Fig. 1.

Anit-CEA IgCD28TCR molecular construction and expression. A. IgCD28TCR versus IgTCR. The IgCD28TCR construct was created from IgTCR by molecular insertion of the complete CD28 transmembrane (TM) and cytoplasmic domains and a portion of the CD28 extracellular domain (ECD). Upper: schematic representation of surface expressed molecules. Lower: molecular design of colinear constructs. Note that both constructs have identical sFv-CD8α hinge and TCR.ζ cytoplasmic domains. B. IgCD28TCR expression. Transduced normal human T cells were stained with WI2 anti-MN14-idiotype Ab and analyzed by FACS. Shaded profile, untransduced control; open profile, transduced cells. Transduced fraction measured as 22%. C. Sizes of CIRs. Western blots of membrane fractions from untransduced or transduced (~40%) human T cells were detected with anti-TCRζ monoclonal antibody. Monomeric and dimeric forms of the endogenous TCRζ, IgTCR and IgCD28TCR are indicated by arrows. Other forms are interpreted as cleavage products.⁵