Table 3 Comparison of key features of engineered TCRs versus CARs

From: Harnessing the biology of regulatory T cells to treat disease

Feature

TCR

CAR

Affinity

Low

High/variable

Co-stimulation

Exogenous

Incorporated

Sensitivity (number of antigens required on target)

High (low antigen density)

Low (high antigen density)

Specificity

Cross-reactive

High

Endogenous TCR

Prone to mispairing

Independent (typically)

Target antigens

Extracellular and intracellular

Membrane bound and oligomeric (sometimes soluble)

Antigen type

Processed peptides

Range of possible targets

Major histocompatibility complex

Dependent

Independent (typically)

Immunogenicity

Unlikely

Possible

  1. CAR, chimaeric antigen receptor; TCR, T cell receptor.