SLAM family member 5 (CD84) (CD84)

SLAM family member 5 (CD84) is a cell surface receptor belonging to the Signaling Lymphocyte Activation Molecule (SLAM) family, functioning primarily as a homophilic adhesion molecule [1, 11]. It is widely expressed across the hematopoietic lineage, including B cells, T cells, monocytes, and platelets, where it regulates immune cell activation, communication, and germinal center formation [1, 6]. In hematologic malignancies such as Chronic Lymphocytic Leukemia (CLL) and Multiple Myeloma (MM), CD84 is significantly upregulated and serves as a critical survival receptor [5, 15]. It mediates interactions between malignant cells and their microenvironment, triggering pro-survival signaling through the AKT and MAPK pathways and inducing the expression of anti-apoptotic proteins like Bcl-2 [15, 29]. Additionally, CD84 plays a role in immune evasion by upregulating the PD-L1 checkpoint and promoting the expansion of myeloid-derived suppressor cells (MDSCs) [3, 12]. In Acute Myeloid Leukemia (AML), CD84 has been shown to promote DNA repair via the non-homologous end joining (NHEJ) pathway, further contributing to chemoresistance [4, 9]. Therapeutic targeting of CD84, using monoclonal antibodies like SLM124 or CAR T-cell therapies, aims to disrupt these survival signals and restore anti-tumor immune responses [22, 33].

Other names

SLAMF5LY9BhmCD84Hly9-betaCell surface antigen MAX.3Leukocyte differentiation antigen CD84Signaling lymphocytic activation molecule 5

Inhibition of homophilic CD84-CD84 interactions to disrupt survival signaling (AKT/MAPK), reduce immunosuppression (PD-L1 downregulation), and inhibit DNA repair (NHEJ).