Signal requirements for activation of leukaemic T cells from a chronic lymphocytic leukaemia (T-CLL).
In order to define the signal requirements for leukaemic T cell activation, the proliferation and interleukin-2 (IL-2) production of peripheral lymphocytes from a patient with a HTLV-I-, CD4+, CD45RA+ CD45RO+ CD25- T-CLL were evaluated after the delivery of different stimuli. Unlike resting CD4+ normal T lymphocytes that can be activated only by a two-signal stimulation, T-CLL cells proliferated and released IL-2 in response to a pair of anti-CD2 monoclonal antibodies (MoAbs) or concanavalin A (Con A) in the absence of both accessory cells (AC) and phorbol myristate acetate (PMA). The two stimuli were also able to induce CD25 expression within 12-20 h on the majority of T-CLL cells. A response to anti-CD3 and anti-CD28 MoAbs was detected only in the presence of PMA, similar to that observed in normal resting T lymphocytes matched for phenotype. Both Con A- and CD2-induced proliferation were strongly inhibited by the addition of anti-CD25 MoAb. Furthermore, T-CLL lymphocytes acquired anti-tumour lytic activity after culture in the presence of PMA and ionomycin. We conclude that HTLV1- CD25- T-CLL can be characterized not only by morphological and phenotypical studies but also on the basis of signal requirements for cell activation.
Zocchi
M R
MR
Istituto Scientifico San Raffaele, Milan, Italy.
Poggi
A
A
Heltai
S
S
Villa
A
A
Inverardi
L
L
Vicari
A
A
Sabbadini
M G
MG
Ferrarini
M
M
D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D018801:CD2 Antigens; D018106:CD28 Antigens; D017252:CD3 Complex; D003208:Concanavalin A; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D018106:CD28 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A; D013755:Tetradecanoylphorbol Acetate