Functional consequences of the interaction between T-cell antigen receptors and Fc gamma Rs on T cells.
Two series of experiments are presented indicating that Fc gamma II receptors can interfere with the antigen receptor-induced signaling on T cells. It has been previously described that a 13 amino acid motif on the cytoplasmic portion of Fc gamma II beta 1 can abrogate the antigen receptor-initiated signals mediated through consensus motifs present on the cytoplasmic portion of Ig alpha and Ig beta chains. Similar activating motifs are crucial to T-cell receptor (TCR) signaling. A splenic gamma/delta T-cell hybridoma that expressed the Fc gamma RII beta 1 receptor helped to establish that this receptor can also interfere with TCR-induced activation. The cytoplasmic portion of human Fc gamma RIIa has an activation motif similar to the activation motifs present on the TCR. Using a transgenic mouse in which the T cells express the human Fc gamma RIIa transgene, we demonstrated that despite the common activation motif, the TCR and human Fc gamma RIIa-induced signals are different. Additionally, the human Fc gamma RIIa expressing T cells exhibit an enhanced TCR response both in vitro and in vivo.
Kwack
K
K
Department of Pathology College of Medicine, University of Iowa, Iowa City, USA.
Verbeek
J S
JS
van de Winkel
J G
JG
Cappel
P
P
Nambu
M
M
Hagen
M
M
Weinstock
J V
JV
Lynch
R G
RG
Sandor
M
M
D015703:Antigens, CD; D006801:Humans; D018448:Models, Immunological; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D017452:Receptors, IgG / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; C080571:Fc gamma receptor IIB; D011948:Receptors, Antigen, T-Cell; D017452:Receptors, IgG; D011994:Recombinant Proteins