Details

Autor(en) / Beteiligte

• Isler, Patrick
• Salvi, Suzanne
• Rapin, Christophe
• Giuffrè, Laura
• And, Jean‐Charles Cerottini
• Carrel, Stefan

Titel

ANTIGEN‐INDEPENDENT ACTIVATION OF T CELLS MEDIATED BY A NOVEL CELL SURFACE HETERODIMER (TPL35‐145)

Ist Teil von

• European journal of immunology, 1988-10, Vol.18 (10), p.1491-1498

Ort / Verlag

Weinheim: WILEY‐VCH Verlag GmbH

Erscheinungsjahr

1988

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• A new heterodimeric structure, Tp135‐145, which can mediate interleukin 2 (IL2) production and Ca2+ mobilization by Jurkat cells is described. This structure was identified by a monoclonal antibody, MX24, on the surface of either T3/TcR+ or T3/TcR− human T cell lines as well as on B cell lines. Biochemical studies showed that antibody MX24 precipitated two polypeptide chains of 135 and 145 kDa, respectively, in lysates from 125I‐labeled T cells. After reduction the 135‐kDa polypeptide chain shifted to 140 kDa, whereas the molecular mass of the other polypeptide remained unchanged. The apparent molecular masses of the desialylated polypeptides differed by 5 kDa. No common peptide fragments between the two polypeptide chains were found after limited proteolysis by Staphylococcus aureus V8 protease. The expression of Tp135‐145 was independent of the expression of the T3/TcR molecular complex. Incubation of Jurkat cells with anti‐TcR or anti‐T3 monoclonal antibody induced complete modulation only of the T3/TcR complex but not of Tp135‐145. Conversely complete modulation of Tp135‐145 was observed after incubation of these cells with MX24 antibody. Functional studies showed that anti‐Tp135‐145 antibody MX24 induced high levels of IL2 production in Jurkat cells. In addition, incubation of these cells with MX24 resulted in Ca2+ mobilization from internal stores. In peripheral blood, Tp135‐145 was found to be expressed by 39%‐76% of resting T cells in individual donors. Two‐color flow microfluorimetry showed that the Tp135‐145′ cells were equally distributed on the CD4+ and CD8+ subsets. Incubation of peripheral blood T cells with antibody MX24 resulted in IL 2 production and cell proliferation. Taken together these results suggest that Tp135‐145 is a novel surface molecule involved in antigen‐independent pathway of T cell activation.