Orthogonal quantification of soluble inducible T-cell costimulator(ICOS)in healthy and diseased human serum / 药物分析学报

Inducible T-cell costimulator(ICOS),a homodimeric protein expressed on the surface of activated T-cells,is being investigated as a potential therapeutic target to treat various cancers.Recent studies have re-ported aberrant increases in the soluble form of ICOS(sICOS)in human serum in disease-state patients,primarily using commercial ELISA kits.However,results from our in-house immunoassay did not show these aberrant increases,leading us to speculate that commercial sICOS ELISAs may be prone to inter-ference.We directly tested that hypothesis and found that one widely used commercial kit yields false-positives and is prone to human anti-mouse antibody interference.We then analyzed a panel of healthy,cancer,chronic hepatitis C virus,systemic lupus erythematosus,and diffuse cutaneous systemic sclerosis human serum using our in-house immunoassay and reported the measured sICOS concentrations in these populations.Since even well characterized immunoassay methods are prone to non-specific interference,we also developed a novel sICOS LC-MS/MS method to confirm the results.Using these orthogonal approaches,we show that sICOS is a low abundance soluble protein that cannot be measured above approximately 20 pg/mL in human serum.

The functions of co-signaling molecules and their clinical applications in cancer therapy / 中国肿瘤生物治疗杂志

@#[摘 要] B7/CD28家族分子作为主要的共信号分子，在T细胞功能调控及免疫应答中发挥着至关重要的作用，关于其功能的研究及应用在世界范围内广泛开展。其中，CD28和CTLA-4都可以与B7-1/B7-2结合，但CD28能够促进T细胞增殖，维持Treg细胞稳态；而CTLA-4则可以抑制T细胞增殖，影响CD4+T细胞的分化；抗CTLA-4单抗ipilimumab与抗PD-1单抗联用能够用于治疗PD-L1+的非小细胞肺癌以及无症状的Ⅳ期黑色素瘤。PD-L1/PD-L2：PD-1途径则可以通过多种方式调节T细胞功能，参与CD8+T细胞“耗竭”状态的形成与维持。目前，针对PD-L1/PD-L2：PD-1途径的免疫治疗相关药物开发广泛且较为成熟，抗PD-1单抗主要通过诱导肿瘤浸润的部分耗竭的CD8+T细胞亚群的扩增发挥抗肿瘤作用。ICOS：ICOSL途径在T细胞分化、细胞因子分泌以及体液免疫应答中起着重要作用，抗ICOS抗体药物feladilimab与抗PD-1单抗联用能够有效治疗多发性或难治性骨髓瘤。B7-H3同时具有共刺激效应和共抑制效应，阻断B7-H3后能够有效增强TIL的抗肿瘤效应，其单抗enoblituzumab能够与抗PD-1单抗联用治疗非小细胞肺癌。B7-H4、人内源性逆转录病毒‑H长末端重复关联蛋白（human endogenous retrovirus‑H long terminal repeat‑associating protein，HHLA）以及含V结构域抑制T细胞活化的免疫球蛋白（V‑domain Ig‑cotaining suppressor of T cell activation，VISTA）均能够提供抑制信号，针对B7-H4靶点的CAR-T治疗以及VISTA的小分子抑制剂CA-170均有临床试验正在进行中。目前，对共信号分子的研究已经获得了长足进展，针对某些活化性分子或者抑制性分子开发了相关抗肿瘤药物并在临床中取得一定成效，但如何进一步提高其治疗有效率、减少不良反应等仍有待探索。

Relation between ICOS signaling and Th9 cell polarization in mice infected with Schistosoma japonicum / 中国血吸虫病防治杂志

To detect the expression level of ICOS on Th9 cells in mice infected with Schistosoma japonicum, and investigate the relation between ICOS signaling and Th9 cell polarization.Twenty-five mice with S. japonicum infection were used as models. IL-9+cells in CD4+ T cells and ICOS+ cells in Th9 cells of the mice were detected by flow cytometry 0, 4, 7, 9 weeks and 12 weeks after the infection.Compared with that 0 week after the infection, the proportion of Th9 cells in CD4+ T cells of the mice significantly increased 4, 7, 9, 12 weeks after the infection (all P < 0.05), and the proportion of ICOS+ cells in Th9 cells also markedly improved (P < 0.05).In S. japonicum infection, the ICOS signaling may have a regulatory effect on Th9 cell polarization.

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.

Role of ICOS on in-vitro cultured human PBMC Treg / 中国免疫学杂志

Objective:To investigate the role of mTOR in regulation of ICOS expression in human blood regulatory T cells. Methods:Isolation of Treg cells from human PBMC using MACS beads. We detected the ICOS expression on purified Treg cells and Treg cells viability using flow cytometry in anti-CD3 plus anti-CD28 ( antibody or beads) or anti-CD3 plus ICOSL-Fc for 3 days and 7 days. CFSE labeling human PBMC cells and in vitro cultured Treg mixed, Treg contact inhibition activity was detected by flow analysis. Results:After in vitro stimulation of Treg cells in the presence of anti-CD3+anti-CD28 for 3 days, there was no significant statistic difference in viability between ICOS+(92. 00±2. 69)% and ICOS-(90. 30±3. 53)% Treg-cells. After cultured for 7 days,the decreased ICOS+ Treg cells percentage within total Treg cells from ( 40. 20 ± 1. 83 )% to ( 11. 60 ± 1. 10 )% compared with that of 3 days. Further more,the ICOS expression level between stimulated with anti-CD28 or ICOSL-Fc condition group,compared with the ICOS MFI in the condition of anti-CD3 plus anti-CD28 treatment for 3 days was (2410. 0±746. 4) obviously higher than (403. 30±74. 42), that of the group treated with anti-CD3 plus ICOSL-FC. Rapamycin could partially suppress Treg cells ICOS expression,but unaffected the Treg suppression ability. Conclusion:ICOS expression level may not important for in vitro cultured human PBMC Treg cells survival although mTOR signling is important for regulation ICOS expression on in-vitro cultured Treg cells,but the ICOS expression on Treg regulated by multiply signaling pathways. CD28 signaling is the key stimulation factor for ICOS upregulation on in-vitro cultured Treg cells compared to ICOSL signaling.

Clinical significance of ICOS and ICOSL expression in patients with rheumatoid arthritis / 中国免疫学杂志

Objective:To investigate the expression of inducible costimulatory ( ICOS) and inducible costimulatory ligand ( ICOSL) on peripheral blood mononuclear cells ( PBMCs ) and their clinical relationship with rheumatoid arthritis ( RA ) patients.Methods:Peripheral blood samples were collected from 85 RA patients and 50 HC in this study.Expression of ICOS and ICOSL on PBMC from the subjects were detected by flow cytometry and real-time polymerase chain reaction( RT-PCR).The alteration of ICOS and ICOSL were observed after hormone therapy in 15 patients with RA and the relationship between their expression level and patients′clinical manifestations were analysed.Results:The ICOS and ICOSL mRNA level of RA patients′PBMCs were significantly higher than that in HC.The expression level of ICOS on CD4+T cells was higher than than that in HC[(7.08±4.72)% vs (3.01+1.39)%,P<0.0001].The expression of ICOSL on monocytes[(5.77±3.45)%vs (3.64±1.43)%,P<0.05] and B cells [(5.78± 4.52)%vs (3.97±1.63)%,P<0.05] were significantly elevated in RA patients.In RA patients with active disease,however,ICOSL expression on monocytes and B cells were increased as compared with those in inactive RA patients [ ( 5.45 ±3.50 )% vs ( 4.04 ± 1.55)%,P=0.036],[(6.59 ±5.74)%vs (5.63±4.30)%,P=0.016].Furthermore,after receiving immunosuppressive therapy, the expressions of ICOS and ICOSL were notably reduced as compared with pre-therapy levels on PBMCs from patients [ ( 5.45 ±3.50)%vs (4.04±1.55)%,P=0.036],[(6.59 ±5.74)%vs (5.63±4.30)%,P=0.016].Conclusion:The high levels of ICOS and ICOSL expression were closely correlated with the degree of disease and therapeutic response,suggesting that ICOS/ICOSL pathway may play a critical role in pathogenesis of RA.

Effect of inducible costmulator/inducible costmulator ligand signaling pathway on hepatic fibrosis in mice infected with Schistosoma japonicum / 中华传染病杂志

Objective To analyze the effect of inducible costmulator (ICOS)/inducible costmulator ligand (ICOSL) signaling pathway on hepatic fibrosis in mice infected with Schistosoma japonicum.Methods Seventy-eight ICOSL knockout (ICOSL-KO) mice and 77 wild type C57BL/6J mice were used as experimental schistosomiasis model infected with Schistosoma japonicum.The sera of mice were collected on the day before infection (0 week),and at 4,7,12,16 and 20 weeks post infection.Then,the concentrations of hyaluronic acid (HA) and hydroxyproline (HYP) in mice sera were measured by sandwich enzyme linked immunosorbent assay (ELISA) kits.The expressions of transforming growth factor β1 (TGF-β1),α-smooth muscle actin (a-SMA) and Collagen-Ⅰ in livers from ICOSL-KO/wild type mice were assessed by immunohistochemical staining.The granulomatous pathology and fibrosis level in mice liver were dynamically observed by hematoxylin and eosin (HE) staining and Masson's staining,respectively.The difference between groups was detected by t test or x2 test when appropriate.Results After infection with Schistosoma japonicum,the levels of HA and HYP were gradually increased.In ICOSL-KO mice,the levels of HA at 7,12,16 and 20 weeks post infection were all significantly lower than those in wild type mice [(161.32±15.44) vs (186.01±21.24) ng/mL,t=2.528 2,P＜0.05; (166.73±18.18) vs (231.39±20.12) ng/mL,t=4.342 4,P＜0.05; (193.58±21.06) vs (252.51±25.29) ng/mL,t=4.003 9,P＜0.05; (253.98±24.53) vs (310.88±23.86) ng/mL,t=3.718 0,P＜0.05].Similarly,HYP levels in ICOSL-KO mice at 12,16 and 20 weeks post infection were all significantly lower than those in wild type mice (all P＜0.05).Immunohistochemical staining showed that TGF-β1,α-SMA and Collagen-Ⅰ expressions in liver of ICOSL-KO mice from 7 to 20 weeks post infection were all significantly lower than those of wild type mice (all P＜0.05).HE staining showed,the volume of liver egg granulomas of ICOSL-KO mice was significantly smaller than that of wild type C57BL/6J mice (P＜0.01).Furthermore,Masson's staining showed that the level of hepatic fibrosis in ICOSL-KO mice was lower than that in wild type mice and the fibrosis scores were statistically different between two groups (all P＜0.05).The mortality rate of the wilde type C57BL/6J mice was higher than that of ICOSL-KO mice.After 20 weeks of infection,the difference was statistically significant (55.84 ％ vs 37.18 ％,x2 =5.427,P＜0.05).Conclusions The degree of hepatic fibrosis and related indicators are obviously down-regulated in ICOSL-KO mice infected with Schistosoma japonicum.These findings suggest that ICOS/ICOSL signaling pathway has an important impact on the process of hepatic fibrosis caused by Schistosoma japonicum.

Relationship between Co-expression Levels of ICOS and CD28 on Peripheral Blood CD4+ and CD8+ T Cells and Behcet’s Disease / 华中科技大学学报(医学版)

Objective To study the relationship between the co‐expression levels of inducible costimulatory molecule (ICOS)and CD28 on peripheral blood CD4+ and CD8+ T cells and Behcet’s disease(BD).Methods Flow cytometry was used to detect the expression levels of ICOS and CD28 on peripheral blood CD4+ and CD8+ T cells of BD patients(n=22) ,including those with active BD(ABD ,n= 14)and stable BD(SBD ,n= 8) ,and of normal subjects(n= 22).Results The proportion of CD28+ ICOS+ CD4+ T cells was significantly increased in ABD patients when compared with normal subjects [(34.72 ± 12.87)% vs.(25.36 ± 8.24)% ,P0.05]between the two groups.The proportions of CD28-ICOS+ CD4+ T cells and CD28-ICOS+CD8+ T cells were both obviously increased in ABD patients when compared with those in normal subjects[(2.54 ± 1.63)% vs.(0.76 ± 0.25)% for CD28- ICOS+ CD4+ T cells ,P< 0.05;(8.79 ± 3.41)% vs.(3.04 ± 1.25)% for CD28-ICOS+CD8+ T cells ,P<0.05].Conclusion The increased expression level of ICOS on peripheral blood CD4+ and CD8+ T cells is not closely associated with the expression of CD28 to some extent in BD patients ,suggesting that cells expressing only ICOS play an important role in the development of BD.

Changes of CD4 +CD25highFoxp3 +regulatory T cells and their significance in childhood B-cell acute lymphocytic leukemia / 中华微生物学和免疫学杂志

Objective To investigate the changes of CD4 +CD25highFoxp3 +regulatory T (Treg) cells and their significance in immune escape of childhood B-cell acute lymphocytic leukemia ( B-ALL ) . Methods Forty-two children with B-ALL and twenty-eight age-matched healthy children were enrolled in this study.Flow cytometry analysis was performed to evaluate the proportion of CD 4 +CD25high Foxp3 +Treg cells as well as CD4 +CD25high ICOS+Foxp3 +and CD4 +CD25high ICOS-Foxp3 +subsets in peripheral blood samples.The expression of associated molecules including IL-10, TGF-β, IL-35, TGF-βRII, ICOS and CD28 at protein level were also measured by flow cytometry analysis .The transcription level of Smad3/4, TIEG1 and Itch by CD4 +T cells were determined by quantitative real-time PCR.The concentration of TGF-βin plasma was detected by enzyme-linked immunosorbent assay.Results (1)The proportion of CD4 +CD25highFoxp3 +Treg cells in children with B-ALL were significantly higher than those of health subjects (P0.05).(3)The concentra-tion of TGF-βin plasma from children with B-ALL were higher than those from control group [ ( 25 .83 ± 12.65) ng/ml vs (8.59 ±5.73) ng/ml, P<0.05].The expression of TGF-βRII and its associated mole-cules (Smad3/4, TIEG1 and Itch) by CD4 +T cells were significantly up-regulated.Moreover, an increased expression of ICOS and CD28 by CD4 +CD25highFoxp3 +Treg cells were also observed in children with B-ALL (P<0.05).Conclusion The hyper-activity of TGF-β, ICOS and CD28 signaling might be closely associ-ated with the increased proportion of CD4 +CD25high Foxp3 +Treg cells and the imbalance of its subsets in children with B-ALL.

Asociación del polimorfismo del gen ICOS (c.1564 t/c) con hepatitis autoinmune tipo 1 en población mestiza venezolana / Association of icos (c.1564 T/C) gene poymorphims with autoimmune hepatitis type 1 in Venezuelan mestizo population)

Introducción: Un evento inmunopatológico característico en la hepatitis autoinmune (HAI) es la activación prolongada de la respuesta Th1. Diferentes promotores genéticos pueden predisponer a esta activación provocando ruptura de la inmunotolerancia. Uno de estos promotores es ICOS perteneciente a la familia de CD28, moléculas involucradas en funciones que regulan las respuestas Th1 y Th2 previniendo la activación prolongada de la respuesta Th1. Objetivo: Determinar el polimorfismo del gen ICOS (c.1564 T/C) en pacientes mestizos venezolanos con HAI tipo 1 y su posible asociación con la expresión clínica. Materiales y Métodos: Se investigaron 70 pacientes con HAI tipo 1 y 121 individuos sanos, ambos grupos venezolanos de tercera generación. La determinación del polimorfismo se realizó mediante reacción en cadena de la polimerasa (PCR) seguida por polimorfismos en la longitud de los fragmentos de restricción (RFLP). Resultados: El alelo silvestre T fue el más frecuente tanto en pacientes como en controles siendo mayor en el segundo grupo (60,7% vs 70,4%; p=0,05; pc=ns OR 1,45 p<0,05). El alelo mutado C se observó más en los pacientes con respecto al grupo control (39,3% vs 29,6%; p=0,05; pc=ns OR 1,45 (p<0,05). En las frecuencias genotípicas, se demostraron los genotipos heterocigotos (T/C) y homocigotos para el alelo mutado (C/C) más prevalentes en el grupo de pacientes que en controles y el genotipo silvestre T/T más frecuente en controles que en pacientes siendo estas diferencias significativas al 10% (χ2=5,31;2GL;p=0,07); OR 2,08 (p<0,05). Los pacientes con el genotipo heterocigoto demostraron niveles más elevados de globulinas, de IgG y mayor presencia de anticuerpos anti-mitocondriales que los observados en el genotipo T/T con diferencia estadística significativa al 10%. Además, se observa menor presencia de anticuerpos antinucleares en el genotipo T/C vs. T/T (p<0,10; pc=ns). Conclusiones: En el estudio del polimorfismo del gen ICOS (c.1564 T/C) los genotipos heterocigoto T/C y homocigoto mutado C/C son más frecuentes en pacientes mestizos venezolanos con HAI tipo 1 que en controles con riesgo significativo. Este polimorfismo se asocia a ciertas variables inmunodiagnósticas.

Introduction: A characteristic immunopathological event in autoinmune hepatitis (AIH) type 1 is the prolonged activation of Th1 response. Different promoters might predispose to this activation inducing immunotolerance breaking. ICOS is one of these promoters which belong to CD28 family, molecules involved in Th1 and Th2 regulating functions to prevent Th1 longer activation. Objective: To determine gen ICOS (c.1564 T/C) polymorphism in Venezuelan mestizo patients with AIH type 1 and its possible association with clinical expression. Materials and Methods: Seventy patients with AIH type 1 and 121 healthy individuals, both third generation Venezuelan groups, were investigated. Polymorphism determination was performed by polymerase chain reaction (PCR) following by restriction fragments longitudinal polymorphisms (RFLP). Results: The most frequent allele was wild T either in patients and controls, being higher in the second group (60,7% vs. 70,4%; p=0,05; pc=ns OR 1,45 p<0,05). The mutant C allele was observed more in patients than controls (39,3% vs. 29,6%; p=0,05; pc=ns OR 1,45 (p<0,05). In the genotypes frequencies, heterozygote genotypes (T/C) and homozygote mutant allele (C/C) were prevalent in the patient’s group while in the control´s group the wild genotype T/T was the most frequent being these differences significantly to 10% (χ2=5,31;2GL;p=0,07); OR 2,08 (p<0,05). Compared to the T/T genotype group, patients with heterozygote genotype shown higher levels of globulins, IgG and presence of anti-mithocondrial antibodies with a significant difference to 10%. Moreover, presence of antinuclear antibodies was less frequent in the T/C genotype vs. T/T (p<0,10; pc=ns). Conclusion: Heterozygote genotype T/C and homozygote mutant genotype C/C of gen ICOS (c.1564 T/C) with a significantly risk are more frequent in Venezuelan mestizo patients with AIH type 1 than in controls with a significantly risk. This polymorphism is associated with certain immunodiagnostic variables.

Immune response and immunopathology in ICOSL knockout mice infected with Schistosoma japonicum / 中国人兽共患病学报

To determine immune responses and immunopathology in ICOSL knockout (ICOSL KO) mice infected with Schistosoma japonicum,ICOSL- KO mice and wild-type C57BL/6J mice were used as experimental models for Schistosoma japonicum infection.The splenic lymphocytes were isolated from the mice the day before infection (0 week) as well as 4,7,12,16 and 20 weeks post infection,and stimulated with SEA for 72 hours in culture.The concentrations of Th1 cytokines (IFN-γand IL- 12) and Th2 cytokines (IL- 4,IL-10 and IL-13) in the culture supernatants were measured by sandwich ELISA.The levels of SEA-specific IgG antibody and its subtypes (IgG1 and IgG2a) were measured in mouse sera by ELISA.Pathological changes of hepatic granuloma in mice were determined by hematoxylin and eosin (H&E) staining.After the infection,the levels of Th1 cytokines,IFN- γ and IL 12,in ICOSL- KO mice were higher than those in wild-type C57BL/6J mice.However,the levels of Th2 cytokines (IL- 4,IL- 10 and IL- 13) were significantly decreased in ICOSL-KO mice compared to those in wild-type C57BL/6J mice.The levels of SEA-specific IgG antibody and its subtypes (IgG1 and IgG2a) in the sera of ICOSL- KO mice were also significantly lower than those of wild -type C57BL/6J mice.Moreover,the Th2 differentiation index was lower in ICOSL- KO mice than in wild-type C57BL/6J mice at 4,7,12,16 and 20 weeks post-infection.Similarly,the ratio of IgG1/IgG2a in ICOSL-KO mice was significantly lower than that in wild- type C57BL/6J mice at 7,12 and 16 weeks post- infection.Furthermore,throughout the course of disease progression,the volume of hepatic egg granuloma in ICOSL- KO mice was significantly smaller than that in wild-type C57BL/6J mice.In conclusions,there is a substantially down-regulated Th2 immune response in ICOSL- KO mice infected with Schistosoma japonicum,thus results in an attenuated hepatic lesion caused by egg granulomas.The findings indicate that the ICOS ICOSL co-stimulatory pathway plays an important role in the hepatic egg granuloma formation of schistosomiasis.

Application of molecular fingerprinting for analysis of a PAH-contaminated soil microbiota growing in the presence of complex PAHs / Aplicação de técnica molecular para análise da microbiota de solo contaminado em misturas complexas de HPAs

Polycyclic aromatic hydrocarbons (PAHs) constitute a group of priority pollutants which are present at high concentrations in the soils of many industrial contaminated sites. Pollution by these compounds may stimulate growth of organisms able to live in these environments causing changes in the structure of the microbial community due to some cooperative process of metabolization of toxic compounds. A long-term PAH-contaminated soil was stored for several years and used to analyze the native microbiota regarding their ability to grow on pyrene, benzo[a]pyrene, as well as in mixtures of LMW- and HMW-PAHs. Molecular profiles of the microbial community was assessed by PCR-DGGE of 16S rRNA gene, and the number of bands observed in DGGE analyses was interpreted as dominant microbial members into the bacterial community. Results of PAH-contaminated soil microorganisms showed different profiles in the degradative dynamics when some nutrients were added. Predominant species may play a significative role while growing and surviving on PAHs, and some other metabolically active species have emerged to interact themselves in a cooperative catabolism of PAHs.

Os hidrocarbonetos poliaromáticos (HPAs) são considerados poluentes prioritários presentes em expressiva concentração no solo contaminado com derivados de petróleo. A poluição por esses compostos estimula o crescimento de microrganismos capazes de sobreviverem nestes ambientes contaminados, causando alterações na estrutura da comunidade microbiana do solo pelo processo de cooperação metabólica entre as populações. Um solo contaminado por um longo período de tempo foi coletado de uma área industrial (Port Melbourne, Austrália) e utilizado para análise da capacidade da comunidade microbiana em crescer em HPAs isolados e/ou em misturas como únicas fontes de carbono e energia. Os perfis moleculares foram obtidos por PCR-DGGE do fragmento da subunidade 16S do DNA ribossomal, sendo o número de bandas presentes nos géis de eletroforese interpretado como populações dominantes dentro da comunidade do solo. Resultados demonstraram diferentes perfis quando vitaminas e micronutrientes fizeram parte do meio líquido de crescimento da microbiota, além da presença dos HPAs. As espécies predominantes podem ter papel significativo na degradação desses compostos no solo a ser remediado, enquanto sobrevivem e interagem com outras populações por meio de mecanismos de catabolismo cooperativo.

Eukaryotic expression of human ICOS-Ig fusion protein and analysis of its biological activity / 第二军医大学学报

Objective: To express human ICOS extracellular region and IgG Fc fusion protein using euckaryotic vector and to analyze its biological activity. Methods: Human ICOS extracellular region and IgG Fc fragment were cloned by RT-PCR and inserted into eukaryotic expression vector pSecTag2. The constructed plasmid pSecTag2-ICOS-Ig was stably transfected into CHO cells. Soluble ICOS-Ig fusion protein was collected from serum-free medium and purified with protein A affinity chromatography. The purified product was analyzed by SDS-PAGE, Western blotting assay, and ELISA. Fluorescence-activated cell sorting (FACS) and mixed lymphocyte reaction (MLR) were used to study the activity of the fusion protein. Results: ICOS extracellular region and IgG Fc fragment were successfully cloned into expression vector; ICOS-Ig fusion protein was expressed and purified in mammal cells. The purified fusion protein specifically bound to ICOSL and inhibited mixed lymphocyte reaction. Conclusion: A ICOS-Ig fusion protein expression system has been successfully constructed, and bioactive ICOS-Ig fusion protein has been obtained.

Physicochemical properties and biological activity of a recombinant inducible co-stimulator-Ig fusion protein / 第二军医大学学报

Objective: To investigate the physicochemical properties and biological activity of self-prepared fusion protein inducible co-stimulator-Ig. Methods: Acid hydrolysis, edman degradation and peptide mass finger printing were used to determine the amino acid composition, N-terminal 15 amino acid sequences, and peptide mapping. In vivo mixed lymphocyte reaction assay was used for identification of its biological activity. Results: The result of amino acids composition analysis was consistent with the theoretical value of ICOS-Ig. N-terminal 15 amino acid sequences of the product were EINGSANYEMFIFHN, consistent with the theoretical value of ICOS-Ig. Peptide match assay identified six peptides of the product which could match the theoretic maps of ICOS-Ig. ICOS-Ig and CsA noticeably inhibited the proliferation of allo-reactive T cells in vivo. Conclusion: The prepared ICOS-Ig fusion protein has a correct structure and can inhibit the proliferation of allogeneic T cells in vivo, which lays a foundation for quality control of ICOS-Ig fusion protein.

Distribution of CD4~+ CD25~+ FOXP3~+ regulatory T cells and their subsets in colorectal carcinoma and the clinical significance / 中国免疫学杂志

Objective: To determine the distribution of CD4~+CD25~+FOXP3~+regulatory T cells (Treg) and Treg subsets in human colorectal carcinoma microenvironment and to explore their correlation with conventional clinico-pathological features.Methods: Frozen sections and Immunohistochemistry (IHC) were used to detect FOXP3~+ Treg in flesh specimen collected from 42 patients with colorectal carcinoma.The number of FOXP3~+ Treg was evaluated in terms of its association with clinico-pathological feature in tumor and peri-cancer tissue.Double staining was performed to determine the expression of ICOS and FOXP~3.Results:The number of FOXP3~+ Treg in the colorectal carcinoma (mean 24.1) was significantly higher than that in peri-cancer tissue (mean 0.7).A higher number of tumor infiltrating FOXP3~+ Tregs was found in the patient groups with poor differentiation,lymphatic metastasis and non-distant metastasis as compared to the patient groups with well differentiation,non-lymphatic metastasis and distant metastasis.The percentage of FOXP3~+ ICOS~+ Treg was higher in colorectal carcinoma(81% ) than that in peri-cancer tissue(10% ).Condusion: Increased FOXP3~+ Treg may influence the occurrence and development of colorectal carcinoma.Our data support the hypothesis that tumor infiltrating FOXP3~+ Tregs attenuate the immune response against cancer and suggest that strategy to overcome FOXP3~+ Treg function may be beneficial in the treatment of human colorectal cancer.

Costimulatory molecules CD28-B7 family and clinical diseases / 国际儿科学杂志

The CD28-B7 are members of immunoglobulin superfamily.When B7 is engated by the CD28 ligand, a costimulatory signal occurs and transfers to T cell and it is important in the activation, proliferation, anti-apoptosis and promoting cytokine secretion of T cell.The CD28-B7 family is associated with tumor and autoimmune disease.

Eficiência de fungos micorrízicos arbusculares isolados de solos sob diferentes sistemas de uso na região do Alto Solimões na Amazônia

Arbuscular mycorrhizal fungi (AMF) are important components of terrestrial ecosystems where they are believed to play a fundamental role for their sustainability. These fungi are influenced by a number of anthropic factors such as, land use which modifies the structure and diversity of fungal communities and this may compromise their ecological functions. In the present study it was evaluated the behavior of AMF isolated from soils under different land use systems in (LUS). Fifty-one AMF were isolated in trap cultures from soil samples from different SUT tested on cowpea [Vigna unguiculata (L.) Walp] under controlled conditions. It was found that all AMF colonize the cowpea, but in a highly variable intensity. Similar results were found for phosphorus uptake and plant growth. Colonization ranged from 1 to 68%. Growth positive effects ranged from 33 to 148%, being more common in isolates from pasture and crops ecosystems. The enhancement in phosphorus uptake was generalized (95% all fungi), but their growth promoting effects did not followed the same trend. Only 39% of fungal isolated tested were efficient. These more isolated from almost all LUS. Fungal treatments with high efficiency had the following species: A. foveata, Glomus sp.1, Acaulospora sp.1 and a mixture the first two species with A. bireticulata and E. infrequens. The results indicate a wide efficiency diversity of AMF in the Alto Solimões region. Although this characteristic has no direct relationship with the LUS, the proportion of effective isolates varied with their origin.

Os fungos micorrízicos arbusculares (FMAs) são importantes componentes dos ecossistemas terrestres onde acredita-se desempenharem papel fundamental para a sustentabilidade destes. Estes fungos sofrem influência de diversos fatores antrópicos como o uso da terra, que modificam a estrutura e diversidade das comunidades podendo comprometer suas funções ecológicas. No presente estudo avaliou-se o comportamento de FMAs isolados de solos sob diferentes sistemas de uso (SUT). Fungos isolados de amostras de solo sob diferentes SUT foram testados em caupi [Vigna unguiculata (L.) Walp] em condições controladas. Verificou-se que todos os cinqüenta e um fungos avaliados colonizaram o caupi, porém de modo muito diferenciado, tal como ocorreu para os efeitos destes na absorção de fósforo e crescimento da planta. A colonização variou de 1 a 68%, e os efeitos positivos no crescimento variaram de 33 a 148%, sendo mais comuns nos fungos isolados de pastagem e roça. O aumento nos teores de fósforo foi generalizado (95% dos fungos testados), no entanto, nem todos foram capazes de promover o crescimento do Caupi. Apenas 39% dos fungos foram considerados eficientes, sendo estes isolados de quase todos os SUT. Os tratamentos fúngicos de mais alta eficiência continham as espécies: A. foveata, Glomus sp.1, Acaulospora sp.1 e mistura dos dois primeiros mais E. infrequens e A. bireticulata-like. Os resultados indicam ampla diversidade de eficiência dos FMAs do Alto Solimões. Embora a eficiência não tenha relação direta com o SUT, a proporção de isolados eficientes variou com a origem de isolamento.

Influence of dendritic cells modified with ICOS extracellular region on survival of renal allografts in rats / 重庆医科大学学报

Objective:To study the influence of donor dendritic cells (DCs) modified with ICOS extracellular region on the survival of renal allografts in rats. Methods:Bone marrow derived DCs of Brown Norway(BN) rats were modified with ICOS extracellular region gene recombined adenovirus and injected into Lewis rats 24 h before BN→Lewis kidney transplantation. Survival time of renal allografts was observed and one-way mixed splenic cell reaction (MSR) of the recipients to donors and the third party rats were performed by means of MTT on the 20th postoperative day. Results:Survival time of renal allografts was prolonged significantly [comparedwith control, (23.2?3.08) d vs(8.5?1.4) d,P

ICOS Regulate Survivin Expression and Sustain T Cell Survival / 生物化学与生物物理进展

To study whether the late-acting co-stimulatory molecules ICOS can suppress the apoptosis and sustain the survival and proliferation of T cells through the survivin pathway, ICOS signals deficient T-cells were infected with adenovirus carried survivin gene, other T-cells were given ICOS co-stimulatory signals, then infected with adenovirus carried dominant-negative mutant survivin gene. Apoptosis and proliferation were determined by TUNEL and CCK-8 respectively. The results show that engagement of ICOS signal increased the expression level of survivin significantly. Survivin can sustain co-stimulatory deficient T cells survival and suppress the apoptosis. Mutant survivin inhibits ICOS signal positive T cells survival and increase its apoptosis. Late-acting co-stimulatory molecules ICOS can suppress the apoptosis and sustain the survival of T cells through the survivin pathway.

Costimulatory blockade with anti-inducible costimulator antibody in combination with CTLA4Ig on prevention of islet allograft rejection / 中华器官移植杂志

Objective To study the effects of costimulatory blockade with anti-inducible costim- ulator antibody(ICOS mAb)in combination with CTLA4Ig on prevention of islet allograft rejection. Methods Experimental animals were randomly divided into 4 groups(10 rats in each group).CT- LA4Ig + ICOS mAb group(group A):intraperitoneal injection of CTLA4Ig on day 0,2,4 and ICOS mAb on day 1,3,5 after islet transplantation;ICOSmAb group(group B):intraperitoneal injection of ICOS mAb on day 1,3,5 after islet transplantation;CTLA4Ig group(group C):intraperitoneal injection of CTLA4Ig on day 0,2,4 after islet transplantation;control group(group D):simple islet transplantation.The islet allograft survival and pathological changes in the transplanted islets after transplantation were observed.By using RT-PCR,the expression of IL-2 and IL-10 mRNA in the transplanted islets was detected.The expression of CD4~+ and CD8~+ T cell was detected by flow cy- tometry.Results In group A,the survival time was obviously prolonged as compared with other three groups and the transplanted islets were near normal under a light microscope.As compared with other three groups,the expression of IL-2 mRNA was significantly decreased in group A(P0.05).The expression of CD4~+ and CD8~+ T cell was not obviously up-regulated on the day 21 after transplantation.Conclusion The blockade of costimulatory signals with ICOS mAb in combination with CTLA4Ig has a favorable effects to restrain the rejection of islet transplantation.