Alterations of T-cell functions during Friend leukemia complex infection: defective signal transduction?
Proliferative and interleukin responses to T-cell mitogens such as concanavalin A (Con A) were rapidly and progressively reduced in BALB/c mice infected with the Friend leukemia complex (FLC) or its helper, Friend murine leukemia virus (F-MuLV). In contrast, a combination of the protein kinase C activator phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and the Ca++ ionophore A23187 elicited a normal lymphoproliferative response up to 8 days postinfection (p.i.) and normal interleukin-2 (IL-2) and interferon-gamma responses up to day 14 p.i. Exogenous IL-2 failed to restore the lymphoproliferative response of infected cells regardless of the stimulation used. These results showed that the T-cell deficits may be at least partly attributable to a derangement of the signal transduction pathway leading to activation. Spleen cells passed through nylon wool columns reacquired a normal responsiveness to Con A +/- TPA up to 14 days p.i. The latter finding suggests that the alterations in signal transduction are not caused by primary defect of the responder-T cells but may result from an extrinsic suppressive mechanism.
Soldaini
E
E
Department of Biomedicine, University of Pisa, Italy.
Matteucci
D
D
Capobianchi
M R
MR
Baldinotti
F
F
Giovannetti
A
A
Dianzani
F
F
Bendinelli
M
M
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D003208:Concanavalin A / Q000494:pharmacology; D005374:Filtration; D005455:Fluorescent Antibody Technique; D005622:Friend murine leukemia virus / Q000276:immunology*; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis / Q000494:pharmacology; D007942:Leukemia, Experimental / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007376:Interleukin-2; D003208:Concanavalin A; D000001:Calcimycin; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate