ABSTRACT
The equal importance of the qualitative and quantitative characteristics of antigen presentation as well as the set of costimulatory signals provided by antigen presenting cells to T-cells in determining the outcome of T-cell responses at the time of antigen recognition is now clear. Moreover, an important function in innate mechanisms has been recently attributed to costimulatory molecules demonstrating their relevant role in different stages of immune response. In this paper, we demonstrated the ability of CD40L (CD154) and CD80 costimulatory molecules expression in a T-cell lymphoma to induce both T-cell dependent and independent immune responses leading to an important anti-tumor effect. CD40 expression by LBC cells enhanced only T-cell dependent anti-tumor immune response resulting in tumor rejection. Furthermore, this work represents the first report to describe complete tumor rejection after co-inoculation of lymphoma cells transfected with CD40L and CD80 in either presence or absence of CD40 expressing lymphoma cells. In addition, this synergistic effect resulted in long lasting immunity to parental tumor cells. Co-inoculation of tumor cells each genetically modified to express a different costimulatory molecule circumvents the need to co-transfect genetically unstable tumor cells and represents an option for those weakly or non-immunogenic tumors where either treatment alone proved to be inefficient. This strategy represents a promising approach for inducing anti-tumor immunity and provides a new rational design of cancer therapies.
Subject(s)
B7-1 Antigen/metabolism , CD40 Antigens/metabolism , CD40 Ligand/metabolism , Graft Rejection , Lymphoma, T-Cell/immunology , Neoplasms, Experimental/immunology , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , Cancer Vaccines/immunology , Cell Line, Tumor , Cytotoxicity, Immunologic , Lymphocyte Activation , Lymphoma, T-Cell/therapy , Mice , Mice, Inbred BALB C , Mice, NudeABSTRACT
In transfection protocols, the expression levels of the transgene is important to define, still is difficult to obtain in certain cell lines such as those derived from T-lymphoma cells. In this study we evaluate transgene expression kinetics in the presence and absence of two well known transcription activators such as phorbol-12-myristate13-acetate (PMA) and Ionomicin (IO). Three murine T lymphoma cell lines (LBC, EL4 and BW5147) were transfected by electroporation using green fluorescent protein (GFP) as a reporter gene and analyzed by flow cytometry. Addition of PMA/IO resulted in a significant increase of the Mean Fluorescence Intensity but not in GFP-positive cell percentages, either in transient or stable transfected LBC and EL4 cells. Remarkable, BW5147 cells showed low GFP induction with a significant increment only in stable transfected cells. Our results demonstrated that CMV promoter activity can be enhanced in transfected lymphoma cells by PMA/IO suggesting that transgene expression levels can be optimized by means of the use of transcription activators.
Subject(s)
Gene Expression , Promoter Regions, Genetic/genetics , Transfection/methods , Transgenes/genetics , Animals , Cell Line, Tumor , Electroporation , Flow Cytometry , Gene Expression/drug effects , Green Fluorescent Proteins/genetics , Ionomycin/pharmacology , Lymphoma, T-Cell , Mice , Plasmids , Tetradecanoylphorbol Acetate/pharmacologyABSTRACT
We studied the role of IL-2, IL-15, IL-10, TNF and IL-2 receptor complexes (IL-2R) produced constitutively by a T-cell lymphoma line (LBC) on their own proliferation. The constitutive expression of surface alpha, beta and gamma chains IL-2R was detected in tumor cells by flow cytometry. Using reverse-transcription PCR, mRNA for IL-2, IL-15, IL-10 and TNF were found to be present in LBC. In addition, tumor cells were found to constitutively express intracellular IL-2, IL-15, IL-10 and TNF. Despite the production of these cytokines by tumor cells, specific neutralising antibodies did not inhibit LBC proliferation; surprisingly, anti-IL-15 increased LBC cell growth. We also demonstrated that recombinant IL-2 or IL-15 enhanced LBC cell proliferation. Our data suggest that endogenous IL-2 and IL-15 may trigger the proliferation of lymphoma LBC cells, and so their growth could be regulated, at least partly, by IL-2/IL-15/IL-2R system. In addition, IL-10 and TNF, immunosuppressor and pro-metastatic cytokines, respectively, may promote the in vivo growth of the tumor. The fact that leukaemia-lymphoma cells produce simultaneously both IL-2 and IL-15 should be taken into consideration in the design of immunotherapy protocols directed to IL-2R.
Subject(s)
Interleukin-10/physiology , Interleukin-15/physiology , Interleukin-2/physiology , Lymphoma, T-Cell/metabolism , Tumor Necrosis Factor-alpha/physiology , Animals , Cell Division , Cell Line, Tumor , Cytokines/metabolism , Flow Cytometry , Mice , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Time FactorsABSTRACT
El control de calidad se efectuó sobre los valores obtenidos, relativos y absolutos, de linfocitos T y de sus subpoblaciones CD4+ y CD8+ en muestras de sangre de pacientes infectados con el virus de la inmunodeficiencia humana (HIV). El estudio incluyó dieciocho centros: diez utilizaron citómetros de flujo de Becton Dickinson, tres de Coulter y 5 de Ortho que representan a 17 laboratorios de Argentina y a uno de Uruguay. Los siguientes programas se utilizaron para analizar los datos : SimulSET, Paint a Gate (Becton Dickinson), Profile II, XL System (Coulter), ImmunoCount Trio y Combo Cytoron (Ortho). Se obtuvieron muestras de sangre periférica en horas de la mañana (8 a 10 hs) de 10 voluntarios normales (por serología y hemograma) y de 10 pacientes HIV positivos con valores previos de CD4 que variaron entre 200-350 células por microlito y fueron procesadas dentro de las 12 horas. Cada centro obtuvo los valores relativos con el procedimiento técnico habitual y el de los valores absolutos utilizando el hemograma propio. Además, en un contador hematológico Cell-Dyn 3500 se obtuvo para cada muestra el hemograma correspondiente considerado de referencia. Los valores absolutos medios, obtenidos en cada centro con el hemograma propio, para los linfocitos T y los de sus subpoblaciones fueron significativamente diferentes. No hubo diferencias significativas para los valores porcentuales entre los diferentes centros ni para los valores absolutos obtenidos con el hemograma de referencia. Concluimos que las diferencias en los valores absolutos de los linfocitos T y sus subpoblaciones dependen del recuento hematológico empleado. (AU)
Subject(s)
Humans , Male , Female , Adult , Flow Cytometry/methods , Multicenter Studies as Topic , Quality Control , Lymphocyte Subsets , CD4-Positive T-Lymphocytes , CD8-Positive T-Lymphocytes , HIV , Data Interpretation, Statistical , Blood Specimen Collection , CD4 Lymphocyte Count/methodsABSTRACT
El control de calidad se efectuó sobre los valores obtenidos, relativos y absolutos, de linfocitos T y de sus subpoblaciones CD4+ y CD8+ en muestras de sangre de pacientes infectados con el virus de la inmunodeficiencia humana (HIV). El estudio incluyó dieciocho centros: diez utilizaron citómetros de flujo de Becton Dickinson, tres de Coulter y 5 de Ortho que representan a 17 laboratorios de Argentina y a uno de Uruguay. Los siguientes programas se utilizaron para analizar los datos : SimulSET, Paint a Gate (Becton Dickinson), Profile II, XL System (Coulter), ImmunoCount Trio y Combo Cytoron (Ortho). Se obtuvieron muestras de sangre periférica en horas de la mañana (8 a 10 hs) de 10 voluntarios normales (por serología y hemograma) y de 10 pacientes HIV positivos con valores previos de CD4 que variaron entre 200-350 células por microlito y fueron procesadas dentro de las 12 horas. Cada centro obtuvo los valores relativos con el procedimiento técnico habitual y el de los valores absolutos utilizando el hemograma propio. Además, en un contador hematológico Cell-Dyn 3500 se obtuvo para cada muestra el hemograma correspondiente considerado de referencia. Los valores absolutos medios, obtenidos en cada centro con el hemograma propio, para los linfocitos T y los de sus subpoblaciones fueron significativamente diferentes. No hubo diferencias significativas para los valores porcentuales entre los diferentes centros ni para los valores absolutos obtenidos con el hemograma de referencia. Concluimos que las diferencias en los valores absolutos de los linfocitos T y sus subpoblaciones dependen del recuento hematológico empleado.
