Bone Marrow T Cells are Superior to Splenic T Cells to Induce Chimeric Conversion After Non-Myeloablative Bone Marrow Transplantation

BACKGROUND/AIMS: The bone marrow functions not only as the primary B-lymphocyte-producing organ but also as a secondary lymphoid organ for CD4 and CD8 cell responses and a site of preferential homing and persistence for memory T cells. Bone marrow T (BM-T) cells are distinguished from peripheral blood T cells by surface phenotype, cytokine secretion profile, and immune functions. In this study, we evaluated the alloreactive potential of donor lymphocyte infusion (DLI) using BM-T cells in mixed chimerism compared to that using spleen T (SP-T) cells. METHODS: Cells were prepared using established procedures. BM-T cells were obtained as a by-product of T-cell depletion in BM grafting and then cryopreserved for subsequent DLI. We performed DLI using BM-T cells in allogeneic mixed chimera mice on post-BMT day 21. RESULTS: When the same dose of T cells, 5-10x10(5) (Thy1.2+), fractionated from BM and spleen were administered into mixed chimeras, the BM-T group showed complete chimeric conversion, with self-limited graft-versus-host disease (GVHD) and no pathological changes. However, the SP-T group showed persistent mixed chimerism, with pathological signs of GVHD in the liver and intestine. CONCLUSIONS: Our results suggest that DLI using BM-T cells, even in small numbers, is more potent at inducing chimeric conversion in mixed chimerism than DLI using SP-T cells. Further study is needed to determine whether cryopreserved BM-T cells are an effective cell source for DLI to consolidate donor-dominant chimerism in clinical practice without concerns about GVHD.

Practical Evaluation of Engraftment and Mixed Chimerism Using PCR Amplification of a Microsatellite in the Class II Eb Gene in Murine MHC-mismatched, Nonmyeloablative Bone Marrow Transplantation

BACKGROUND: Although engraftment following murine allogeneic bone marrow transplantation (BMT) is most commonly confirmed by H2 typing using flow cytometry, recipient mice can be seriously injured during peripheral blood (PB) sampling. Therefore, we developed an alternative DNA-based assay that does not require the large volume of PB necessary for flow cytometry. METHODS: A minute volume of PB from the tail vein was used to evaluate the engraftment by PCR amplification of a microsatellite in the class II Eb gene. Dilution experiments were performed to evaluate the sensitivity of this assay for detecting donor cells in mixed cell populations compared with flow cytometry analysis. RESULTS: Early engraftment and mixed chimerism were confirmed, based on the length variation of the microsatellite in the class II Eb gene. The degree of donor chimerism in the donor-recipient cell mixture could be estimated semiquantitatively in a dilution experiment. The sensitivity of this assay by the naked eye approached 10% of the degree of donor chimerism. CONCLUSION: PCR amplification of a microsatellite in the class II Eb gene can be a useful alternative to flow cytometry for evaluating early engraftment and mixed chimerism following murine nonmyeloablative BMT.

Effects of cell growth inhibition on the combination of cisplatin with green tea extracts / 부인종양

OBJECTIVE: The chemotherapeutic agent cisplatin (cis-diamminedichloroplatinum (II)) is particularly effective against cervical cancer. The purpose of this study is to elucidate combination effect of cisplatin and green tea extracts on the growth inhibition of TC-1 cell. METHODS: To observe the anti-proliferative effects, we treated different doses of cisplatin (0.1, 0.5, 2.5 uM), GTP (1, 5, 25 ug/ml) and EGCG (25, 50, 100 uM). to TC-1 cells. Also, we treated 0.5 uM of cisplatin and different doses of GTP (1 and 5 ug/ml) or EGCG (25 and 50 uM). Cell viability was scored by use of MTT assay. In addition, E6 gene expression patterns in TC-1 cell were investigated by using RT-PCR. RESULTS: Cell growth inhibition in a dose dependent was observed at the different concentration of ciaplatin, GTP and EGCG. Also, in the groups treated by 0.5 uM of cisplatin and GTP (1 and 5 ug/ml) or EGCG (25 and 50 uM), the inhibition of cell growth showed with 12.2%, 6.9% and 63.4%, 72.2% as compared to the group treated by cisplatin only. In RT-PCR, down regulation of E6 was shown. CONCLUSION: Additive effect of the combination of cisplatin with GTP or EGCG on the inhibition of cell growth was observed. This effect suggests the possibility lowering the concentration of chemotherapeutic drugs, which alleviate the side effect of drugs.