Role of cytokines and gene expression characteristics in cultured lymphocytes ex vivo for adoptive immunotherapy / 中国实验血液学杂志

Different cytokines are needed in the course of culturing cells to do adoptive immunotherapy. This study was aimed to investigate the differentiation directions of lymphocytes and related gene expression characteristics after combined stimulation of lymphocytes by different cytokines or EBV antigen peptide combined with cytokines. The experiment was divided into 4 groups. The levels of total T lymphocytes (CD3(+)), T helper lymphocytes (CD3(+)CD4(+)), cytotoxic T-lymphocyte (CD3(+)CD8(+)), memory T cells (CD3(+)CD8(+)CD45RO(+)), naive T cells (CD3(+)CD8(+)CD45RA(+)), Th2 cells (CD3(+)CD30(+)), B cells (CD19(+)), NK cells (CD56(+)), naive T regulatory cells (CD4(+)CD25(+)), precise T regulatory cells (CD4(+)CD25(+)FOXP3(+)) were detected by flow cytometry. The expression levels of house-keeping gene (mad1, pten), T helper cells transcriptional regulatory gene t-bet (Th1), gata3 (Th2), cytokine IFN-γ(Th1), IL-4(Th2) were detected by using RT-PCR. The results showed that CTL in EBV polypeptide group were dominant cells with certain clinical effects. Comparison of result of EBV polypeptide group with other 3 different cytokine stimulating groups demonstrated that EBV antigen peptide had much more effects on stimulating CTL generation. The expression of IFN-γ gene was significantly increased; the T helper differentiation-related gene t-bet, gata3 also increased evidently, while expression change of house-keeping gene mad1 and pten were not evident. Addition of different cytokines and antigen peptides in culture may be much more effective on stimulating CTL generation. It is concluded that specific CTL can be obtained by using the lymphocytes co-cultured with EBV and cytokines, and the different cytokines play different roles in cell differentiation.

Changes of T-cell clonality after induction-cultivation of peripheral T lymphocytes in adoptive immunotherapy for leukemias / 中国实验血液学杂志

This study was purposed to analyze the changes of T-cell clonality after induction of peripheral T lymphocytes by autogenous DC and cytokines in the preparation of adoptive immunotherapy for leukemias. The bone marrow and peripheral blood from 21 leukemia patients at remission stage after treatment and subjected to adoptive immunotherapy were collected. Their DCs and T-cells were stimulated with cytokines and then were mixed to activate T-cells. T-cell receptor beta variable region (TCRBV) families were amplified by RT-PCR, and genescan method and sequencing of the PCR products were used to observe the clonality changes of T-cells before and after the induction and cultivation of T-cells. The flow cytometry was used to identify CD3(+), CD4(+), CD8(+), CD3(+)CD56(+) and CD4(+)CD25str(+)FOXP3(+) cells to disclose the ratio change of cytotoxic T lymphocytes (CTL), helper T-cells, regulatory T-cells and NK T-cells before and after induction and cultivation of T-cells. The results showed that in the 21 patients, most of the 24 TCRBV families presented as oligoclonal distribution on genescan, several families were not expressed, and only a few families remained polyclonal. TCRBV24 was found to be oligoclonal in all of the 21 patients. DNA sequence analysis of TCRBV24 revealed a common motif of VAG in CDR3 in 3 cases and a common motif of GGG in CDR3 in 2 cases. In patient 5, both TCRBV 24 and TCRBV8 contained the same motif of GGG in CDR3. The identical motif in these patients may suggest that these T-cells recognize the same antigen. The peripheral lymphocytes demonstrated recovery of clonal profile on genescan from oligoclonal profile and absence of several families before the induction and cultivation to typical polyclonal profile in all TCRBV families after the induction by DC and cytokines for 13 days. After the induction and cultivation, the number of lymphocytes increased to 3.38 +/- 1.20 times. CD3(+), CD4(+), CD8(+), CD3(+)CD56(+) and CD4(+)CD25str(+)FOX P3(+) cells were 71.1 +/- 11.8%, 26.7 +/- 11.4%, 35.7 +/- 12.9%, 3.1 +/- 1.6% and 0.12 +/- 0.1% respectively before the induction and cultivation, and changed to 95.4 +/- 3.2% (p < 0.01), 27.0 +/- 13.1% (p > 0.01), 55.5 +/- 13.8% (p < 0.01), 9.8 +/- 6.1% (p < 0.01) and 0.22 +/- 0.18% (p < 0.01) respectively after the induction and cultivation. It is concluded that the major action of this induction and cultivation method on T-lymphocytes in vitro is the promotion of CTL and NK T-cell proliferation. In leukemic patients at the remission stage, the TCRBV profile is characterized by the oligoclonal proliferation of T-lymphocytes. Several proliferated clones may have the same motif in CDR3, suggesting the recognition of the same antigen by these lymphocyte clones. Cytokine induction and co-culture with autogenous DCs can stimulate the T-lymphocytes to recover their immunocompetence as manifested by the polyclonal profile and the proliferation of CTL and NK-T cells.

T cells recognizing EBV-epitopes arose in co-culture of peripheral blood mononuclear cells from EB-infected patients and dendritic cells loaded with LMP2-mixed peptides / 中国实验血液学杂志

The latent membrane protein 2 (LMP2) is a kind of protein expressed by EBV-infected cells. This study was aimed to investigate whether the stimulation of peripheral blood mononuclear cells with peptides induces EBV-specific cytotoxic T lymphocytes (CTL). The peptides were mixture of LMP2 protein and available for people with different HLA types. Peripheral blood sample was collected from a patient with EBV-associated hemophagocytic syndrome. The mononuclear cells were isolated and cultured to obtain dendritic cells (DCs). Immature DCs were pulsed with MIX-LMP2 and added with different maturation-promoting factors. The auto-T lymphocytes were stimulated weekly with the harvested mature DCs loaded with MIX-LMP2, and totally for two times. Part of isolated lymphocytes was cultured without any stimulation as control. T-cell receptor (TCR) beta spectratyping was used to analyze the distribution of different T cell subgroups before and after culture. The phenotype of T lymphocytes was determined by flow cytometry. The IFN-gamma assay was used to estimate specific cytoxic activity of the cultured T cells. The results showed that the distribution of TCRbeta was changed according to analysis of TCR spectratypes. From the distribution of gene families of TCRbeta, the T lymphocytes were oligoclonal before culture, but shifted to a polyclonal after culture in vitro like the normalization of TCR diversity, suggesting the subgroups of lymphocyte could return to normal. The percentage of CD3+, CD3+CD8+ CD3+ CD45RA- CD45 RO+ on T lymphocytes from freshly isolated mononuclear cells were 70.73%, 42.99%, 27.56% respectively. After being stimulated twice with DC loaded with MIX-LMP2, they further increased to 95.17%, 52.54% and 81.41%. The percentages of CD3-CD56+ NK cells and CD4+CD35+ FOXP3+ regulation T cells seldom changed, from 2.12%, 0.03% to 2.35%, 0.02% respectively. The increase of CD3+CD45RA-CD45RO+ cells obviously indicated that most naive T cells could be activated. ELISA for IFN-gamma showed that when DCs loaded with LMP2 peptide were used as target cells, IFN-gamma level secreted by the T cells stimulated with LMP2 peptide-pulsed DCs was 805+/-16 pg/ml and 1729+/-49 pg/ml, the IFN-gamma level secreted by T cells stimulated twice with LMP2 peptide-pulsed DCs was 956+/-23 pg/ml and 2325+/-58 pg/ml respectively at effector-target ratios of 10:1 and 10:2. They were both significantly higher than that secreted by T cells without any stimulation (441+/-27 pg/m and 557+/-19 pg/ml) (p<0.05). But DCs unpulsed with LMP2 peptide were used as target cells, there were no significant differences between the T cells stimulated with LMP2 peptide-pulsed DCs and the T cells without stimulation (p>0.05). It is concluded that the antigen specific T cells recognizing EBV epitopes can be obtained by using DCs pulsed with MIX-LMP2 peptide in vitro, meanwhile the distribution of T cell subgroups can be changed and normalized.