T cell costimulation by the TNF ligand BAFF.
The TNF ligand family member BAFF (B cell activating factor belonging to the TNF family, also called Blys, TALL-1, zTNF-4, or THANK) is an important survival factor for B cells [corrected]. In this study, we show that BAFF is able to regulate T cell activation. rBAFF induced responses (thymidine incorporation and cytokine secretion) of T cells, suboptimally stimulated through their TCR. BAFF activity was observed on naive, as well as on effector/memory T cells (both CD4+ and CD8+ subsets), indicating that BAFF has a wide function on T cell responses. Analysis of the signal transduced by BAFF into T cells shows that BAFF has no obvious effect on T cell survival upon activation, but is able to deliver a complete costimulation signal into T cells. Indeed, BAFF is sufficient to induce IL-2 secretion and T cell division, when added to an anti-TCR stimulation. This highlights some differences in the BAFF signaling pathway in T and B cells. In conclusion, our results indicate that BAFF may play a role in the development of T cell responses, in addition to its role in B cell homeostasis.
Huard
B
B
Department of Dermatology, Geneva University Medical Center, Geneva, Switzerland. huard@cmu.unige.ch
Schneider
P
P
Mauri
D
D
Tschopp
J
J
French
L E
LE
D053264:B-Cell Activating Factor; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D007376:Interleukin-2 / Q000502:physiology; D007399:Interphase / Q000276:immunology; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology*; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000502:physiology*
D053264:B-Cell Activating Factor; D016207:Cytokines; D007376:Interleukin-2; D008024:Ligands; D008565:Membrane Proteins; D011948:Receptors, Antigen, T-Cell; D018124:Receptors, Tumor Necrosis Factor; C505719:TNFSF13B protein, human; D014409:Tumor Necrosis Factor-alpha; D013936:Thymidine