Construction of CAR-T cells targeting CS1 and analysis of their antitumor activity in vitro / 生物工程学报

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.

Inducible T-cell co-stimulators regulate the proliferation and invasion of human hepatocellular carcinoma HepG2 cells

Abstract Background This study determined the regulatory effects of inducible T-cell co-stimulators (ICOS) in human hepatocellular carcinoma HepG2 cells using a RNA interference (RNAi) technique. Methods A RNAi technique was used to knockdown the expression of ICOS. ICOS expression after knockdown was detected as mRNA and protein levels by RT-PCR and Western blot, respectively. A MTT colorimetric assay was used to detect cell proliferation, and the Transwell assay was used to detect cell invasion. Western blot was carried out to detect the level of Bcl-2, AKT, and PI3K protein expression in different groups. Results The proliferation of HepG2 cells were significantly decreased after ICOS siRNA transfection (EG group). Similarly, the results of the Transwell experiment showed that invasion of HepG2 cells in the EG group was clearly reduced compared to the negative control (NC) and blank control groups (CON). Western blot analysis showed that knockdown of ICOS expression reduced the levels of Bcl-2 and AKT, and also significantly up-regulated the level of PI3K phosphorylation (P < 0.01). Conclusion Down-regulating ICOS expression in HepG2 cells suppressed cell proliferation and invasion. The underlying mechanism may be related to the expression of the downstream factor, PI3K/AKT.

Phenotypic Tfh development promoted by CXCR5-controlled re-localization and IL-6 from radiation-resistant cells

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.

CD4[+] Foxp3[+] Treg and its ICOS[+] subsets in patients with myocardial infarction

Atherosclerosis is a multifactorial disorder with chronic inflammatory conditions in which immune cells play a significant role in its pathogenic process. Regulatory T cells [Treg], as a part of immune system, are involved in controlling autoimmune and inflammatory diseases. Quantitative and/or functional alteration of Tregs has been shown to play an atheroprotective role and may also promote plaque stabilization. To assess if inducible costimulatory molecule [ICOS] expression on one subtype of Treg cells with high suppressive potential correlates with the pathogenesis of atherosclerosis. Patients with myocardial infarction [MI] and/or stable angina [SA], diagnosed as atherosclerosis by angiography, and a group of individuals with normal coronary angiography [NCA] were recruited for the present study. Peripheral blood mononuclear cells [PBMCs] were prepared and the expression of ICOS, Foxp3 and CD4 molecules was tested by flowcytometry. The percentage of CD4[+] Foxp3[+] Treg cells was reduced in MI group compared to NCA and SA groups [p<0.005]. Evaluation of the two Treg subsets according to ICOS expression showed a decreased ICOS[+]/ICOS[-] Treg ratio in MI and SA groups compared to NCA individuals [p=0.002 and p=0.048, respectivly]. The present data indicate that Tregs and its ICOS[+] subsets are decreased in patients with MI or SA, suggesting a potential role for Treg in atherosclerosis progression or onset of acute coronary syndrome

Repressor of GATA-3 can negatively regulate the expression of T cell cytokines through modulation on inducible costimulator / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The 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.</p><p><b>METHODS</b>Real-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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSION</b>It 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.</p>

Expression of co-stimulators in ulcerative colitis and its pathologic significance / 中华病理学杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Expression 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.</p><p><b>RESULTS</b>In 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).</p><p><b>CONCLUSIONS</b>In 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.</p>

Blocking ICOS-B7h signal pathway by ICOS-Ig fusion protein inhibits function of allogeneic T lymphocytes / 中国实验血液学杂志

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.

Effect of anti-ICOS monoclonal antibody combined with low-dose CsA on chronic rejection of heart grafts in rats / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the effect of anti-inducible costimulator monoclonal antibody (anti-ICOS-Ab) combined with low-dose cyclosporine (CsA) on the survival quality and chronic rejection of heart allografts in rats.@*METHODS@#The rats' heterotopic cardiac transplantation model was established by Ono's method. The recipient rats were randomly divided into an isotransplantation control group and an allotransplantation experiment group. The experiment group was re-classified into a placebo group, a normal-dose CsA group, an anti-ICOS-Ab group, a low-dose CsA group, and an anti-ICOS-Ab combined with low-dose CsA group. The survival time of grafts was monitored. The cardiac grafts were harvested for histological analysis. Flow cytometric analysis was employed to detect the population of CD25+CD4+ in peripheral lymphocytes from recipients with a long-term surviving graft.@*RESULTS@#The survival time of the cardiac allografts in CsA-treated groups was significantly longer than that in placebo group (P0.05). Compared with the normal-dose CsA group, the chronic rejection lesions of the anti-ICOS-Ab combined with low-dose CsA treatment group significantly were alleviated in the long-term survival grafts, and the proportion of CD4+CD25+ regulatory T cell increased in peripheral blood.@*CONCLUSION@#The anti-ICOS-Ab combined with low-dose CsA can prolong the survival of cardiac allografts and alleviate the chronic rejection significantly. The high expression level of CD4+CD25+ regulatory T cell is beneficial to the long-term survival of grafts.

Study of reduction rat T-lymphocytes activation and proliferation by inhibition inducible co-stimulator gene expression / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the change of activation and proliferation ability of rat T-lymphocytes after suppress ICOS gene expression by RNA interference.</p><p><b>METHODS</b>Four 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.</p><p><b>RESULTS</b>After 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.</p><p><b>CONCLUSIONS</b>RNA interference plasmid vector can suppress ICOS expression in rat T-lymphocytes significantly, and it may be useful for further study on transplantation immunity tolerance.</p>

Effects of adenovirus-mediated gene transfer of ICOSIg fusion protein on experimental autoimmune myocarditis in Lewis rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the effects of adenovirus vector-mediated gene transfer of ICOSIg fusion protein on experimental autoimmune myocarditis (EAM) in Lewis rats.</p><p><b>METHODS</b>Expression vector containing ICOSIg (p-Adeno-ICOSIg) was constructed by fusion of human ICOS and IgGFc segment. Adenovirus vector was digested by PacI enzyme and transfected into HEK 293 cells. Adenovirus expressing ICOSIg was produced. EGFP was constructed into adenovirus vector and used as control. EAM was induced in Lewis rats by injection of porcine cardiac myosin. All immunized Lewis rats were divided into 4 groups. Group A (n = 15) and B (n = 15) received adenovirus containing ICOSIg on day 0 and day 14 respectively to study the effects of costimulatory molecules gene therapy on T cell activation and inflammation; group C (n = 10) and group D (n = 10) received adenovirus containing EGFP on day 0 and day 14 respectively as controls. Group E (n = 10) was normal controls that did not receive immunization. On day 28, all rats were killed after echocardiography examination. Histopathological examination was performed to observe myocardial inflammation. Protein levels of ICOS, ICOSL, B7-1 and B7-2 were detected by Western blot. INF-gamma, IL-2 and IL-4 mRNA were determined by realtime RT-PCR.</p><p><b>RESULTS</b>On day 28, cardiac function was significantly improved and myocardial inflammation significantly attenuated in group B compared to group A, C and D (all P < 0.05). B7-1 expression at protein level was significantly lower in group B than that of group C (P < 0.05). ICOS and ICOSL expressions at protein level were significantly decreased in both group A and B compared with group C and D (P < 0.05). IFN-gamma mRNA level significantly decreased and IL-4 mRNA significantly increased in group A and B compared to group C and D (P < 0.05).</p><p><b>CONCLUSIONS</b>Blockade of costimulatory pathway with gene therapy of ICOSIg alleviated autoimmune inflammatory damage and improved cardiac function in Lewis rats with EAM. Down-regulated costimulatory molecules in the myocardium and reduced inflammatory cytokine secretion might be responsible for the beneficial effects of ICOSIg in this model.</p>

Role of costimulatory signals in idiopathic thrombocytopenia purpura: review / 中国实验血液学杂志

Idiopathic thrombocytopenia purpura (ITP) is an autoimmune disease which is characterized by destruction of platelets by macrophages in the reticuloendothelial system. Recent studies suggest that ITP is related to the abnormal activation and apoptosis of T/B cells which lead to failure of immune tolerance. Now it is becoming clear that costimulatory signals are required for full T/B cell activation and assumed to modulate T/B cells responses as well as other aspects of the immune system. This review focuses on the role and state-of-the-art advancements of costimulatory signals in ITP.