CD48

CD48 Full Name

CD48 antigen

CD48 Introduction

CD48 is a cell surface protein belonging to the immunoglobulin superfamily. Structurally, it is unique because it lacks a transmembrane domain; instead, it is attached to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor. CD48 is widely expressed across the hematopoietic system, found on the surface of almost all leukocytes—including T cells, B cells, Natural Killer (NK) cells, monocytes, and macrophages—but is notably absent from platelets and neutrophils in humans. This broad expression makes it a critical marker for identifying lymphoid and myeloid lineages.

Figure 1. Strcuture of CD48 antigen.

Signaling Mechanism and Lipid Rafts
Because CD48 is GPI-anchored and lacks an intracellular tail to transmit signals directly, it relies on specialized membrane microdomains known as lipid rafts. When CD48 is cross-linked by its ligands (CD2 or 2B4), it clusters within these rafts and recruits Src-family kinases, such as Lck. This clustering initiates a phosphorylation cascade that results in cellular activation, proliferation, or cytoskeletal rearrangement. In the context of the immunological synapse, CD48 accumulation helps organize the molecular machinery required for a T cell to recognize an antigen and mount an attack.

Clinical Significance and Therapeutic Potential
Given its central role as a nexus for multiple receptor-ligand interactions, CD48 is an attractive target for immunomodulation. In transplantation, blocking the CD48-CD2 interaction has been explored as a strategy to inhibit T cell co-stimulation and prevent graft rejection. In oncology, its broad expression on hematologic malignancies makes it a potential target for antibody-based therapies. Bispecific antibodies or chimeric antigen receptor (CAR) designs targeting CD48 could redirect immune effector cells against leukemia or lymphoma cells. Additionally, understanding its role as a bacterial and viral receptor opens avenues for developing anti-adhesive therapies or vaccines aimed at blocking pathogen attachment.

Alternate Names for CD48

CD48; CD48 antigen; BCM1; BLAST; Bcm-1; BLAST1; SLAMF2; Sgp-60; BLAST-1; MEM-102; AI449234; AW610730; HM48-1; BCM1 surface antigen; SLAM family member 2; MRC OX-45 surface antigen; signaling lymphocytic activation molecule 2;