ABSTRACT
Foxp3+ CD25+CD4+ regulatory T (Treg) cells are crucial for the maintenance of immunological self-tolerance and are abundant in tumors. Most of these cells are chemo-attracted to tumor tissues and suppress anti-tumor responses inside the tumor. Currently, several cancer immunotherapies targeting Treg cells are being clinically tested. Cisplatin is one of the most potent chemotherapy drugs widely used for cancer treatment. While cisplatin is a powerful drug for the treatment of multiple cancers, there are obstacles that limit its use, such as renal dysfunction and the development of cisplatin-resistant cancer cells after its use. To minimize these barriers, combinatorial therapies of cisplatin with other drugs have been developed and have proven to be more effective to treat cancer. In the present study, we evaluated the eff ect of the combination therapy using methyl gallate with cisplatin in EL4 murine lymphoma bearing C57BL/6 mice. The combinatorial therapy of methyl gallate and cisplatin showed stronger anti-cancer eff ects than methyl gallate or cisplatin as single treatments. In Treg cell-depleted mice, however, the eff ect of methyl gallate vanished. It was found that methyl gallate treatment inhibited Treg cell migration into the tumor regardless of cisplatin treatment. Additionally, in both the normal and cisplatin-treated tumor-bearing mice, there was no renal toxicity attributed to methyl gallate treatment. These findings suggest that methyl gallate treatment could be useful as an adjuvant method accompanied with cisplatin therapy.
Subject(s)
Animals , Mice , Cisplatin , Drug Therapy , Immunotherapy , Lymphoma , T-Lymphocytes, RegulatoryABSTRACT
The objectives of this study were to investigate the effects of <i>Hericium erinaceum</i> (Yamabusitake) and <i>Grifola frondosa </i>(Maiteke) on the proliferation for EL4-tumor and immunoregulatory function by flow cytometory.<br> It was found that Yamabushitake and Maitake tend to inhibit the proliferation of EL4-tumor individually. In the flow cytometory analysis, Maitake-treatment showed the preserve effect against the depression effect by bearing EL4-tumor on cytotoxic T cell and NK-cell from spleen cell. This effect was shown more clear in the group of mixture Yamabusitake and Maitake.<br>
ABSTRACT
Objective: To investigate the expression of p53 protein in the adaptable reaction of EL-4 cells induced by low dose ionizing radiation (LDR), which may provide the experimental clues for studying the repair mechanism of DNA damage in the adaptable reaction of ELA cells induced by LDR. Methods: EL-4 cells were divided into control group, radiation groups (the radiation dosage was 1, 2, and 3 Gy), and adaptable radiation groups (75 mGy + 1 Gy, 75 mGy + 2 Gy, and 75 mGy + 3 Gy). The p53 mRNA and protein expression in EL-4 cells was measured by flow cytometry and RT-PCR methods, respectively. Results: The expression levels of p53 protein in the three adaptive radiation groups were significantly higher than the normal control group (P<0.01). Adaptive radiation at 75 mGy induced adaptable reaction of EL-4 cells and decreased the expression level of p53 protein compared with control group (P<0.01). The expression level of p53 mRNA showed the same change as its protein level in EL-4 cells. Conclusion: The expression level of p53 protein is decreased in the adaptive radiation group, which suggests that p53 might play important roles in the adaptable reaction of EL-4 cells induced by LDR.
ABSTRACT
Objective:To assess the potential of mouse immune-costimulating signal B7-2 in inducing immune effect.Methods:(1)The specific mB7-2cDNA fragment from LPS-stimulated mouse splenocytes was obtained by reverse transcription and polymerase chain reaction.The obtained fragment was inserted to pLXSN plasmid.Then the plasmid pLXSN-mB7-2 was packaged into PA317 cells;(2)The EL4/mB7-2 was obtained by infecting the EL4 by the concentrated virus particles produced by PA317/mB7-2;(3)In vitro,the secretion of IL-2 of EL4/mB7-2 stimulated-lymphocytes was detected by using mixed lymphocytes culture.Results:pLXSN-mB7-2 and transgenetic EL4/mB7-2 cells were obained successfully.IL-2 production in 24h in the supernatant stimulated by EL4/mB7-2 was much higher than wild EL4 cells.Conclusion:EL4/mB7-2 can activated T cell to produce IL-2.This research lay foundation for the research of the function of immune-costimulating signal in the tumor immunity and treatment,the mechanism of autoimmune disease and organ transplantation.
ABSTRACT
Transforming growth factor-B1 (TGF-B1) is well known to be one of the most potent Immunosuppressive cytokines. To determine whether TGF-B1 secreted in the latent form can be immunoregulatory, TGF-B1 cDNA driven by the human -actin promotor was transfected into a murine thymoma cell line, EL4 cells. The transfectants (ELJ4) secreted a latent torm of TGF-B1 at a concentration of 5 ng/ml under the influence of TPA. Transfected TGF-b1 transcripts was readily detected by RT-PCR in ELJ4 cells regardless of the presence of TPA, but not in EL4 cells. In addition, we found the degree of Thy-B1 expression, IL-2 secretion and the proliferation rate are not altered by the transfection. Finally, EL4 and ELJ4 cells were injected into C57BU6 mice (syngenic strain), subcutaneously. Tumor cell masses derived from both cell populations survived longer than 1 wk, and the size of tumor derived from ELJ4 was three times larger (2.5 cm of diameter) than that from EL4. Virtually, there was no histopathological difference between two tumors. Taken together, the results from the present study indicates that EL4 thymomas transfected with TGF-1 secretes a latent form of TGF-B1 which may suppress host immune defence system.
Subject(s)
Humans , Mice , AnimalsABSTRACT
The Mcr systems (previously known as Rgl systems) of Escherichia coli recognize and cleave specific sequences carrying methylated or hydroxymethylated cytosines. We have cloned the mcrA gene and determined its nucleotide sequence. An 831 base pair sequence encodes the McrA protein. Analysis of the sequence data reveals that there arc additional ORFs internal to the above. A phage T7 expression system was used to determine the protein products encoded by the cloned mcrA gene. The results clearly show that a 31 kDa polypeptide is responsible for McrA activity. This is in agreement with the molecular weight deduced from sequence data. McrA protein was found to be localized in the outer membrane of Escherichia coli. To our knowledge this is the first restriction enzyme localized in the outer membrane of Escherichia coli.
ABSTRACT
The filter elution technique was used to assay Co-60 g ray-induced DNA single-strand breaks (SSB) in EL 4 mouse leukemia cell and spleen lymphocyte. The lymphocytes were stimulated with lipopolysaccharide (LPS, 20 mug/ml) to label [3H] thymidine. EL 4 cells and lymphocytes in suspension were exposed at 0degree C to gy, 1 gy, 5 gy, 10 gy of Co-60 radiation and elution procedure was performed at PH 12.1. The number of DNA single-strand breaks increased with increasing doses of g rays. The strand scission factor (SSF) was estimated in each experiment (eluted volume 21 ml. The slope for EL 4 cells was 0.01301+/-0.00096 gy-1(n=5) and the slope for lymphocytes was 0.01097+/-0.00091 gy-1(n=5). The slopes were significantly different (p<0.005). Thus EL 4 cells were more sensitive to induction of DNA SSB by ionizing radiation than lymphocytes.