OBJECTIVE: To investigate the effect of signals mediated by activated CD28 in promoting survival of multiple myeloma (MM) cells and metabolic fitness and its possible mechanism. METHODS: The expression of CD28 on 4 MM cell lines (XG2, XG1, RPMI 8226 and U266) was determined by flow cytometry. Two cell lines with the highest or lowest CD28 expression were selected. The proliferation, cell cycle, migration and apoptosis of MM cells in vitro were determined in medium containing high glucose concentration or CD28 agonist monoclonal antibody with different bioassays. shRNA interference assay was used to knock down the expression of CD28 on U266 cells. Then, the effect of activated CD28 on glucose uptake rate and drug resistance in MM cells were analyzed using fluorescent glucose analogues (2-NBDG). The expression of Glut1/4, HkII and Fasn was determined with real time quantitative PCR. RESULTS: Flow cytometry analysis showed that all the four tested MM cell lines expressed CD28 and U266 cells had the highest positive rate. The results of in vitro experiment showed that CD28 activation could significantly up-regulate the expression of Glut4 and HkII, promote MM cell metabolic remodeling, enhance 2-NBDG/glucose uptake, increase energy metabolism, thereby elevating cell proliferation and migration abilities, leading to an increase in the number of cells in S- and G₂-phases. Meanwhile, activated CD28 subsequently up-regulated resistance of MM cells to bortezomib or dexamethasone. CONCLUSION MM cells express high levels of CD28 abnormally, and activation of CD28 can promote up-regulation of glucose uptake in MM cells, thereby promoting cell proliferation and enhancing drug resistance.
Humans ; Multiple Myeloma/pathology* ; CD28 Antigens/metabolism* ; Cell Proliferation ; Cell Line, Tumor ; Apoptosis ; Glucose/metabolism* ; Glucose Transporter Type 4/metabolism* ; Glucose Transporter Type 1

OBJECTIVE: To explore the role of DNAM-1 in the activation, proliferation and function of type Ⅰ regulatory T cells (Tr1 cells). METHODS: Anti-CD3/CD28 antibodies were used to stimulate mouse T cells derived from the spleen of wild-type (WT) mice, and the expression level of DNAM-1 in resting and activated Tr1 cells was evaluated with flow cytometry. Na?ve CD4⁺ T cells isolated by magnetic cell sorting from the spleens of WT mice and DNAM-1 knockout (KO) mice were cultured in Tr1 polarizing conditions for 3 days, after which CD25 and CD69 expressions were measured using flow cytometry. The induced Tr1 cells were labelled with CFSE and cultured in the presence of anti-CD/CD28 antibodies for 3 days, and their proliferative activity was analyzed. The expressions of IL-10 and p-STAT5 in DNAM-1-deficient Tr1 cells were detected before and after IL-2 stimulation. RESULTS: The expression level of DNAM-1 was significantly upregulated in CD4⁺ T cells and Tr1 cells after stimulation with anti-CD3/CD28 antibodies (P < 0.05). DNAM-1 knockout did not cause significant changes in the number or proportion of Tr1 cells, but but significantly increased the expression levels of the activation markers CD69 and CD25 (P < 0.05). Compared with WT Tr1 cells, DNAM-1-deficient Tr1 cells exhibited reduced proliferative activity in vitro (P < 0.05) with downregulated IL-10 production (P < 0.05) and decreased expressions of Il-10 and Gzmb mRNA (P < 0.05). In DNAM-1-deficient Tr1 cells, IL-2 stimulation significantly reduced IL-10 secretion level and the expression of p-STAT5 as compared with WT Tr1 cells. CONCLUSION DNAM-1 participate in the activation and proliferation of Tr1 cells and affect the biological functions of Tr1 cells through the IL-2/STAT5 pathway.
Animals ; Antigens, Differentiation, T-Lymphocyte ; CD28 Antigens/metabolism* ; Cell Proliferation ; Cells, Cultured ; Interleukin-10 ; Interleukin-2/metabolism* ; Mice ; RNA, Messenger ; STAT5 Transcription Factor/metabolism* ; T-Lymphocytes, Regulatory

Objective To identify and verify the distribution of Telocytes derived from heterogeneous interstitial cells in the vital organs of ApoE mice.Methods Heart,kidney,and liver tissues were harvested from ApoE adult mice. Immunohistochemical assays were performed by using different immunobiological markers.Results Telocytes were found in these vital organs. The expressions of immunobiological markers differed among different organs. CD34,CD117,and CD28 were positively expressed in Telocytes in cardiac tissue;CD117 and plateled-derived growth factor-Α were negatively expressed in Telocytes in renal tissue;and CD117 and plateled-derived growth factor receptor-Α had negative expression in Telocytes in hepatic tissue. Furthermore,the distribution of Telocytes also differed in the same organ.Conclusions Telocytes exist in the vital organs of ApoE mice,as demonstrated by immunohistochemisty assay. The expressions of immunobiological markers differ among Telocytes in different organs.
Animals ; Antigens, CD34 ; metabolism ; CD28 Antigens ; metabolism ; Kidney ; cytology ; Liver ; cytology ; Mice ; Mice, Knockout, ApoE ; Myocardium ; cytology ; Proto-Oncogene Proteins c-kit ; metabolism ; Telocytes ; cytology

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 investigate the correlation of the changes in CD8(+)CD28(-) T cell percentage with platelet (PLT) and D-dimer (D-D) levels in patients with multiple injuries (MI).

METHODSTwenty-six patients with MI, 31 with a single injury (SI group) and 26 healthy individuals were examined for peripheral blood CD8(+)CD28(-) T cells and intracellular transformation growth factor-β1 (TGF-β1) and interleukin 10 (IL-10) contents using flow cytometry at 24, 48, and 72 h after the injuries. PLT and D-dimer levels were compared among the 3 groups.

RESULTSCD8(+)CD28(-) T cells, TGF-β1 and IL-10 were significantly higher in MI group than in SI group and healthy control group (P<0.05) without significant differences between the latter 2 groups. The levels of PLT and D-D differed significantly among the 3 groups, the highest in MI group and the lowest in the control group. In MI group, CD8(+)CD28(-) T cells, TGF-β1 and IL-10 significantly increased at 48 h after the injury (P<0.05) but decreased significantly at 72 h (P<0.05) compared with the measurements at 24 h. The levels of PLT and D-D trended to decrease with time after the injuries and showed significant differences among the 3 groups at any of the 3 time points (P<0.05). CD8(+)CD28(-) T cells, TGF-β1 and IL-10 were all positively correlated with the levels of PLT and D-D in MI patients (r>0.70, P<0.05 for all comparisons).

CONCLUSIONIn MI patients, CD8(+)CD28(-) T cell percentage and their cytokines tend to increase early after the injury but decrease significantly at 72 h in close relation with the changes of the coagulation function following the injuries.

CD28 Antigens ; metabolism ; CD8 Antigens ; metabolism ; Case-Control Studies ; Fibrin Fibrinogen Degradation Products ; metabolism ; Flow Cytometry ; Humans ; Interleukin-10 ; metabolism ; Multiple Trauma ; immunology ; T-Lymphocyte Subsets ; cytology ; Transforming Growth Factor beta1 ; metabolism

This research was aimed to explore the effects of blocking B7/CD28 and CD40/CD154 co-stimulatory signals on engraftment of hematopoietic stem cell in the sensitized recipient so as to provide the experimental evidence for the treatment of sensitized recipient's immune rejection after clinical allogeneic hematopoietic stem cell transplantation (HSCT). The BALB/c mice were divided into 4 groups: (1)mice sensitized on 7 day before transplant; (2)mice were sensitized on 7 day before transplant, and injected CTLA4Ig+anti-CD154 applied; (3)normal mice injected by corresponding isotype control IgG of CTLA4Ig and anti-CD154; (4)normal blank control mice. Each group had 15 mice. On day 0, mice of each group were irradiated lethally 8 Gy by linear accelerator, and the bone marrow cells of C57BL/6 labeled by fluorescence staining were injected via the tail vein. The fluorescent cell level in peripheral blood and organ tissue at different time points were detected by flow cytometry (FCM) for homing assessment. Survival rates and hematopoietic reconstitution were also monitored and recorded. The results showed that application of CTLA4Ig anti-CD154 could promote implantation of allogeneic HSC in sensitized recipients, induce the immune tolerance, prolong their survival time and accelerate the hematopoietic reconstitution within 28 days, compared with the sensitized group. It is concluded that applying CTLA4Ig and anti-CD154 can enhance the engraftment of HSCT and induce immune tolerance in the sensitized recipient after allogeneic HSCT and accelerate the hematopoietic reconstitution.
Abatacept ; Animals ; B7 Antigens ; antagonists & inhibitors ; CD28 Antigens ; antagonists & inhibitors ; CD40 Antigens ; antagonists & inhibitors ; CD40 Ligand ; antagonists & inhibitors ; Graft Rejection ; prevention & control ; Hematopoietic Stem Cell Transplantation ; Immune Tolerance ; Immunoconjugates ; pharmacology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Transplantation, Homologous

This study was aimed to explore the effects of blocking B7/CD28 and CD40/CD154 co-stimulatory signals on immune function of sensitized mice', and provide the evidences of acquired immune tolerance for allogeneic bone marrow transplantation. The mice sensitized on 7 day before transplant were divided into 4 groups: (1)CTLA4Ig+ anti-CD154 isotype control IgG; (2)anti-CD154 +CTLA4Ig isotype control IgG; (3)CTLA4Ig and anti-CD154; (4)isotype control IgG of CTLA4Ig and anti-CD154. CTLA4Ig and anti-CD154 used in normal BALB/c mice as isotype control IgG. Each mouse in all groups received CTLA4Ig and anti-CD154 (or corresponding isotype control IgG) 500 µg respectively, and was injected via tail vein on 7 day before transplant. There were 5 mice in each group. The mice were sacrificed on day 0, then the number of CD19(+)CD69(+)B cells, CD44(high)/CD62L(high) and CD44(high)/CD62L(low)/- T cells were measured by flow cytometry. Changes of cytokines and sensitized antibody were tested by ELISA or flow cytometry. The results showed that the numbers of CD19(+)CD69(+)B cells were significantly increased in comparison with the normal group (P < 0.01) , whereas the numbers of cells were significantly decreased when blocking B7/CD28 or /and CD40/CD154 co-stimulatory signals (P < 0.01) . Blocking these 2 signals together displayed a synergistic effect (P < 0.01) . The central memory and effector T cells were defined as CD44(high)/CD62L(high) and CD44(high)/CD62L(low)/- respectively, those increased significantly after sensitized in comparison with those in normal group, whereas their numbers decreased when blocking B7/CD28 or/and CD40/CD154 co-stimulatory signals. Blocking these two signals together, displayed a synergistic effect (P < 0.01). Cytokines, IgG and IgM in all groups were not significantly different. Sensitizing antibody test showed that the fluorescence intensity of sensitized group significantly increased as compared with normal group, whereas fluorescence intensity of CTLA4Ig or/and anti-CD154 treated groups significantly decreased as compared with sensitized group (P < 0.01) . It is concluded that blocking the B7/CD28 or/and CD40/CD154 co-stimulatory signal can inhibit the cellular and humoral immune function, whereas blocking these two signals together displays a synergistic effect.
Animals ; B7-1 Antigen ; metabolism ; Bone Marrow Transplantation ; CD28 Antigens ; metabolism ; CD40 Antigens ; metabolism ; CD40 Ligand ; metabolism ; Immune Tolerance ; immunology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Signal Transduction ; Transplantation, Homologous

BACKGROUNDThe hygiene hypothesis has been proposed to explain the pathogenesis of asthma. Allergen exposure was shown to inhibit asthma in an animal model. But the optimal timing of allergen exposure remains unclear. This study aims to explore the time effcct of allergen exposure and the possible mechanisms.

METHODSNeonate Wistar rats were randomly divided into asthma group, control group and day 1, day 3, day 7, and day 14 groups. The day 1, day 3, day 7 and day 14 groups were injected with ovalbumin (OVA) subcutaneously on days 1, 3, 7 and 14 after birth, respectively. Six weeks later, all groups, except the control group, were sensitized and stimulated with OVA to make the asthma model. We observed the pulmonary pathologic changes, detected the regulatory T cells, and CD28 expression level in thymus and spleen by flow cytometry.

RESULTSThe asthmatic inflammation in the day 1, day 3 and day 7 groups, but not the day 14 group, was alleviated. The asthma group and day 14 group had lower proportions of regulatory T cells in the thymus compared with the control group, day 1, day 3, and day 7 groups. There was no significant difference in the CD28 expression levels on the regulatory and conventional T cells among groups. But the control group and the day 1, day 3, and day 7 groups had relatively higher proportions of CD28 positive regulatory T cells in the thymus than the day 14 group and the asthma group.

CONCLUSIONSThere is a "time-window" for early allergen exposure. The impairment of regulatory T cells may promote the development of asthma. Allergen exposure in the "time-window" can make the thymus produce normal quantity of regulatory cells. The CD28 signal on regulatory T cells may participate in the production of regulatory T cells.

Allergens ; immunology ; Animals ; Asthma ; etiology ; CD28 Antigens ; analysis ; physiology ; Disease Models, Animal ; Female ; Ovalbumin ; immunology ; Rats ; Rats, Wistar ; Signal Transduction

This study was purposed to investigate the molecular mechanism of 4-1BBL reverse signals in the human acute monocytic leukemia cell line of U937. The U937 cell line was used as target cells, and stimulated by the mouse anti-human 4-1BBL monoclonal antibody 1F1. The nuclear translocation of NF-κB and the co-location of 4-1BBL and CD28i molecules in U937 cells were observed with confocal laser scanning microscopy. The protein and m-RNA expression levels of 4-1BBL and CD28i were detected by flow cytometry and RT-PCR respectively. The results showed that the significant nuclear translocation of NF-κB and co-localization of 4-1BBL and CD28i on membrane of U937 cells appeared after being stimulated by mAb1F1. It is concluded that the 4-1BBL reverse signals transduction mediating the growth of U937 cells relates with the nuclear translocation of NF-κB. CD28i may be involved in intracellular 4-1BBL reverse signaling pathways.
4-1BB Ligand ; immunology ; metabolism ; Antibodies, Monoclonal ; pharmacology ; CD28 Antigens ; metabolism ; Coculture Techniques ; Humans ; NF-kappa B ; genetics ; Signal Transduction ; U937 Cells

OBJECTIVETo analyze the expression of co-stimulatory molecules PD-1/PD-L1 in peripheral blood mononuclear cells in lung cancer patients, and to explore its biological significance.

METHODSOne hundred and thirty-three lung cancer patients, 25 lung infection patients and 23 healthy donors were enrolled in this study. 100 µl of whole blood from these subjects were collected. Multi-color immunofluorescence staining and flow cytometry were used to detect PD-1/PD-L1 expression. The results were statistically analyzed.

RESULTSThe expression level of CD3⁺CD8⁺ T cells in the lung cancer patients was (38.83 ± 1.74)%, significantly lower than that in the control group [(43.25 ± 3.35)%, P < 0.05]. CD8⁺CD28⁺ T cell subset in the peripheral blood of lung cancer patients was (17.73 ± 1.21)% significantly lower than that of the healthy donors [(27.96 ± 2.72)%, P < 0.01]. The CD8⁺CD28⁻ T cell subset was (21.19 ± 1.92)% in the lung cancer patients, significantly higher than that of the healthy control group [(15.18 ± 2.93)%, P < 0.05]. The expression level of PD-1 on the surface of CD8⁺CD28⁺ T cells was (10.67 ± 1.12)% in the group of lung cancer patients, significantly higher than that of the control group [(5.32 ± 1.58)%, P < 0.01]. It was also found that the expression of PD-1 on CD8⁺CD28⁻ T cells was up-regulated in the group of lung cancer patients (7.46 ± 1.25)%, significantly higher than that of the healthy control group [(2.68+1.07)%, P < 0.01]. The expression level of PD-L1 on CD68⁺ cells in the lung cancer patients was (16.03 ± 2.06)%, significantly higher than that of the healthy control group [(9.32 ± 2.00)%, P < 0.05].

CONCLUSIONUp-regulation of PD-1/PD-L1 on peripheral blood cells in lung cancer patients negatively regulates the lymphocytes, inhibits the immune response for killing tumor cells, and promotes tumor development and immune escape.

Adenocarcinoma ; blood ; pathology ; B7-H1 Antigen ; metabolism ; CD28 Antigens ; metabolism ; CD3 Complex ; metabolism ; CD8 Antigens ; metabolism ; Carcinoma, Large Cell ; blood ; pathology ; Carcinoma, Squamous Cell ; blood ; pathology ; Case-Control Studies ; Female ; Humans ; Lung Neoplasms ; blood ; pathology ; Male ; Middle Aged ; Programmed Cell Death 1 Receptor ; metabolism ; Small Cell Lung Carcinoma ; blood ; pathology ; T-Lymphocytes ; immunology ; metabolism ; Up-Regulation