CD52g glycoprotein (CD52g)

CD52g is a male reproductive tract-specific glycoform of the CD52 glycoprotein, a small glycosylphosphatidylinositol (GPI)-anchored protein [1, 4]. It is synthesized and secreted by the epithelial cells of the epididymis, vas deferens, and seminal vesicles, and is subsequently acquired by spermatozoa during their maturation process [1, 3]. While the peptide backbone of CD52g is identical to the CD52 found on lymphocytes, it possesses a unique, highly sialylated N-linked carbohydrate epitope that is absent in other tissues and in women [1, 4, 11]. This specificity makes CD52g an ideal target for non-hormonal immunocontraception [2, 9]. Monoclonal antibodies directed against CD52g, such as the Human Contraception Antibody (HCA), work by rapidly agglutinating and immobilizing sperm, effectively preventing them from traversing the cervical mucus to reach the egg [1, 8, 10]. Clinical development of topical formulations, such as vaginal films (e.g., ZB-06), has shown promise for on-demand contraception with a high safety profile due to the target's restricted expression [1, 14, 15]. Additionally, CD52g may play a role in the transmission of sexually transmitted infections, making it a potential target for multipurpose prevention technologies [4, 6, 12]. The target is universally present on human sperm, ensuring broad applicability for contraceptive interventions [3, 16].

Other names

Sperm-associated CD52S-CD52SAGA-1 antigenMale reproductive tract-specific CD52CAMPATH-1 antigen (sperm-specific glycoform)

Sperm agglutination and immobilization via binding to a unique carbohydrate epitope, leading to the trapping of sperm in cervical mucus and prevention of fertilization.