TCR signaling induces selective exclusion of CD43 from the T cell-antigen-presenting cell contact site.
CD43, a large highly glycosylated molecule, is arguably the most abundant molecule on the surface of T cells. Nevertheless, the function of CD43 remains unclear. Utilizing fluorescence microscopy, we find that CD43 is excluded from the T cell-APC contact site. This exclusion is Ag dependent since optimal CD43 exclusion requires Ag-pulsed APC, and since signaling through CD3, in the absence of any other receptor ligand interactions, can induce the modulation of CD43. These data suggest that CD43 may function as a barrier to nonspecific T cell-APC interactions that is removed as a result of T cell activation. Exclusion from the interaction site is a unique feature of CD43 and not universally found for all large highly glycosylated molecules since CD45 is not excluded. Thus, CD43 may represent a novel regulatory molecule on the T cell surface that can direct T cell interactions by changing its location on the cell surface.
Sperling
A I
AI
Department of Medicine, University of Chicago, IL 60637, USA. asperlin@medicine.bsd.uchicago.edu
Sedy
J R
JR
Manjunath
N
N
Kupfer
A
A
Ardman
B
B
Burkhardt
J K
JK
D000938:Antigen-Presenting Cells / Q000276:immunology*; D015703:Antigens, CD; D002450:Cell Communication; D002462:Cell Membrane / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis; D051917:Leukosialin; D008213:Lymphocyte Activation; D046911:Macromolecular Substances; D009038:Motion; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D012795:Sialoglycoproteins / Q000378:metabolism*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; D051917:Leukosialin; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell; C465014:SPN protein, human; D012795:Sialoglycoproteins; D017493:Leukocyte Common Antigens