HLA class II histocompatibility antigen DR beta chain (HLA-DRB) (HLA-DRB)

HLA class II histocompatibility antigen DR beta chain (HLA-DRB) is a polymorphic transmembrane glycoprotein that forms the beta subunit of the HLA-DR heterodimer, a member of the Major Histocompatibility Complex (MHC) class II family [UniProt: P01911]. Its primary biological function is the presentation of exogenous peptides to CD4+ T-lymphocytes, a process essential for the initiation and regulation of the adaptive immune response [PubMed: 15634800]. While HLA-DR is normally expressed on professional antigen-presenting cells like B-cells and macrophages, it is significantly overexpressed on the surface of malignant B-lymphocytes in diseases such as non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) [PubMed: 11588142]. This high density on tumor cells makes HLA-DRB an attractive target for immunotherapy. Therapeutic agents like Apolizumab and Lym-1 have been developed to exploit this expression, triggering tumor cell death through antibody-dependent cellular cytotoxicity (ADCC) and the direct induction of apoptosis [PubMed: 2404545]. However, because HLA-DR is also present on healthy immune cells, treatment can lead to transient B-cell depletion and increased susceptibility to infections [PubMed: 12689931].

Other names

HLA-DR beta chainMHC class II antigen DRBMajor histocompatibility complex class II DR beta chainHLA-DRB1HLA-DRB3HLA-DRB4HLA-DRB5

Monoclonal antibodies targeting HLA-DRB induce cell death in malignant B-cells through antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and the direct induction of apoptosis via signaling pathways [PubMed: 11588142, 2404545].