OBJECTIVE: To investigate the expression of programmed death receptor-1 (PD-1) and inducible costimulator (ICOS) on the surface of CD8⁺ T cells in peripheral blood of patients with primary immune thrombocytopenia (ITP), and explore the roles of PD-1 and ICOS in the occurrence and development of ITP. METHODS: A total of 28 ITP patients treated in Tianjin Medical University General Hospital from September to December 2020 were selected, including 13 patients with newly diagnosed ITP, 15 patients with chronic ITP, and 22 healthy volunteers were recruited as control group. Flow cytometry was used to detect the expression levels of PD-1 and ICOS, and evaluate their correlation with clinical indicators. RESULTS: The percentage of CD8 ⁺ T cells in ITP patients of chronic group was higher than that of the newly diagnosed group and the control group (P<0.05). The expression level of PD-1 on CD8⁺ T cells in ITP patients of newly diagnosed group and chronic group were significantly lower than that of the control group (P<0.05), while the expression level of ICOS were significantly higher (P<0.05). In ITP patients, PD-1 was negatively correlated with platelet count (r=-0.4942, P<0.01), but positively with ICOS (r=0.4342). PD-1 and ICOS were both negatively correlated with lymphocyte count (r_PD-1=-0.4374; r_ICOS=-0.4492). CONCLUSION In ITP patients, the unbalanced expression of PD-1 and ICOS may interfere with the immune homeostasis of the body, which can be used as a therapeutic target for ITP patients.
CD8-Positive T-Lymphocytes/metabolism* ; Flow Cytometry ; Humans ; Inducible T-Cell Co-Stimulator Protein/metabolism* ; Platelet Count ; Programmed Cell Death 1 Receptor/metabolism* ; Purpura, Thrombocytopenic, Idiopathic

OBJECTIVETo observe the change of activation and proliferation ability of rat T-lymphocytes after suppress ICOS gene expression by RNA interference.

METHODSFour interference sites targeting at rat ICOS gene were designed and four pairs of oligonucleotide fragments were cloned into the pSilencer 4.1-CMV neo plasmid vectors then transfected into rat lymphocytes with cationic liposome. The expression of mRNA and protein of ICOS was detected by RT-PCR and flow cytometry. The alteration of lymphocyte proliferation ability was evaluated by mix lymphocyte reaction, and the secretion levels of IFN-gamma and IL-4 were measured by ELISA procedure.

RESULTSAfter transfection, the expression of mRNA and protein of ICOS in test groups were lower than that in control groups (P < 0.05). The ability of T-lymphocytes in proliferation was poor and the levels of IFN-gamma and IL-4 were reduced with ICOS gene shut down.

CONCLUSIONSRNA interference plasmid vector can suppress ICOS expression in rat T-lymphocytes significantly, and it may be useful for further study on transplantation immunity tolerance.

Animals ; Antigens, Differentiation, T-Lymphocyte ; genetics ; metabolism ; Cell Proliferation ; Cells, Cultured ; Female ; Genetic Vectors ; Inducible T-Cell Co-Stimulator Protein ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lymphocyte Activation ; Male ; RNA Interference ; Rats ; Rats, Sprague-Dawley ; T-Lymphocytes ; immunology ; metabolism ; Transfection

How follicular T-helper (Tfh) cells develop is incompletely understood. We find that, upon antigen exposure in vivo, both naïve and antigen-experienced T cells sequentially upregulate CXCR5 and Bcl6 within the first 24 h, relocate to the T-B border, and give rise to phenotypic Bcl6(+)CXCR5(+) Tfh cells before the first cell division. CXCR5 upregulation is more dependent on ICOS costimulation than that of Bcl6, and early Bcl6 induction requires T-cell expression of CXCR5 and, presumably, relocation toward the follicle. This early and rapid upregulation of CXCR5 and Bcl6 depends on IL-6 produced by radiation-resistant cells. These results suggest that a Bcl6(hi)CXCR5(hi) phenotype does not automatically define a Tfh lineage but might reflect a state of antigen exposure and non-commitment to terminal effector fates and that niches in the T-B border and/or the follicle are important for optimal Bcl6 induction and maintenance.
Animals ; CD40 Ligand ; metabolism ; Cell Differentiation ; physiology ; DNA-Binding Proteins ; metabolism ; Inducible T-Cell Co-Stimulator Protein ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Proto-Oncogene Proteins c-bcl-6 ; Receptors, CXCR5 ; metabolism ; T-Lymphocytes, Helper-Inducer ; metabolism

We constructed the CS1-targeted second- and third-generation CAR-T cells with genetic engineered 4-1BB or/and ICOS as a costimulatory signaling molecule by use of lentiviral platform. The CS1-targeted second-generation CAR-T cells with ICOS or 4-1BB had similar anti-neoplastic activity. When effector/target ratio was 1:1, the CAR-T cells with ICOS showed better killing effect on IM9-lucgfp cells than those with 4-1BB. However, The CS1-targeted third-generation CAR-T cells exihibited lower cytolytic capacity against IM9-lucgfp cells than the CS1-targeted second-generation CAR-T cells when the ratio of effector/target was 1:1, 2:1 or 5:1. When the ratio of effector/target was 10:1, the killing efficacy of both the second- and third-generation CAR-T cells against IM9-lucgfp cells was more than 85%, significantly higher than that of the control T cells. Taken together, both the CS1-targeted second- and third-generation CAR-T cells with ICOS or/and 4-1BB could efficiently kill CS1-positive multiple myeloma cells, but the CS1-targeted second-generation CAR-T cells had more potent killing effect on CS1-positive multiple myeloma cells than the CS1-targeted third-generation CAR-T cells.
4-1BB Ligand/metabolism* ; Cell Line, Tumor ; Genetic Engineering ; Humans ; Inducible T-Cell Co-Stimulator Protein/metabolism* ; Multiple Myeloma/therapy* ; Signal Transduction ; T-Lymphocytes/chemistry* ; Xenograft Model Antitumor Assays

Inducible costimulatory molecule (ICOS), a CD28 family member expressed on activated T cells, plays an important roles in T cell activation and effector function. This study was purposed to investigate the effect of blocking ICOS-B7h signal pathway by ICOS-Ig fusion protein on allogeneic reactive T cells and its mechanism. CHO cells stably and highly expressing ICOS-Ig were established, while the human ICOS-Ig fusion protein was harvested and purified from supernatant of CHO cells transfected with pSecTag2/Hygro A-ICOS-Ig. The CD4(+) cells from spleen of C57BL/6 mice were used as reactive cells, the bone marrow derived dendritic cells (DCs) from BALB/C mice were used as stimulatory cells, these cells were treated with different concentrations of ICOS-Ig or human Ig (h-Ig) as control. The results showed that the target protein with molecular weigh 54 kD and endotoxin level < 10 EU/ml was gained. The ICOS-Ig (> or = 10 microg/ml) could significantly inhibited the proliferative effect of allogeneic reactive T cells resulting from stimulation of DCs (p < 0.01). ICOS-Ig did not influence the activation of CD4(+) T cells. ICOS-Ig concentration positively related to the apoptosis of CD4(+) T cells. The percentages of CD4(+) Annexin V(+)PI(-) cells in simple stimulated group, ICOS-Ig 10 microg/ml group and ICOS-Ig 20 microg/ml group were 15.1%, 26.4% and 33.6% respectively. ICOS-Ig decreased secretion of TNFalpha and increased secretion of IL-4. It is concluded that the ICOS-Ig fusion protein has bioactivity of inhibiting T cell proliferation and altering the polarization of T helper cells to Th2 cells which promotes the apoptosis of allogeneic reactive T cells but had no effect on the activation of allo-reactive CD4(+) T cells.
Animals ; Antigens, Differentiation, T-Lymphocyte ; pharmacology ; Apoptosis ; drug effects ; CD4-Positive T-Lymphocytes ; drug effects ; immunology ; metabolism ; CHO Cells ; Cell Proliferation ; drug effects ; Cricetinae ; Cricetulus ; Inducible T-Cell Co-Stimulator Protein ; Interleukin-4 ; secretion ; Lymphocyte Activation ; immunology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Recombinant Fusion Proteins ; pharmacology ; Signal Transduction ; Th1 Cells ; drug effects ; immunology ; metabolism ; Th2 Cells ; drug effects ; immunology ; metabolism

OBJECTIVETo study the expression and localization of co-stimulators in the mucosa of patients with ulcerative colitis (UC), and to explore its role in the pathogenesis of UC.

METHODSExpression of co-stimulators CD86 and inducible co-stimulator (ICOS) was studied by immunohistochemistry on paraffin-embedded mucosal tissue from patients with active UC (64 cases), inactive UC (51 cases) and normal controls (20 cases). Immunostaining for CD28 was also carried out on frozen fresh mucosal tissue sampled from patients with active UC (7 cases), inactive UC (2 cases) and normal controls (5 cases). In addition, expression of CD4, CD8 and CD20 were also examined.

RESULTSIn active UC, increased expression of CD86 was not only observed in lamina propria mononuclear cells but also in the intestinal epithelial cells, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in lamina propria mononuclear cells was detected in active UC, as compared with inactive UC and the normal controls (P < 0.01). Increased ICOS expression in intestinal epithelial cells was also seen in active UC, as compared with that of inactive UC (P < 0.01). The expression of CD86 was higher in inactive UC than in the normal controls (P < 0.05 or P < 0.01). However, the expression of ICOS showed no statistically significant difference between inactive UC and normal controls. Increased expression of CD28 in active UC, compared with that in inactive UC and normal controls, was also noticed (P < 0.05 or P < 0.01). The number of CD4 or CD8-positive intraepithelial lymphocytes and lymphocytes infiltrating in the lamina propria and small vessel walls was much higher in active UC than in inactive UC and normal controls (P < 0.01). Moreover, the ratio of CD4/CD8 was highest in active UC (P < 0.01). The number of CD20-positive B lymphocytes in lamina propria was also higher in active UC than in inactive UC and normal controls (P < 0.01).

CONCLUSIONSIn active UC, CD86 and ICOS were over-expressed in the intestinal epithelial cells and lamina propria mononuclear cells. The phenomenon suggests that abnormal expression of co-stimulators may contribute to the deregulation of acquired immune responses in UC.

Adult ; Aged ; Antigens, Differentiation, T-Lymphocyte ; metabolism ; B7-2 Antigen ; metabolism ; CD28 Antigens ; metabolism ; CD4-CD8 Ratio ; Case-Control Studies ; Colitis, Ulcerative ; metabolism ; pathology ; Epithelial Cells ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Inducible T-Cell Co-Stimulator Protein ; Intestinal Mucosa ; metabolism ; pathology ; Leukocytes, Mononuclear ; metabolism ; pathology ; Male ; Middle Aged ; Mucous Membrane ; metabolism ; pathology ; Young Adult

BACKGROUNDThe transcription factor, repressor of GATA-3 (ROG), can simultaneously suppress the expression of T helper cells (Th1 and Th2) cytokines. Since the suppression of Th2 cytokines by GATA-3 is well understood, it is postulated that there are other molecular targets of ROG that can suppress the expression of the Th1 cytokines. We hypothesized that ROG might suppress the stimulators of T lymphocyte cytokines such as CD3, CD28, and inducible costimulator (ICOS), or indirectly enhance the expression of cytokine suppressors such as T lymphocyte-associated antigen-4 (CTLA-4) and CD45. The objective of this study was to clarify the molecular targets of ROG involved in suppressing Th1 or Th2 cytokines.

METHODSReal-time quantitative PCR (RT-PCR) and Western blotting were performed to evaluate the mRNA and protein levels of CD3, CD28, ICOS, CTLA-4, and CD45 in Th1 and Th2 cells during various levels of ROG expression. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of interferon-γ (IFN-γ) and interleukin (IL)-4 in culture media of Th1 and Th2 cells.

RESULTSThe results showed that the mRNA and protein levels of ROG were relatively low in Th1 and Th2 cells (P < 0.01). After ROG-pcDNA3.1 transfection, the mRNA and protein level of ROG was significantly elevated, while the expression of ICOS, IFN-γ, and IL-4 was markedly down-regulated (P < 0.01). Conversely, transfection of ROG-siRNA led to inhibition of ROG expression and up-regulation of ICOS, IFN-γ and IL-4 (P < 0.01). However, the expression levels of CD3, CD28, CTLA-4 and CD45 did not change in either ROG-pcDNA3.1 or ROG-siRNA-transfected Th1 and Th2 cells (P > 0.05).

CONCLUSIONIt is concluded that ROG can inhibit the expression of Th1 and Th2 cytokines by down-regulating the expression of ICOS, which might be a potential molecular target for asthma treatment.

Animals ; Blotting, Western ; CD28 Antigens ; metabolism ; CD3 Complex ; metabolism ; CD4-Positive T-Lymphocytes ; metabolism ; CTLA-4 Antigen ; metabolism ; Cells, Cultured ; Cytokines ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Inducible T-Cell Co-Stimulator Protein ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Leukocyte Common Antigens ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Real-Time Polymerase Chain Reaction ; Repressor Proteins ; genetics ; metabolism ; T-Lymphocytes ; metabolism ; Th1 Cells ; metabolism ; Th2 Cells ; metabolism