Antineoplastic effect of bacterial superantigens in a model of human acute t-lymphoblastic leukemia

DUARTE ALEJANDRA; MONTAGNA DANIELA; PASTORINI MERCEDES; RUGGIERO RAÚL; ALEMÁN MERCEDES

Congreso; Reunion anual de sociedades de biociencias; 2022

Superantigens (Sags) are bacterial and viral proteins that bind tomajor histocompatibility complex (MHC) class II molecules as unprocessedproteins and interact with T cells expressing the particularT-cell receptor (TCR) Vβ chains. We have previously describedthat Sags could induce apoptosis of neoplastic T cells in mice andeven increase the survival of mice bearing T-cell lymphomas. Herewe investigated the effect of Sag SEE (enterotoxin E from the bacteriumStaphylococcus aureus), which specifically interacts withcells expressing the Vβ8 chain, on the human neoplastic cell lineJurkat, that carries the Vβ8 chain of the TCR. Preliminary experimentsshowed that SEE SAg could induce apoptosis of Jurkat cellsby significantly reducing the tumor size and blood infiltration of neoplasticcells in the NOD/Scid mice model. In the present work, weABSTRACTS 241confirm these results, and we evaluated whether Sags were capableof improving the survival of mice carrying human neoplastic Tcells. Jurkat cells (10x106) were inoculated intravenously (i.v.), andafter two days, the mice were treated with Sag or PBS, monitoringweight and behavior every seven days. Sags-treated mice did notlose weight compared to untreated mice (SEE vs. PBS *p