1. Academic Validation
  2. Tag7 (PGLYRP1) in Complex with Hsp70 Induces Alternative Cytotoxic Processes in Tumor Cells via TNFR1 Receptor

Tag7 (PGLYRP1) in Complex with Hsp70 Induces Alternative Cytotoxic Processes in Tumor Cells via TNFR1 Receptor

  • J Biol Chem. 2015 Aug 28;290(35):21724-31. doi: 10.1074/jbc.M115.639732.
Denis V Yashin 1 Olga K Ivanova 1 Natalia V Soshnikova 1 Anton A Sheludchenkov 1 Elena A Romanova 1 Elena A Dukhanina 2 Alexander G Tonevitsky 3 Nikolai V Gnuchev 1 Alexander G Gabibov 4 Georgii P Georgiev 1 Lidia P Sashchenko 5
Affiliations

Affiliations

  • 1 From the Institute of Gene Biology, Russian Academy of Sciences (RAS), Vavilova 34/5, Moscow 119334.
  • 2 From the Institute of Gene Biology, Russian Academy of Sciences (RAS), Vavilova 34/5, Moscow 119334, the Engelhardt Institute of Molecular Biology, RAS, Moscow 119334.
  • 3 the P.A. Hertsen Moscow Research Oncology Institute, 2nd Botkinskii p. 3, Moscow 125284, and.
  • 4 From the Institute of Gene Biology, Russian Academy of Sciences (RAS), Vavilova 34/5, Moscow 119334, the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Mikluho-Maklaya 16/10, Moscow 117997, Russia.
  • 5 From the Institute of Gene Biology, Russian Academy of Sciences (RAS), Vavilova 34/5, Moscow 119334, sashchenko@genebiology.ru.
Abstract

Tag7 (also known as peptidoglycan recognition protein PGRP-S, PGLYRP1), an innate immunity protein, interacts with HSP70 to form a stable Tag7-Hsp70 complex with cytotoxic activity against some tumor cell lines. In this study, we have analyzed the programmed cell death mechanisms that are induced when cells interact with the Tag7-Hsp70 complex, which was previously shown to be released by human lymphocytes and is cytotoxic to Cancer cells. We show that this complex induces both apoptotic and necroptotic processes in the cells. Apoptosis follows the classic Caspase-8 and Caspase-3 activation pathway. Inhibition of Apoptosis leads to a switch to the RIP1-dependent Necroptosis. Both of these cytotoxic processes are initiated by the involvement of TNFR1, a receptor for TNF-α. Our results suggest that the Tag7-Hsp70 complex is a novel ligand for this receptor. One of its components, the innate immunity protein Tag7, can bind to the TNFR1 receptor, thereby inhibiting the cytotoxic actions of the Tag7-Hsp70 complex and TNF-α, an acquired immunity cytokine.

Keywords

Hsp70; RNA interference (RNAi); TNFR1; Tag7; Tag7-Hsp70 complex; apoptosis; cell death; cytotoxicity; heat shock protein (HSP); necroptosis; tumor necrosis factor (TNF).

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