD169-positive macrophages in tumors

CD169/Siglec1/sialoadhesin, a sialic acid-binding immunoglobulin-like lectin, is mainly expressed in metallophilic macrophages in the marginal zone of the spleen and in macrophages in the subcapsular sinus and medulla of lymph nodes. In addition to participating in anti-infectious immunity, recent studies have demonstrated that CD169⁺ macrophages are involved in tumor immunity and are associated with a favorable prognosis. The roles of CD169⁺ macrophages in tumors and the mechanisms of CD169⁺ macrophages and CD169 molecules involved in the tumor microenvironment and tumor immunity are described in this review.