OBJECTIVETo investigate the gene expression of 4-1BB in peripheral blood mononuclear cells (PBMCs) and the possible significance of the 4-1BB pathway after clinical orthotopic liver transplantation (OLT).

METHODS4-1BB mRNA levels in PBMCs from 22 OLT patients were analyzed by RT-PCR. 4-1BB protein expressed on the surface of CD(4)(+) and CD(8)(+) T cells were detected by flow cytometry, and visualized with direct immunofluorescence and confocal fluorescence microscopy. Patients with primary liver cancer (PLC) and healthy volunteers served as controls. Six cases of recently performed liver transplantation were also observed in this study.

RESULTS4-1BB mRNA was detected in PBMCs from both liver transplant patients with long-term graft acceptance (22 cases) and from transplant patients on day 1 to day 3 post-transplantation (6 cases), but was not found in PBMCs from transplant patients on day 7 to day 30 post-transplantation (6 cases). 4-1BB mRNA was also not found in samples from 8 of the healthy controls and 7 of the PLC patients, though very low expression was detected in the other 4 healthy volunteers and 6 PLC patients. Simultaneously, 4-1BB protein was expressed at nearly undetectable levels on CD(4)(+) and CD(8)(+) T cells from healthy controls, PLC patients, as well as OLT patients within the first month post-transplantation (6 cases). However, 4-1BB expression was found on the surface of CD(4)(+) and CD(8)(+) T cells from liver transplant patients with long-term graft acceptance. Direct immunofluorescent staining and confocal fluorescence microscopy clearly revealed evidence of 4-1BB protein on cell membranes of CD(4)(+) and CD(8)(+) T cells from liver transplant patients with long-term graft acceptance. Simultaneously, a significantly higher percentage of CD(3)(+) CD(25)(+) T cells were found in liver transplant patients with long-term graft acceptance group as compared with the healthy control group (P < 0.05). The expression of 4-1BB protein on T cells did not correlate with the survival time of OLT patients postoperation.

CONCLUSIONSThis study demonstrates that although patients remain in stable condition after liver transplantation under the treatment of immunosuppressants, activated T cells are present to some extent and 4-1BB protein may be involved in this process. Effector T-cells can exert permanent immunoresponses against grafts under these circumstances. Therefore, we conclude that a new immune response balance is established under the combination of both treatment with immunosuppressants and natural immune responses against alloantigens. Manipulation of the 4-1BB/4-1BBL pathway may provide a therapeutic technique for prolonging graft survival.

Adult ; Antigens, CD ; Female ; Gene Expression ; Humans ; Leukocytes, Mononuclear ; chemistry ; Liver Transplantation ; Male ; Middle Aged ; Receptors, Nerve Growth Factor ; genetics ; physiology ; Receptors, Tumor Necrosis Factor ; genetics ; physiology ; Tumor Necrosis Factor Receptor Superfamily, Member 9

Animals ; CD4-Positive T-Lymphocytes ; metabolism ; Chemical and Drug Induced Liver Injury ; immunology ; metabolism ; Concanavalin A ; adverse effects ; Disease Models, Animal ; Interleukin-2 Receptor alpha Subunit ; metabolism ; Male ; Mice ; Mice, Inbred Strains ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; metabolism

OBJECTIVETo observe the effect of the costimulatory molecules CD137 and CD28 on Bcl-2 expression in T cells of mice with D-galactose-induced aging and natural aging.

METHODSSeven-week-old male BALB/c mice were injected daily with D-galactose (120 mg/kg) for 5 months to induce subacute aging, and 16-month-old male BALB/c mice served as the natural aging group. The spleen T cells of were isolated from the rats and stimulated in vitro with conA+IgG, conA+CD137 mAb or conA+CD28 mAb for 48 h. Bcl-2 expression of T cells was detected by flow cytometry and semi-quantitative RT-PCR.

RESULTSIn the subacute aging group, Bcl-2 protein expression rate in the T cells stimulated with conA+IgG, conA+CD137 mAb and conA+CD28 mAb were (24.4-/+1.5)%, (34.4-/+2.4) %, and (45.1-/+2.7) %, which were (19.6-/+2.0) %, (26.3-/+1.9) %, and (48.5-/+2.2) % in the natural aging group, respectively. In vitro stimulation with conA+IgG, conA+CD137 mAb and conA+CD28 mAb resulted in expression rate of bcl-2 mRNA in the T cells of 0.309-/+0.039, 0.547-/+0.036, and 0.780-/+0.041 in the subacute aging group, and 0.283-/+0.038, 0.535-/+0.041, and 0.771-/+0.063 in the natural aging group, respectively.

CONCLUSIONCD137 and CD28 can promote bcl-2 expression at both mRNA and protein level in T cells in aging mice, which may be one of the mechanisms through which CD137 and CD28 molecules inhibit aging T cell apoptosis and maintain their function.

Animals ; CD28 Antigens ; metabolism ; Cellular Senescence ; Gene Expression Regulation ; Male ; Mice ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; T-Lymphocytes ; cytology ; metabolism ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; metabolism

This study was aimed to investigate the expression characteristics of new co-stimulatory molecule CD137 (4-1BB) on human T lymphocytes and antileukemic effects of monoclonal antibody hCD137mAb in stimulating the T lymphocyte proliferation, promoting the cytokine secretion, enhancing the cell killing effect and so on. The expression of CD137 on normal T lymphocytes treated with phytohemagglutinin (PHA) was detected by FACS and indirect immunofluorescence. In HL-60 and T lymphocyte system in vitro, the effect of hCD137mAb and PHA on T lymphocyte proliferation was tested by MTT colorimetric assay. The IFN-gamma and IL-4 expression levels on the surface of T cells were detected by FACS and indirect immunofluorescence. In vitro mixed lymphocyte tumor cell culture (MLTC) system, the function of hCD137mAb enhancing toxicity killing leukemic cells at different effect-target ratio were studied. The results showed that almost no expression of hCD137 was found in T cells without PHA stimulation, but after activation of T cells by PHA, the expression gradually increased with a peak at 7th day (FACS 56.4%+/-1.98%, indirect immunofluorescence 52.8%+/-2.01%). CD137mAb alone could not stimulate T cell proliferation (proliferation index 1.002+/-0.011), but could enhance PHA stimulating activity (proliferative index of 2.161+/-0.102) about 2-folds (proliferation index 4.705+/-0.133). Moreover, hCD137mAb increased expression of IFN-gamma high by about 3-fold in presence of PHA, but did not effect on IL-4. The hCD137mAb markedly enhanced T cell killing activity on HL-60 cell line and its co-stimulatory effect was best at the effect-target ratio of 40:1 with increasing of killing percentage by about 2-fold. It is concluded that the new co-stimulatory molecule CD137 has significant antileukemic effect, use of hCD137mAb is an effective, safe and simple immunization strategy for leukemia therapy, this study provides some experimental basis for clinical immunotherapy with CD137 mAb.
Antibodies, Monoclonal ; immunology ; pharmacology ; HL-60 Cells ; Humans ; Lymphocyte Activation ; drug effects ; Lymphocyte Culture Test, Mixed ; T-Lymphocytes ; drug effects ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; immunology ; pharmacology

The generation of T cells with maximal anti-tumor activities will significantly impact the field of T-cell-based adoptive immunotherapy. In this report, we found that OKT3/IL-2-stimulated T cells were phenotypically more heterogeneous, with enhanced anti-tumor activity in vitro and when locally administered in a solid tumor mouse model. To further improve the OKT3/IL-2-based T cell manufacturing procedure, we developed a novel T cell stimulation and expansion method in which peripheral blood mononuclear cells were electroporated with mRNA encoding a chimeric membrane protein consisting of a single-chain variable fragment against CD3 and the intracellular domains of CD28 and 4-1BB (OKT3-28BB). The expanded T cells were phenotypically and functionally similar to T cells expanded by OKT3/IL-2. Moreover, co-electroporation of CD86 and 4-1BBL could further change the phenotype and enhance the in vivo anti-tumor activity. Although T cells expanded by the co-electroporation of OKT3-28BB with CD86 and 4-1BBL showed an increased central memory phenotype, the T cells still maintained tumor lytic activities as potent as those of OKT3/IL-2 or OKT3-28BB-stimulated T cells. In different tumor mouse models, T cells expanded by OKT3-28BB RNA electroporation showed anti-tumor activities superior to those of OKT3/IL-2 T cells. Hence, T cells with both a less differentiated phenotype and potent tumor killing ability can be generated by RNA electroporation, and this T cell manufacturing procedure can be further optimized by simply co-delivering other splices of RNA, thus providing a simple and cost-effective method for generating high-quality T cells for adoptive immunotherapy.
Animals ; CD28 Antigens ; genetics ; immunology ; Electroporation ; Humans ; Immunity, Cellular ; Interleukin-2 ; immunology ; K562 Cells ; Mice ; Muromonab-CD3 ; immunology ; Neoplasms, Experimental ; genetics ; immunology ; pathology ; RNA, Messenger ; genetics ; immunology ; T-Lymphocytes ; immunology ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; genetics ; immunology

OBJECTIVETo explore the in vitro effect on control of graft-versus-host disease (GVHD) and its mechanism in mice by blockade of CD137-CD137L pathway.

METHODSResponder spleen cells from BALB/c donor mice (H-2(d)) were incubated with stimulator spleen cells from C57BL/6 ( H-2(b)) recipient mice, with or without anti-CD137L mAb. Lethally irradiated C57BL/6 mice were transplanted with donor bone marrow cells plus primary MLC spleen T cells. Group A (Allo-BMT control group): allo-BMT mice not receiving any prevention measures for GVHD. Group B (CsA + MTX control group): CsA and MTX given to C57BL/6 mice after transplantation. Group C (experimental group): donor spleen cells from BALB/c mice treated with anti-CD137L mAb. The percentages of CD3+ CD8+ T and CD3+ CD4+ T cells in the three groups were detected by flow cytometry, and the level of cytokines (IFN-gamma, IL-2, IL-10, IL-4) by RT-PCR.

RESULTSThe incidence of GVHD in group C was 70%, while in group A and group B were 100%. The survival rate was higher and the median survival time was longer of group C than that of group A and B (P < 0.01). All mice in group A died of aGVHD within 15 ds, while 30% of mice in group C survived more than 30 ds. Symptoms and histological signs of GVHD in group C were the mildest among the three groups. The percentage of CD3+ CD8+ T cells and the levels of IFN-gamma were significantly lower (P < 0.01), and the levels of IL-10 were significantly higher in group C than those in group A and B (P < 0.01).

CONCLUSIONTreatment of donor T cells with anti-CD137L mAb in vitro may relieve GVHD, thereby improve the survival time and survival rate, which maybe related to increasing Th1 cytokine (IFN-gamma) and decreasing Th2 cytokine (IL-10) as well as reducing CD3+ CD8+ T cells.

4-1BB Ligand ; immunology ; Animals ; Antibodies, Monoclonal ; immunology ; pharmacology ; Bone Marrow Transplantation ; immunology ; Disease Models, Animal ; Female ; Graft vs Host Disease ; immunology ; prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Transplantation, Homologous ; immunology ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; immunology

4-1BB, a transmembrane molecule, member of the tumor necrosis factor receptor superfamily, is an important costimulatory molecule in the immune response, plays a key role in the clonal expansion and survival of CD8(+)T cells. In this study, we investigated 4-1BB regulation of CD4(+)T cell responses using 4-1BB transgenic (TG) mice that constitutively expressed 4-1BB on mature T cells. We first showed that CD4(+)T cells of 4-1BB TG mice had more sustained proliferative capacity in response to TCR/4-1BB stimulation in vitro compared to WT mice. Secondly, 4-1BB TG mice exhibited a more elevated contact hypersensitivity (CHS) response mediated by CD4+ Th1 cells due to more vigorous expansion of and apoptotic inhibition of CD4(+)T cells. Finally, CD4(+)T cells of 4-1BB TG mice had a heightened capacity for T cell priming. Overall, our results demonstrate the involvement of 4-1BB in CD4(+)Th1 cell responses by regulating the clonal expansion and survival of CD4(+)T cells as seen in CD8(+)T cells.
Animals ; Antibodies/immunology ; Antigens, CD ; Antigens, CD137 ; CD4-Positive T-Lymphocytes/cytology/*immunology/*metabolism ; Cell Division ; Cell Lineage ; Dermatitis, Contact/genetics/immunology ; Flow Cytometry ; Gene Expression ; Mice ; Mice, Transgenic ; Receptors, Nerve Growth Factor/*genetics/*metabolism ; Receptors, Tumor Necrosis Factor/*genetics/*metabolism

4-1BB, a member of the tumor necrosis factor receptor (TNFR) superfamily, is a major costimulatory receptor that is rapidly expressed on the surface of CD4+ and CD8+ T cells after antigen- or mitogen-induced activation. The interaction of 4-1BB with 4-1BBL regulates immunity and promotes the survival and expansion of activated T cells. In this study, the expression of 4-1BB and 4-1BBL was examined during regeneration of the murine thymus following acute cyclophosphamide-induced involution. Four-color flow cytometry showed that 4-1BB and 4-1BBL were present in the normal thymus and were preferentially expressed in the regenerating thymus, mainly in CD4+CD8+ double-positive (DP) thymocytes. Furthermore, the CD4loCD8lo, CD4+CD8lo and CD4loCD8+ thymocyte subsets, representing stages of thymocyte differentiation intermediate between DP and single-positive (SP) thymocytes, also expressed 4-1BB and 4-1BBL during thymus regeneration but to a lesser degree. Interestingly, the 4-1BB and 4-1BBL positive cells among the CD4+CD8+ DP thymocytes present during thymus regeneration were TCR(hi) and CD69+ unlike the corresponding controls. Moreover, the 4-1BB and 4-1BBL positive cells among the intermediate subsets present during thymus regeneration also exhibited TCRhi/int and CD69+/int phenotypes, indicating that 4-1BB and 4-1BBL are predominantly expressed by the positively selected population of the CD4+CD8+ DP and the intermediate thymocytes during thymus regeneration. RT-PCR and Western blot analyses confirmed the presence and elevated levels of 4-1BB and 4-1BBL mRNA and protein in thymocytes during thymus regeneration. We also found that the interaction of 4-1BB with 4-1BBL promoted thymocyte adhesion to thymic epithelial cells. Our results suggest that 4-1BB and 4-1BBL participate in T lymphopoiesis associated with positive selection during recovery from acute thymic involution.
4-1BB Ligand/genetics/*metabolism ; Animals ; Antigens, CD137/genetics/*metabolism ; CD4-Positive T-Lymphocytes/cytology/metabolism ; CD8-Positive T-Lymphocytes/cytology/metabolism ; Cell Adhesion ; Cell Differentiation ; Cell Line ; Cells, Cultured ; Cyclophosphamide/pharmacology ; Epithelial Cells/cytology ; Gene Expression Regulation ; Immunosuppressive Agents/pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; RNA, Messenger/genetics ; *Regeneration ; T-Lymphocytes/*cytology/metabolism ; Thymus Gland/*cytology/drug effects/*physiology