RESUMO
Nucleophosmin1 (NPM1) is one of the most commonly mutated genes in AML and is often associated with a favourable prognosis. Immune responses play an increasing role in AML treatment decisions; however, the role of immune checkpoint inhibition is still not clear. To address this, we investigated specific immune responses against NPM1, and three other leukaemia-associated antigens (LAA), PRAME, Wilms' tumour 1 and RHAMM in AML patients. We investigated T cell responses against leukaemic progenitor/stem cells (LPC/LSC) using colony-forming immunoassays and flow cytometry. We examined whether immune checkpoint inhibition with the anti-programmed death 1 antibody increases the immune response against stem cell-like cells, comparing cells from NPM1 mutated and NPM1 wild-type AML patients. We found that the anti-PD-1 antibody, nivolumab, increases LAA stimulated cytotoxic T lymphocytes and the cytotoxic effect against LPC/LSC. The effect was strongest against NPM1mut cells when the immunogenic epitope was derived from the mutated region of NPM1 and these effects were enhanced through the addition of anti-PD-1. The data suggest that patients with NPM1 mutated AML could be treated with the immune checkpoint inhibitor anti-PD-1 and that this treatment combined with NPM1-mutation specific directed immunotherapy could be even more effective for this unique group of patients.
Assuntos
Inibidores de Checkpoint Imunológico , Leucemia Mieloide Aguda , Nucleofosmina , Linfócitos T Citotóxicos , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunidade , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Mutação , Nivolumabe/farmacologia , Nucleofosmina/genética , Receptor de Morte Celular Programada 1/antagonistas & inibidoresAssuntos
Imunidade Celular , Leucemia Linfocítica Crônica de Células B/imunologia , Linfócitos T Reguladores/imunologia , Idoso , Idoso de 80 Anos ou mais , Vacinas Anticâncer , Estudos de Casos e Controles , Feminino , Humanos , Interleucina-2/farmacologia , Leucemia Linfocítica Crônica de Células B/terapia , Masculino , Pessoa de Meia-Idade , Linfócitos T Citotóxicos/imunologia , Talidomida/farmacologia , Vacinação , Vacinas de Subunidades AntigênicasRESUMO
Peptide vaccination constitutes a novel immunotherapeutical approach for the treatment of patients with solid tumors, lymphoma and leukemia. Moreover it might be of use in hematooncological patients for the prevention and therapy of infections like cytomegalovirus (CMV) reactivation due to immunosuppression. To meet good manufacturing practice (GMP) criteria, we introduce here a bio-assay to validate peptide vaccines for peptide content and bio-activity. As a paradigm for peptide vaccine preparation the immunogenic CMV peptide 495-503 NLVPMVATV lyophilisate was resolubilized in dimethyl sulfoxide, phosphate buffered saline and admixed with Montanide. Addition of different amounts of peptide (10-80 microg) to a mixed lymphocyte peptide culture (MLPC) resulted in the generation of interferon (IFN) gamma and granzyme B releasing CD8(+) CMV tetramer(+) T cells in a dose dependent manner. The combination of FACS and ELISPOT results allowed the definition of the peptide amount in a vaccine preparation. Storage at +/-4 degrees C over 24 h did not result in a significant change of the immunogenicity of the vaccine. In contrast, cryopreservation of the vaccine at -20 degrees C resulted in a loss of immunogenicity. Quantitation of tumor/viral antigen peptides admixed with adjuvants, such as incomplete Freund's adjuvant (IFA), is feasible through bio-assays as the modified ELISPOT/FACS assay described here, meeting GMP criteria for multi-center trials.
