Idiotype peptide-Major Histocompatibility Complex class II complex (Id-MHCII)

The Idiotype peptide presented on MHC class II (Id-MHCII) complex is a highly specific tumor neoantigen found on the surface of malignant B-cells, such as those in Follicular Lymphoma and Multiple Myeloma. These malignant cells express a unique, clonal B-cell receptor (BCR) whose variable regions contain distinct amino acid sequences known as idiotypes. Through the endogenous processing pathway, these idiotype proteins are internalized, degraded into peptides, and subsequently loaded onto MHC class II molecules for presentation to the immune system. This complex is a primary target for personalized immunotherapy because the specific idiotype is unique to the tumor clone and absent from healthy B-cells. Therapeutic strategies often involve idiotype-pulsed dendritic cells or personalized vaccines designed to elicit a CD4+ T-cell-mediated immune response that specifically recognizes the Id-MHCII complex to induce tumor cell death.

Other names

Id-peptide/MHCII complexTumor-specific idiotype antigenB-cell receptor-derived peptide presented on MHC class IIClonal idiotype-MHC II complex

Activation of CD4+ T-helper cells through the recognition of unique variable region peptides (idiotypes) presented on MHC class II molecules, leading to anti-tumor immune responses and direct or indirect elimination of malignant B-cells.