Morphological features of cloned lymphocytes expressing gamma/delta T cell receptors.
We have analyzed the morphological characteristics of human T lymphocytes bearing CD3-associated T cell receptor (TcR) gamma and delta chains. BB3 and delta-TCS1 monoclonal antibodies (mAb) were used to identify two distinct, nonoverlapping populations of TcR gamma/delta + cells which express the products of V delta 2 and V delta 1 gene segments, respectively. In the peripheral blood, most V delta 1+ (delta TCS-1+) lymphocytes express the non-disulfide-linked form of receptor whereas V delta 2+ (BB3+) cells express the disulfide-linked form. The majority of cloned TcR gamma/delta + cells exhibit a growth pattern different from that of conventional TcR alpha/beta + cells as they adhere promptly to surfaces and undergo morphological changes which can be summarized as follows: cells spread on the surface, form a distinct uropod and, in the final phase of adherence, emit long filopodia ending with adhesion plaques. Immunofluorescence studies of TcR gamma/delta + clones demonstrated the presence of submembraneous actin microfilaments and actin-binding protein confirming that these cells are capable of active motility which is related to the propensity of TcR gamma/delta + cells to home to epithelia. Scanning electron microscope analyses of effector/target cell conjugates showed that in TcR gamma/delta + cells the region of the uropodia next to the cell body is responsible for the binding to tumor target cells. Interestingly, immunofluorescence analyses revealed that LFA-1 molecules are predominantly distributed in the uropodium whereas they are virtually absent in the cell bodies. These morphological characteristics of TcR gamma/delta + cells may pertain to defensive mechanisms the mucosal level.
Arancia
G
G
Laboratorio Ultrastrutture, Istituto Superiore di Sanita, Roma, Italy.
Malorni
W
W
Iosi
F
F
Zarcone
D
D
Cerruti
G
G
Favre
A
A
Zeromski
J
J
Grossi
C E
CE
Moretta
A
A
D000185:Actinin / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D002448:Cell Adhesion; D002455:Cell Division; D002999:Clone Cells; D003599:Cytoskeleton / Q000648:ultrastructure; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D011948:Receptors, Antigen, T-Cell / Q000145:classification*; D016176:T-Lymphocyte Subsets / Q000166:cytology*
D000199:Actins; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell; D000185:Actinin