Expression of a functional CD3-Ti antigen/MHC receptor in the absence of surface CD2. Analysis with clonal Jurkat cell mutants.
To investigate the requirement for CD2 expression in activation of T lymphocytes via the CD3-Ti antigen/MHC receptor complex, we produced and characterized a series of CD2- Jurkat variants. These mutants lack detectable surface CD2 as determined by indirect immunofluorescence, immunoprecipitation analysis, and specific radiolabeled antibody binding assay, but nevertheless, expressed normal numbers of CD3-Ti receptors. As expected, the combination of anti-CD2 antibodies, termed anti-T112 and anti-T113, which are mitogenic for resting T lymphocytes, failed to stimulate activation of these variants. In contrast, triggering of their CD3-Ti components resulted in the normal set of T lymphocyte-associated activation events, including phosphoinositide turnover, elevation in intracellular free calcium, early gene-induction events, and IL-2 production. Assuming that the Jurkat cell line is representative of normal cycling human T lymphocytes, we conclude that the presence of the CD2 molecule on the plasma membrane is not in itself a requirement for an operational CD3-Ti-alpha/beta receptor.
Moingeon
P
P
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Alcover
A
A
Clayton
L K
LK
Chang
H C
HC
Transy
C
C
Reinherz
E L
EL
D000945:Antigens, Differentiation, T-Lymphocyte; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D008213:Lymphocyte Activation; D009154:Mutation; D010716:Phosphatidylinositols / Q000378:metabolism; D014176:Protein Biosynthesis; D011948:Receptors, Antigen, T-Cell; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D000945:Antigens, Differentiation, T-Lymphocyte; D010716:Phosphatidylinositols; D011948:Receptors, Antigen, T-Cell; D002118:Calcium