SUPERANTIGEN INDUCE EXTRINSIC AND INTRINSIC APOPTOSIS PATHWAY IN HUMAN NEOPLASTIC T CELLS

PIAZZON ISABEL; ALEMÁN MERCEDES; AGUSTÍN VITTI; ALEJANDRA DUARTE

buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Superantigens (Sags) are bacterial and virus protein that sharethe ability to activate large number of T-cells. Sags bind to majorhistocompatibility complex (MHC) class II molecules as unprocessedproteins and interact with T cells expressing particular T-cellreceptor (TCR) Vβ chains. Sags activated T-cells after severalrounds of proliferation. We previously demonstrated that T-cell Sagsinduced apoptosis of cognate malignant T cells. We have shownthat both bacterial- and mouse mammary tumour virus (MMTV)-encodedSags induce apoptosis of different murine-cognate lymphomaT cells in vitro and in vivo, being the Fas/Fas-L pathway involved.In vivo exposure to bacterial T Sags increased the survivalof lymphoma-bearing mice. We also observed that Sags induceapoptosis in cells of the Jurkat-established human cell line from anacute T-carrier leukemia of the Vβ8 region in TCR. We proposedto analyze those mechanisms involved in apoptosis of Jurkat cellsinduced by Sag. We co-cultivated Jurkat cells with THP1 cell line(as antigen presenting cells). Then we treated them with or withoutdifferent Sags (specific or not for the TCR Vβ chain) at different timepoints. We observed an increase in Fas-L expression analyzed byPCR and flow cytometer (p