T-cell receptor (TCR) on CD4+ T-cells (CD4+ TCR)

The CD4+ T-cell receptor (TCR) is a multi-subunit protein complex found on the surface of helper T-cells that is responsible for recognizing fragments of antigens (peptides) bound to Major Histocompatibility Complex (MHC) class II molecules (Source: UniProt P01848). In the context of vaccination, these receptors identify vaccine-derived peptides presented by professional antigen-presenting cells, such as dendritic cells, to initiate a protective adaptive immune response (Source: PMID: 28273103). Upon binding, the TCR signals the T-cell to release cytokines and provide help to B-cells for antibody production and to CD8+ T-cells for cytotoxic activity. This target is central to the efficacy of most prophylactic vaccines and is increasingly being harnessed in therapeutic contexts, such as TCR-engineered T-cell therapies for cancer and infectious diseases. Modulating CD4+ TCR activity is also a key strategy in treating autoimmune disorders where the receptor inappropriately recognizes self-peptides. Therapeutic agents like Teplizumab or Abatacept interact with the TCR complex or its co-signaling pathways to modify immune outcomes (Source: PubMed). Understanding the specificity and affinity of these receptors is crucial for designing next-generation vaccines and immunotherapies. The diversity of the TCR repertoire allows for the recognition of a vast array of vaccine-derived epitopes, ensuring broad population coverage.

Other names

CD4+ T-cell receptorMHC class II-restricted T-cell receptorAlpha-beta T-cell receptorTCR-CD3 complex

The CD4+ T-cell receptor recognizes peptide-MHC class II complexes on antigen-presenting cells, initiating a signaling cascade via the CD3 complex and ZAP-70 kinase that leads to T-cell activation, proliferation, and differentiation into various helper T-cell subsets (Source: PMID: 31043726).