T cells has unique surface receptors which interacts specifically with an antigen. Helper T cell receptor can bind only to antigenic peptide MHC class II complex on antigen presenting cells. T helper cells activate both T cells and B cells.
|T cell receptor|
- TCR is a heterodimer consisting of alpha and beta chain
- A variable region the hypervariable region determines the specificity
- A constant region
- A transmembrane region for anchorage
- And a short cytoplasmic region that interacts with cytoskeletal structures
- Each T cell bears a TCR of single specificity