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1.
Pulmonology ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38614857

RESUMO

INTRODUCTION AND OBJECTIVES: Adjuvant platinum-based chemotherapy for completely resected non-small cell lung cancer is associated with modest improvement in survival; nevertheless, no validated biomarker exists for predicting the benefit or harm of adjuvant platinum-based chemotherapy. MATERIALS AND METHODS: We simultaneously measured 27 cytokines in operative tumor specimens from a discovery cohort (n = 97) by multiplex immunoassay; half of the patients received adjuvant platinum-based chemotherapy, and the other half were observed. We tested possible prognostic and predictive factors in multivariate Cox models for overall survival (OS) and relapse-free survival (RFS), and a tree-based method was applied to detect predictive factors with respect to RFS. The results were validated in an independent validation cohort (n = 93). RESULTS: Fifty-two of 97 (54 %) patients in the discovery cohort and 50 of 93 (54 %) in the validation cohort received adjuvant chemotherapy; forty-four (85 %) patients in the discovery cohort and 37 (74 %) in the validation cohort received four cycles as planned. In patients with low IL-1ß-expressing tumors, RFS and OS were worse after adjuvant chemotherapy than after observation. The limited effect of adjuvant chemotherapy for patients with low IL-1ß-expressing tumors was confirmed in the validation cohort. Additionally, RFS and OS were prolonged by adjuvant chemotherapy only in patients with high IL-1ß-expressing tumors in the validation cohort. CONCLUSIONS: This study identified and validated low tumor IL-1ß expression as a potential biomarker of a limited response to adjuvant platinum-based chemotherapy after complete resection of pulmonary adenocarcinoma. This finding has the potential to inform adjuvant treatment decisions.

2.
Carcinogenesis ; 41(7): 984-992, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-31637423

RESUMO

Immunotherapy by blockade of the PD-1/PD-L1 checkpoint demonstrated amazing tumor response in advanced cancer patients including head and neck squamous cell carcinoma (HNSCC). However, the majority of HNSCC patients still show little improvement or even hyperprogression. Irradiation is currently investigated as synergistic treatment modality to immunotherapy as it increases the number of T-cells thereby enhancing efficacy of immunotherapy. Apart from this immunogenic context a growing amount of data indicates that PD-L1 also plays an intrinsic role in cancer cells by regulating different cellular functions like cell proliferation or migration. Here, we demonstrate opposing membrane localization of PD-L1 in vital and apoptotic cell populations of radioresistant (RR) and radiosensitive (RS) HNSCC cell lines up to 72 h after irradiation using flow cytometry. Moreover, strong PD-L1 expression was found in nuclear and cytoplasmic cell fractions of RR. After irradiation PD-L1 decreased in nuclear fractions and increased in cytoplasmic fractions of RR cells. In contrast, RS cell lines did not express PD-L1, neither in the nucleus nor in cytoplasmic fractions. Additionally, overexpression of PD-L1 in RS cells led to a proportional increase of vital PD-L1 positive cells after irradiation. Moreover, co-immunoprecipitation experiments revealed an interaction between Akt-1 and PD-L1, mostly in irradiated RR cells compared to RS cells suggesting a differential influence of PD-L1 on cell signaling. In summary, our data imply the need for different therapeutic strategies dependent on the molecular context in which PD-L1 is embedded.


Assuntos
Antígeno B7-H1/genética , Proteínas Proto-Oncogênicas c-akt/genética , Tolerância a Radiação/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , Apoptose , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linhagem Celular Tumoral , Proliferação de Células , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Imunoterapia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Linfócitos T/imunologia
3.
Eur J Cancer ; 90: 122-129, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29306769

RESUMO

BACKGROUND: Immune checkpoint therapy has dramatically changed treatment options in patients with metastatic melanoma. However, a relevant part of patients still does not respond to treatment. Data regarding the prognostic or predictive significance of preexisting immune responses against tumour antigens are conflicting. Retrospective data suggested a higher clinical benefit of ipilimumab in melanoma patients with preexisting NY-ESO-1-specific immunity. PATIENTS AND METHODS: Twenty-five patients with previously untreated or treated metastatic melanoma and preexisting humoural immune response against NY-ESO-1 received ipilimumab at a dose of 10 mg/kg in week 1, 4, 7, 10 followed by 3-month maintenance treatment for a maximum of 48 weeks. Primary endpoint was the disease control rate (irCR, irPR or irSD) according to immune-related response criteria (irRC). Secondary endpoints included the disease control rate according to RECIST criteria, progression-free survival and overall survival (OS). Humoural and cellular immune responses against NY-ESO-1 were analysed from blood samples. RESULTS: Disease control rate according to irRC was 52%, irPR was observed in 36% of patients. Progression-free survival according to irRC was 7.8 months, according to RECIST criteria it was 2.9 months. Median OS was 22.7 months; the corresponding 1-year survival rate was 66.8%. Treatment-related grade 3 AEs occurred in 36% with no grade 4-5 AEs. No clear association was found between the presence of NY-ESO-1-specific cellular or humoural immune responses and clinical activity. CONCLUSION: Ipilimumab demonstrated clinically relevant activity within this biomarker-defined population. NY-ESO-1 positivity, as a surrogate for a preexisting immune response against tumour antigens, might help identifying patients with a superior outcome from immune checkpoint blockade. CLINICAL TRIAL INFORMATION: NCT01216696.


Assuntos
Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Ipilimumab/uso terapêutico , Melanoma/tratamento farmacológico , Melanoma/imunologia , Proteínas de Membrana/imunologia , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Imunidade Humoral , Masculino , Melanoma/mortalidade , Pessoa de Meia-Idade , Neoplasias Cutâneas/mortalidade , Melanoma Maligno Cutâneo
4.
Clin Exp Immunol ; 180(3): 467-74, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25644608

RESUMO

In recent years, percutaneous radiofrequency ablation (RFA) has been developed as a new tool in the treatment of non-small-cell lung cancer (NSCLC) in non-surgical patients. There is growing evidence that RFA-mediated necrosis can modulate host immune responses. Here we analysed serum inflammatory factors as well as immunosuppressive cells in the peripheral blood to discover possible prognostic indicators. Peripheral blood and serum samples were collected before RFA and within 3 months after the treatment in a total of 12 patients. Inflammatory cytokines and growth factors were measured in serum by the Bio-Plex assay. Myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs ) were evaluated in the peripheral blood via flow cytometry. In patients developing local or lymphogenic tumour relapse (n=4), we found an early significant increase in the concentration of tumour necrosis factor (TNF)-α as well as chemokine (C-C motif) ligand (CCL)-2 and CCL-4 compared to patients without relapse (n=4) and healthy donors (n=5). These changes were associated with an elevated activity of circulating MDSC indicated by an increased nitric oxide (NO) production in these cells. Elevated serum levels of TNF-α, CCL-2 and CCL-4 associated with an increased NO production in circulating MDSCs might be an early indicator of the incomplete RFA and subsequently a potential tumour relapse in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/imunologia , Mediadores da Inflamação/sangue , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/imunologia , Células Mieloides/imunologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Ablação por Cateter , Contagem de Células , Feminino , Humanos , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Prognóstico , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Tumoral
5.
Ann Oncol ; 25(11): 2237-2243, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25096607

RESUMO

BACKGROUND: Exercise has been reported to decrease cancer-related fatigue and to increase quality of life (QoL) in various breast cancer (BC) populations. However, studies investigating exercise during radiotherapy or resistance training are scarce. We conducted a randomized, controlled trial (BEST study) to assess the efficacy of 12-week resistance training on fatigue beyond possible psychosocial effects of a group-based intervention. PATIENTS AND METHODS: One hundred sixty patients with BC stage 0-III were randomly assigned to a 12-week progressive resistance training (2 times/week) or a 12-week relaxation control (RC, 2 times/week). Both interventions were group-based. The primary end point fatigue was assessed with a 20-item multidimensional questionnaire, QoL with EORTC questionnaires. Statistical analyses were based on analysis of covariance models for the individual changes from baseline to week 13. RESULTS: Adherence to the intervention program as well as the completion rate (97%) for the primary outcome variable fatigue was high. In intention-to-treat analyses for the N = 155 patients, significant between-group mean differences (MD) favoring the exercise group (EX) were observed for general fatigue (P = 0.044), especially for the subscale physical fatigue [MD = -0.8; 95% confidence interval -1.5 to -0.2, P = 0.013], but not for affective (P = 0.91) or cognitive fatigue (P = 0.65). For QoL, significantly larger improvements regarding the role function (P = 0.035) and pain (P = 0.040) were noted among exercisers compared with RCs. Future perspective improved significantly stronger in the RC group compared with the EX group (P = 0.047). CONCLUSIONS: The 12-week resistance training program was a safe, feasible and efficacious strategy to improve cancer-related fatigue and components of QoL in BC patients during adjuvant radiotherapy. As exercise was compared with another group-based intervention, results indicate that resistance training effects on fatigue and QoL go beyond psychosocial benefits, and that the clinically relevant overall benefit of resistance exercise compared with usual care can be assumed to be higher. TRIAL REGISTRATION: ClinicalTrials.gov NCT01468766.


Assuntos
Neoplasias da Mama/radioterapia , Aptidão Física , Radioterapia Adjuvante/efeitos adversos , Treinamento Resistido , Adulto , Idoso , Neoplasias da Mama/patologia , Fadiga/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , Inquéritos e Questionários
7.
Oncogene ; 27(9): 1281-9, 2008 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-17952127

RESUMO

L1 cell adhesion molecule (L1-CAM) is a transmembrane cell adhesion molecule involved in cell migration and axon guidance in the developing nervous system. L1 is also overexpressed in ovarian and endometrial carcinomas and is associated with a bad prognosis. In carcinoma cell lines, L1 overexpression augments cell motility, tumor growth in mice and induces expression of Erk-dependent genes. Here, we show that a mutation in the cytoplasmic portion of L1 (T1247A, S1248A) abrogates Erk activation, blocks cell migration on extracellular matrix proteins and did not augment tumor growth in non-obese diabetic/severe combined immuno-deficient mice. In cells expressing mutant L1, the induction of Erk-dependent genes such as beta3-integrin, cathepsin-B and several transcription factors is eliminated and the invasive phenotype is abrogated. L1 antibodies showed similar effects. They prevented Erk activation and interfered with the Erk-dependent gene expression pattern. These findings provide a rationale for the mode of action of L1 antibodies and suggest that interference with L1 function could become a valuable target for therapy.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Proliferação de Células , Citoplasma/fisiologia , Regulação Neoplásica da Expressão Gênica , Neoplasias/imunologia , Neoplasias/terapia , Molécula L1 de Adesão de Célula Nervosa/fisiologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Citoplasma/química , Feminino , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Invasividade Neoplásica , Neoplasias/genética , Neoplasias/patologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia , Molécula L1 de Adesão de Célula Nervosa/química , Estrutura Terciária de Proteína
8.
Cancer Lett ; 252(2): 290-8, 2007 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-17320278

RESUMO

BACKGROUND: To be effective and selective, immunotherapy ideally targets specifically tumor cells and spares normal tissues. Identification of tumor specific antigens is a prerequisite to establish an effective immunotherapy. Still very little is known about the expression of tumor-related antigens in pancreatic neoplasms. Cancer Testis antigens (CT) are antigens shared by a variety of malignant tumors, but not by normal tissues with the exception of germ cells in testis. Restricted expression in neoplastic tissues and inherent immunogenic features make CT antigens ideal for use in immunotherapy. We analyzed the expression of a selected panel of nine CT antigens that have been proven to elicit an efficient immunogenic response in other malignancies. In addition we analyzed the expression of HERV-K-MEL, an immunogenic antigen of viral origin. METHODS: Pancreatic adenocarcinoma tumor samples (n=130) were obtained intraoperatively, control tissues (n=23) were collected from cadaveric donor and from patients with chronic pancreatitis. Tumor-associated antigen expression of MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, LAGE-1, NY-ESO-1, SCP-1, SSX-2, SSX-4 and HERV-K-MEL was assessed by PCR. Sequencing of PCR products were performed to assess the expression of SSX-4 in neoplastic and normal pancreatic tissues. RESULTS: Three of 10 tested antigens were expressed in over 10% of malignant pancreatic tissue samples. SSX-4 was found positive in 30% of cases, SCP-1 in 19% and HERV-K-MEL in 23% of cases. No expression of CT antigens was found in non-malignant pancreatic tissue with the exception of SSX-4 and and SSX-2. CONCLUSIONS: Fifty two percentage of the analyzed tissues expressed at least one CT antigen. The concomitant expression of SSX-4 in both malignant and non-malignant pancreatic tissue is a new finding which may raise concerns for immunotherapy. However, HERV-K-MEL is expressed with a relatively high prevalence and may be a candidate for specific immunotherapy in a large subgroup of pancreatic cancer patients. This study advocates the analysis of patients with regard to their immunogenic profile before the onset of antigen-specific immunotherapy.


Assuntos
Adenocarcinoma/terapia , Antígenos de Neoplasias/imunologia , Imunoterapia , Neoplasias Pancreáticas/terapia , Adenocarcinoma/imunologia , Azacitidina/administração & dosagem , Sequência de Bases , Primers do DNA , Humanos , Neoplasias Pancreáticas/imunologia
9.
Int J Oncol ; 28(6): 1419-28, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16685444

RESUMO

Pancreatic carcinoma is a very aggressive disease and little is known about its immunobiology. We here describe the presence in pancreatic cancer patients of spontaneously induced functional CD4 and CD8 memory/effector T cells reactive to autologous tumor cells or to the pancreatic cancer associated antigen, MUC-1. Such specific cells were present in the bone marrow or peripheral blood of most of the 23 tested patients. Low dose stimulation of primary cultures of pancreatic cancer cells with 500 IU/ml IFN-gamma for 72 h enhanced HLA-I expression and induced the de novo expression of HLA-II molecules. This led to a much better immune recognition by autologous HLA-I restricted and purified CD8 T cells and allowed tumor cell recognition by HLA-II restricted purified CD4 T-helper cells. Thus, interferon-gamma appears to be a useful adjuvant cytokine to enhance the immunogenicity of a patients' tumor cells and their recognition by tumor reactive immune cells.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Interferon gama/farmacologia , Neoplasias Pancreáticas/imunologia , Idoso , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Células Dendríticas/imunologia , Feminino , Antígenos HLA-D/análise , Antígenos de Histocompatibilidade Classe I/análise , Humanos , Memória Imunológica/efeitos dos fármacos , Interleucina-4/farmacologia , Complexo Principal de Histocompatibilidade , Masculino , Pessoa de Meia-Idade
10.
Int J Oncol ; 20(2): 247-53, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11788884

RESUMO

Dendritic cells (DCs) currently used for vaccination in clinical studies to induce immunity against malignant cells are normally generated from peripheral blood-derived monocytes. Here we studied conditions for the generation of DCs from unseparated human bone marrow (BM) mononuclear cells and compared them functionally with DCs from blood. The two types of DCs, from bone marrow (BM-DC) and peripheral blood (BL-DC), were generated in parallel from the same normal healthy donors by culturing in serum-free X-VIVO 20 medium containing GM-CSF and IL-4, and then the phenotypes and functions were compared. BM-DC generation occurred in 14 days and involved proliferative expansion from CD34 stem cells and differentiation while BL-DC generation occurred in 7 days from CD14 monocytes and involved only differentiation. A 7- to 25-fold higher number of DCs could be obtained from BM than from blood. BM-DC had similar phenotypes as BL-DC. The capacity to stimulate MLR reactivity in allogeneic T lymphocytes was higher with BM-DC than that with BL-DC. Also, the capacity to stimulate autologous memory T cell responses to tetanus toxoid (TT) or tuberculin (PPD) was higher with BM-DC than with BL-DC. These results suggest that BM-DC as produced here may be a very economic and useful source of professional antigen-presenting cells for anti-tumor immunotherapeutic protocols.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular , Células Dendríticas/citologia , Leucócitos Mononucleares/citologia , Apresentação de Antígeno , Tamanho Celular , Células Dendríticas/fisiologia , Endocitose , Citometria de Fluxo , Humanos , Teste de Cultura Mista de Linfócitos , Fenótipo
11.
Nat Med ; 7(4): 452-8, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11283672

RESUMO

In an analysis of 84 primary-operated breast cancer patients and 11 healthy donors, we found that the bone marrow of most patients contained memory T cells with specificity for tumor-associated antigens. Patients' bone marrow and peripheral blood contained CD8+ T cells that specifically bound HLA/peptide tetramers. In short-term culture with autologous dendritic cells pre-pulsed with tumor lysates, patients' memory T cells from bone marrow (but not peripheral blood) could be specifically reactivated to interferon-gamma-producing and cytotoxic effector cells. A single transfer of restimulated bone-marrow T cells into NOD/SCID mice caused regression of autologous tumor xenotransplants associated with infiltration by human T cells and tumor-cell apoptosis and necrosis. T cells from peripheral blood showed much lower anti-tumor reactivity. Our findings reveal an innate, specific recognition of breast cancer antigens and point to a possible novel cancer therapy using patients' bone-marrow-derived memory T cells.


Assuntos
Neoplasias da Mama/imunologia , Neoplasias da Mama/terapia , Linfócitos T/imunologia , Linfócitos T/transplante , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/química , Apoptose , Transplante de Medula Óssea , Neoplasias da Mama/patologia , Feminino , Antígeno HLA-A2/metabolismo , Humanos , Memória Imunológica , Técnicas In Vitro , Interferon gama/biossíntese , Ativação Linfocitária , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mucina-1/química , Mucina-1/imunologia , Necrose , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Receptor ErbB-2/química , Receptor ErbB-2/imunologia , Linfócitos T Citotóxicos/imunologia , Transplante Autólogo , Transplante Heterólogo
12.
Immunology ; 87(2): 303-9, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8698395

RESUMO

Sialoadhesin (SER) is a newly described macrophage-restricted adhesion molecule with a sequence similarity to CD22 on B cells and to myelin-associated glycoprotein on Schwann cells. We describe here a functional role of SER+ spleen macrophages in antigen processing and presentation to T lymphocytes. In two syngeneic murine tumour systems (ESb-MP and lacZ transduced ESbL T-lymphoma cells), the activation state of SER+ macrophages (tested by activity of marker enzymes adenosine deaminase and 5'-nucleotidase) correlated with the arrest of lymphoma metastasis. Furthermore, this macrophage subpopulation became activated upon anti-tumour immunization as well as upon adoptive transfer of immune T lymphocytes into tumour-bearing hosts. We suggest that in situ-activated SER+ macrophages contribute to host resistance against metastasis.


Assuntos
Moléculas de Adesão Celular , Linfoma/imunologia , Macrófagos/imunologia , Glicoproteínas de Membrana , Receptores Imunológicos , Baço/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Imunoterapia Adotiva , Linfoma/terapia , Macrófagos/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Metástase Neoplásica , Transplante de Neoplasias , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico , Células Tumorais Cultivadas
13.
Int J Oncol ; 6(3): 505-21, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21556565

RESUMO

A cellular cancer therapy is described with unique efficiency even in late-stage disease. in situ activated tumor-immune T cells, induced in allogeneic, tumor-resistant, MHC identical but superantigen different donor mice (B10.D2) could transfer strong graft-versus-leukemia (GvL) effects accompanied by only mild graft-versus-host (GvH) reactivity. Systemic immune cell transfer into 5 Gy irradiated DBA/2 mice bearing up to 4 week established syngeneic tumors and macrometastases led to massive infiltration of tumor tissues by CD4 and CD8 donor T lymphocytes. Upon interaction of immune CD4 donor T cells with host antigen presenting cells in synergy with immune CD8 donor T cells attacking the tumor cells directly, primary tumors (1.5 cm diameter) were encapsulated and rejected from the skin and liver metastases eradicated. For the first time, such adoptive cellular immunotherapy (ADI) was followed in individual live animals by P-31-NMR spectroscopy of primary tumors. An approximately 25,000 fold excess of metastatic tumor cells could be rejected as revealed quantitatively by FACScan analysis of lacZ gene transfected tumor cells.

14.
Proc Natl Acad Sci U S A ; 91(16): 7430-4, 1994 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-8052600

RESUMO

Live proliferation-competent and irradiated proliferation-incompetent L5178 murine lymphoma cells (Eb cell line) were compared for their potency to induce systemic anti-tumor immunity in syngeneic DBA/2 mice. The tumorigenic potential in vivo of live Eb cells was suppressed through local secretion of interleukin 4 (IL4) or alternatively by injection of parental cells at a site refractory to tumor growth. Inoculation of nontumorigenic doses of live Eb or Eb-IL4 cells led to long-lasting specific and systemic T-cell-mediated antitumor response requiring both CD4+ and CD8+ T lymphocytes. Irradiated cells offered only limited short-term protection, which could be marginally improved by IL4. The more effective protection offered by vaccination with live tumor cells correlated with rapid migration and persistence of tumor cells in the bone marrow of host animals after tumor cell inoculation. In contrast, irradiated Eb-lacZ cells had a short persistence. Tumor cells recovered from the bone marrow of host animals injected with live Eb-IL4 cells still expressed IL4. These observations indicate that in the course of vaccination with live Eb or Eb-IL4 cells, a fraction of these cells escaped destruction by host mechanisms and persisted in a dormant state in the bone marrow for long periods of time. Persistence of dormant tumor in the bone marrow correlated with the duration of anti-tumor immunity.


Assuntos
Memória Imunológica , Leucemia L5178/imunologia , Leucemia L5178/prevenção & controle , Vacinação , Animais , Medula Óssea/patologia , Sobrevivência Celular , Imunidade Celular , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos DBA , Vacinas Atenuadas/uso terapêutico
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