RESUMO
BACKGROUND AIMS: The impact of chronic lymphatic leukemia (CLL) tumor burden on the autologous immune system has already been demonstrated. This study attempted to elucidate the molecular mechanisms underlying T-cell immunologic deficiencies in CLL. METHODS: Freshly isolated CD3(+) T cells from patients with a diagnosis of CLL and healthy donors were analyzed by gene expression profiling. Activated T cells from 20 patients with CLL were tested in vitro for cytotoxicity against mutated and unmutated autologous B cells and DAUDI, K562 and P815 cell lines. To investigate T-cell mediated cytotoxicity in vivo, we co-transplanted OKT3-activated T lymphocytes and autologous B-cell CLL (B-CLL) cells into NOD/SCID mice. RESULTS: Gene expression profiles of peripheral blood T cells from B-CLL patients showed 25 down-regulated, and 31 up-regulated, genes that were mainly involved in cell differentiation, proliferation, survival, apoptosis, cytoskeleton formation, vesicle trafficking and T-cell activation. After culture, the T-cell count remained unchanged, CD8 cells expanded more than CD4 and a cytotoxicity index >30% was present in 5/20 patients. Cytotoxicity against B autologous leukemic cells did not correlate with B-cell mutational status. Only activated T cells exerting cytotoxicity against autologous leukemic B cells prevented CLL in a human-mouse chimera. CONCLUSIONS: This study indicates that patients with CLL are affected by a partial immunologic defect that might be somewhat susceptible to repair. This study identifies the molecular pathways underlying T-cell deficiencies in CLL and shows that cytotoxic T-cell functions against autologous B-CLL can be rebuilt at least in part in vitro and in vivo.
Assuntos
Citotoxicidade Imunológica/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/imunologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/genética , Regulação para Baixo/genética , Regulação para Baixo/fisiologia , Perfilação da Expressão Gênica , Rearranjo Gênico do Linfócito B/genética , Rearranjo Gênico do Linfócito B/imunologia , Humanos , Fatores Imunológicos/farmacologia , Interleucina-2/farmacologia , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/genética , Ativação Linfocitária/fisiologia , Camundongos , Camundongos SCID , Muromonab-CD3/farmacologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Hipermutação Somática de Imunoglobulina/genética , Hipermutação Somática de Imunoglobulina/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Regulação para Cima/genética , Regulação para Cima/fisiologiaRESUMO
Although adoptive transfer of donor lymphocytes protects from infections and relapse after allogeneic hematopoietic stem cell transplantation in both mice and in men, it is associated with a high risk of graft versus host disease (GvHD) which rises with HLA mismatching and the number of T lymphocytes that are infused. Elimination/reduction of alloreactive donor T lymphocytes is an appealing approach and several strategies have been proposed. Here we describe generation of anti-3rd party T lymphocytes under conditions of IL-2 deprivation and their effects in a pre-clinical murine model. Our results clearly indicated that anti-3rd party T lymphocytes generated on a large scale by means of IL-2 deprivation maintain a broad T cell repertoire, do not proliferate in a mixed lymphocyte reaction and do not cause GvHD in NOD-SCID mice. These anti-3rd party lymphocytes contain a large adaptive T regulatory cell subset which might contribute to in vitro and in vivo immune modulation.