OBJECTIVETo investigate the specific antitumor immunity induced by antigen peptide mixture prepared from different T lymphocytic leukaemia cells and the cross-reaction among the mixtures of different cell lines.

METHODSAntigen peptide mixtures were prepared from different leukaemia cell lines and then bound with Hsp70 in vitro. The activation and proliferation of peripheral blood mononuclear cell (PBMC) were observed after the stimulation by different Hsp70-peptide complexes. The cytotoxicity of such activated PBMCs to different target cells was assayed.

RESULTSThe antigen peptides from different leukaemia cell lines were mixed ones, which could activate PBMC effectively with Hsp70 and stimulate the activated PBMC to proliferate. The proliferative PBMC had specific cytotoxicity to the corresponding leukaemia cells. To Hut-78 cell, Molt-4 cell and Jurkat cell, the cytotoxicity of PBMC activated by either Hut78-peptides or Molt-4-peptides was significantly stronger than that of PBMC activated by HL-60-peptides (P < 0.05). The cytotoxicity to Jurkat cell of PBMC activated by Hut78/Molt-4-peptides was significantly stronger than that of PBMC activated by Hut78-peptides or Molt-4-peptides alone (P < 0.05).

CONCLUSIONAntigen peptide mixture from T lymphocytic leukaemia cells is able to induce specific antitumor immunity. There is a cross-reactivity among antigen peptide mixtures from different T lymphocytic leukaemia cell lines, with the more crossed antigen peptides obtained from the mixtures of different antigen peptides from different T lymphocytic leukaemia cell lines, which suggests that the antigen peptide mixture with broad antigenic spectrum could possibly be prepared by using multiple leukaemia cell lines.