The generation of alloreactive cytotoxic T lymphocytes requires the expression of ecto-5'nucleotidase activity.
Ecto-5'-nucleotidase (ecto-5'NT) activity is highly expressed by CTL precursor cells. The aim of this work was to investigate whether ecto-5'NT is involved in their functional activation. The inhibition of ecto-5'NT activity by biochemical (alpha,beta-methyleneadenosine 5-diphosphate; AOPCP) or immunologic inhibitors (polyclonal anti-ecto-5'NT serum) suppressed the proliferative and cytotoxic activation of CTL against a lymphoblastic B cell line in primary one-way MLC. The kinetic analysis of suppression showed that AOPCP and anti-5'NT serum had different effects: AOPCP suppressed only the activation of the cytotoxic program whereas anti-5'NT serum suppressed also recognition and binding to the stimulatory/target cell. Inhibition of CTL generation was not a metabolic consequence of the purine salvage blockade. Incubation of AOPCP-treated MLC with hypoxanthine restored proliferation but not cytotoxicity. The ecto-5'NT inhibitors used had no general toxic effect on cell numbers or viability. AOPCP selectively affected CTL generation and displayed no activity against mitogen-induced proliferation, activation of Ts cells, and generation of IL-2-activated killer cells. These data indicate that ecto-5'NT has a critical role in the functional activation of alloreactive CTL.
Massaia
M
M
Dipartimento di Medicina ed Oncologia Sperimentale, Università di Torino, Italia.
Pileri
A
A
Boccadoro
M
M
Bianchi
A
A
Palumbo
A
A
Dianzani
U
U
D015720:5'-Nucleotidase; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000494:pharmacology; D007106:Immune Sera / Q000494:pharmacology; D007113:Immunity, Innate; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects; D009708:Nucleotidases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D013234:Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology
D007042:Hypoxanthines; D007106:Immune Sera; D007166:Immunosuppressive Agents; C523965:alpha,beta-methyleneadenosine 5'-diphosphate; D019271:Hypoxanthine; D000244:Adenosine Diphosphate; D009708:Nucleotidases; D015720:5'-Nucleotidase