Hsp70 Peptides Induce TREM-1-Dependent and TREM-1-Independent Activation of Cytotoxic Lymphocytes.

The novel data show that the Hsp70 protein is a potent activator of the immune system. Using limited trypsinolisis, we have identified the epitopes of Hsp70 responsible for TREM-1-dependent and TREM-1-independent cytotoxicity. The 11aa N9 peptide (AMTKDNNLLGR) contains nine amino acids that correspond to the amino acid sequence of the known TKD peptide. Also, like TKD, this peptide does not interact with the TREM-1 receptor but activates CD94+ NK cells that kill tumor cells by secreting granzymes and inducing apoptosis. The 16aa peptide N7 (SDNQPGVLIQVYEGEK) interacts with the TREM-1 receptor and induces the activation of NK cells and cytotoxic T lymphocytes at different time points. T-lymphocytes activated by this peptide induce two alternative processes of cell death in HLA-negative tumor cells, apoptosis and necroptosis, through the interaction of the FasL lymphocyte with the Fas receptor of the tumor cell. A shortened fragment of this peptide, N7.1 (SDNQPGVL), has been identified that inhibits the interaction of TREM-1 with its ligands. This peptide has shown protective effects in the development of sepsis in mice. The results obtained can be used in antitumor and anti-inflammation therapy.