Research progress on the role of costimulatory signaling pathway in xenotransplantation / 器官移植

Organ shortage is a critical factor limiting the development of organ transplantation. Xenotransplantation is expected to resolve the problem of organ shortage, which has become a new research hotspot. Study of costimulatory signaling pathway related to T cell regulation is a hot topic in terms of immunity of xenotransplantation. Since the discovery of costimulatory molecule CD28, multiple costimulatory molecules have been identified, including costimulatory and coinhibitory receptors and their related ligands. Specific T cell activation of donors is the key factor leading to acute immune rejection. The expression and induction of costimulatory molecules on T cells differ during different immune stages, and these costimulatory molecules play a key role in maintaining T cell tolerance and the balance of T cell immune response. At present, increasing attention has been diverted to the role of costimulatory signaling pathway in organ transplantation. In this article, the latest research progress in costimulatory signaling pathway related to xenotransplantation immunity was reviewed, aiming to provide reference for the optimization of xenotransplantation immunosuppression regimen.

Changes and significance of CD8 + CD28 - regulatory T cells in acute phase of Kawasaki disease / 中华微生物学和免疫学杂志

Objective:To investigate the changes of CD8 + CD28 - regulatory T cells (Treg) and its role in the pathogenesis of Kawasaki disease (KD). Methods:A total of 48 children with KD were enrolled in the present study from June 2019 to December 2021. Blood samples were collected from them during acute phage of KD and after intravenous immunoglobulin (IVIG) treatment. Another 32 age-matched healthy children were recruited as control group. The proportions of CD8 + CD28 -Treg cells and the expression of programmed cell death protein 1 (PD-1), factor associated suicide ligand (FasL), inducible T-cell co-stimulator ligand (ICOSL), CD80 and CD86 protein were evaluated by flow cytometry. The expression of Helios, perforin, granzyme B, immunoglobulin-like transcript 3 (ILT3) and ILT4 at the transcription level was measured by real-time PCR. Concentrations of IL-10 and TGF-β in the culture supernatants of CD8 + CD28 -Treg cells stimulated with activated CD4 + T cells were measured by ELISA. Results:⑴ The proportions of CD8 + CD28 -Treg cells and the expression of Helios in patients with acute KD were higher than those in the control group ( P<0.05), and reduced remarkably after IVIG therapy ( P<0.05). The two afore-mentioned indexes were lower in patients combined with coronary artery lesion (CAL) than in those without coronary artery lesion (NCAL) ( P<0.05). ⑵ Compared with the control group, the patients with acute KD showed increased expression of FasL, PD-1, ICOSL and perforin in CD8 + CD28 -Treg cells ( P<0.05). The concentrations of IL-10 and TGF-β1 in the culture supernatants of CD8 + CD28 -Treg cells from patients with acute KD were lower than those in the control group after stimulation with activated CD4 + T cells ( P<0.05), which restored to some extent after IVIG treatment ( P<0.05). All of the six above-mentioned indexes in the CAL group were found to be lower than those in the NCAL group ( P<0.05). There were slight differences in granzyme B expression between different groups ( P>0.05). (3) In comparison with the healthy controls, the patients with acute KD showed overexpressed co-stimulatory molecules such as CD80 and CD86 on CD14 + cells ( P<0.05) and up-regulated expression of inhibitory molecules ILT3 and ILT4 ( P<0.05), which were restored remarkably after IVIG treatment ( P<0.05). Furthermore, the expression of CD80 and CD86 at protein level increased in the CAL group than in the NCAL group ( P<0.05), while the expression of ILT3 and ILT4 at transcriptional level decreased in the CAL group ( P<0.05). Conclusions:Relative insufficiency and impaired function of CD8 + CD28 -Treg cells might be one of the important factors resulting in immune dysfunction and vascular damage in KD patients.

First report of expansion of CD4+/CD28 null T-helper lymphocytes in adult patients with idiopathic autoimmune hemolytic anemia

ABSTRACT CD28 null T helper (Th) cells are rare in healthy individuals, but they are increased in various inflammatory and immune-mediated diseases. In this study, we determined the size of the CD4+/CD28 null T lymphocyte compartment in the peripheral blood of 40 autoimmune hemolytic anemia (AIHA) patients (idiopathic and secondary) and 20 healthy control subjects, using tri-color flow cytometry. The frequency and absolute count of CD4+/CD28 null T helper (Th) cells was significantly higher in idiopathic AIHA patients, compared to healthy controls (p = 0.001 and 0.001, respectively) and to patients with secondary AIHA (p = 0.04 and 0.01, respectively). The percentage of CD4+/CD28 null Th cells was also negatively correlated to the hemoglobin (Hb) level (p = 0.03). These findings demonstrate, for the first time, the expansion of this phenotypically-defined population of T lymphocytes in patients with idiopathic AIHA and indicate that it likely plays an etiological role in the development of this disease. However, establishing the use of this marker for diagnosis or monitoring treatment of such patients needs further studies.

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。

Belatacept: a new weapon in anti-rejection battlefield / 器官移植

As a co-stimulatory blocker against CD28 receptor, belatacept has been approved and applied to the treatment of rejection in organ transplantation in Europe and America. Belatacept has been proven to outperform calcineurin inhibitor (CNI) in improving the long-term survival rate of recipients and grafts, and enhancing graft function. Nevertheless, it might cause a high incidence of rejection. To resolve this issue, transplant workers have attempted to optimize belatacept immunosuppressive regimen and achieved good clinical efficacy. Although belatacept has been proven to exert poor effect on memory T cells, it has potential value in exploring new co-stimulatory molecular targets to optimize immunosuppressive regimes due to its specificity for immune cells and mild adverse effects. In this article, the advent of co-stimulatory blocker, clinical efficacy and application of belatacept, and the causes of belatacept-resistant rejection were reviewed.

Moderate levels of physical fitness maintain telomere length in non-senescent T CD8+ cells of aged men

OBJECTIVES: Immunosenescence is an age-associated change characterized by a decreased immune response. Although physical activity has been described as fundamental for maintaining the quality of life, few studies have evaluated the effects of different levels of exercise on telomere length in aged populations. The present study aimed to analyze the effects of different levels of physical activity, classified by the Maximal oxygen consumption (VO2 max) values, on the telomere length of memory Cluster of differentiation (CD) CD4+(CD45ROneg and CD45RO+), effector CD8+CD28neg, and CD8+CD28+ T cells in aged individuals. METHODS: Fifty-three healthy elderly men (aged 65-85 years) were included in this study. Their fitness level was classified according to the American College of Sports Medicine (ACSM) for VO2 max (mL/kg/min). Blood samples were obtained from all participants to analyze the percentage of CD3, CD4, CD8, CD28+, naïve, and subpopulations of memory T cells by using flow cytometry. Furthermore, using the Flow-FISH methodology, the CD4+CD45RO+, CD4+CD45ROneg, CD8+CD28+, and CD8+CD28negT cell telomere lengths were measured. RESULTS: There was a greater proportion of effector memory T CD4+ cells and longer telomeres in CD8+CD28+ T cells in the moderate physical fitness group than in the other groups. There was a higher proportion of terminally differentiated memory effector T cells in the low physical fitness group. CONCLUSION: A moderate physical activity may positively influence the telomere shortening of CD28+CD8+T cells. However, additional studies are necessary to evaluate the importance of this finding with regard to immune function responses in older men.

Expressions of CD117 and CD28 in patients with newly diagnosed multiple myeloma and their clinical significances / 白血病·淋巴瘤

Objective To investigate the expressions of CD28 and CD117 in patients with newly diagnosed multiple myeloma (MM) and their clinical significances. Methods The clinical data of 115 newly diagnosed MM patients in the First Affiliated Hospital of Zhengzhou University from May 2015 to December 2017 were retrospectively analyzed. The expressions of CD28 and CD117 were detected by using multiparameter flow cytometry. The relationship between the expressions of CD28 and CD117 and MM staging and clinical parameters was analyzed. The staging was performed according to the International Staging System (ISS). Results Among these 115 patients, there were 15 patients with CD117 positive and 30 patients with CD28 positive. Erythrocyte sedimentation rate (r ＝ -0.481, P ＝ 0.039), Cˉreactive protein level (r ＝ -0.314, P＝0.015), the proportion of plasma cells detected by bone marrow cytology (r＝-0.027, P＝0.001) were negatively correlated with CD117 positive expressions. CD28 positive expression was positively correlated with lactate dehydrogenase level (r ＝ 0.249, P ＝ 0.033) and ISS stage (r ＝ 0.319, P ＝ 0.017), while it was negatively correlated with hemoglobin level (r ＝ -0.372, P ＝ 0.026). CD28 positive was associated with light chain type, and nonˉsecretory type mostly occurred (P ＝ 0.016). The incidence of osteolytic lesions in CD28 positive group and CD117 positive group was high, but there was no statistical difference between CD28 positive group, CD117 positive group and CD28 negative group, CD117 negative group (P ＝ 0.052, P＝0.479). Conclusions The positive expression of CD117 in the early stage of MM patients is higher than that in the advanced stage, and the expression of CD28 positive in the advanced stage of MM patients is higher than that in the early stage. CD28 and CD117 can be used as indicators of prognosis stratification in the patients with newly diagnosed MM.

Changes of CD4+CD28null cells and oxidative stress in patients with polycystic ovary syndrome / 中华内分泌外科杂志

Objective To investigate the relationship between CD4+CD28na cells,oxidative stress markers malondialdehyde(MDA) and superoxide dismutase(SOD) and the pathogenesis of polycystic ovary syndrome(PCOS).Methods Thirty-two patients with PCOS(PCOS group) and 28 healthy women(control group) were selected.Six ml of peripheral venous blood were taken from each person,3 ml of which were separated and serum was collected.Sex hormone level,C-reactive protein (CRP),SOD and MDA were detected.Peripheral blood mononuclear cells (PBMCs) were isolated from the other 3 ml blood by centrifugation,and CD4+CD28null T cell subsets were detected by flow cytometry.The characteristics of each detected index of PCOS patients and healthy controls were compared.Results The proportion of CD4+CD28null T cells in the peripheral blood of the PCOS group was significantly higher than that of the control group (P＜0.05).The serum CRP and MDA in PCOS group were both significantly higher than that in the control group,and SOD was significantly lower than the control group(P＜0.05).Correlation analysis showed that the expression of CD4+CD28null T cells in the PCOS group was positively correlated with CRP(P＜0.05) and MDA(P＜0.05) and negatively correlated with SOD (P＜0.05).Conclusions Our study shows a disorder of immunoregulatory mechanism represented by abnormal increase of CD4+CD28null T cell expression and an imbalance of oxidative stress in patients with PCOS.The further study of relationship between these two pathophysiological patterns and PCOS may help to elucidate its pathogenesis.

Research on the expression of CD28 and CD160 in patients with chronic HIV infection / 国际检验医学杂志

Objective To investigate the expression and clinical significance of CD28 and CD160 in patients with chronic HIV infection.Methods 50 patients with HIV from January 2016 to January 2017 were selected as the observation group, and 50 healthy volunteers were recruited as control group.Observe and record general information of all participants, the expression of CD28, CD160 in CD4+and CD8+T cells, initial T cells (TN), the expression of CD160 in central memory T cells (TCM), effector memory T cells (TEM), end effector memory T cells (TEMRA), mean fluorescence intensity (MFI), viral load of two kinds of the cells, analyze the correlation between the expression level of CD28 and CD160 and CD4+T cell count and viral load.Results With the increase of CD160 expression of CD4+T cells, CD4+T cells showed a downward trend, there is a negative correlation between them (r=-0.561, P＜0.05), CD8+T cell number is on the rise, there is a positive correlation between them (r=0.619, P＜0.05), and HIV-RNA copy number increased with the increase of CD160 expression on CD4+T cells and CD8+T cells, both positive (r=0.684, P＜0.05, r=0.459, P＜0.05);with the increase of CD28 cells on the expression of CD4+T, CD4+, CD8+T cells showed a rising trend, there is a positive correlation between them (r=0.621, P＜0.05, r=0.527, P＜0.05, HIV-RNA) and the copy number decreased with the increase of the expression of CD28 and CD4+T on CD8+T cells, there is a negative correlation between them (r=-0.634, P＜0.05, r=-0.582, P＜0.05).There was no significant difference in the positive rate of expression in TEMRA subgroup and MFI of CD160 in CD8+T cell in two groups (P＞0.05).The positive rate and MFI of CD8+T cell CD160 in TN, TCM and TEM subgroups in observation group were significantly higher than those in control group (Tcm), with statistical significance.Conclusion The expression of CD28 in patients with chronic HIV infection is decreased, and the expression of CD160 is increased, which may be related to the decrease of HIV CD4+T and CD8+T cells, in which CD160 mainly affects the memory CD8+T.

Role of CD80, CD86 and their receptors in the immune response in virus infection / 中华实验和临床病毒学杂志

CD80, CD86 and their receptors CD28 and CTLA-4 provide the necessary costimulatory signals for T cell. Virus infection may inhibit the expression of CD80 or CD86 to impair the function of specific T lymphocytes, thus avoid immune surveillance; it can also lead to the disorder of the expression of CD80 or CD86, inducing dysfunction of immune cells in the body, thus causing continuous infection and inflammation. Therefore, costimulation pathway CD80/CD86: CD28/CTLA-4 has great significance for the body to maintain a normal immune response, as well as the clearance of the virus and the recovery of the body. This article summarizes the studies on CD80, CD86 and their receptors in viral infection in recent years, and provides theoretical ideas and references for the control of viral infection.

Research progress of new mumber HHLA2 of B7 family / 中国免疫学杂志

HHLA2 is a newly discovered B7 family member.HHLA2 appears to have limited expression in normal tissues.TMIGD,one of the receptors HHLA2 is established.Similar to HHLA2,TMIGD2 is absent in mouse and rat while it is found in human and higher primates.HHLA2 with inhibition of CD4 and CD8 T cell proliferation,but also can inhibit the role of T cells secrete some cytokines.HHLA2 protein is absent in most normal tissues,but mainly expressed on epithelial cells of a few tissues.But HHLA2 is widely expressed in various human cancers such as lung cancer,breast cancer and osteosarcoma et al,that make HHLA2 might be a new target for human cancers immunotherapy.

Clinical significance of abnormally expressed PD-1 on CD4+CD28-and CD4+CD28+T cells in periph-eral blood of SLE patients / 中华微生物学和免疫学杂志

Objective To investigate the clinical significance of abnormally expressed PD-1 on CD 4+CD 2 8+/-T cells in peripheral blood of patients with systemic lupus erythematosus ( SLE ) . Methods Peripheral blood samples were collected form 50 patients with primary SLE and 40 healthy subjects and used to isolated mononuclear cells. Expression of CD4+CD28-, CD4+CD28+, CD4+CD28+PD-1+and CD4+CD28-PD-1+T cells in peripheral blood samples of the two groups were detected by flow cytometry. Clinical data of SLE patients were collected. Based on SLE disease activity index (SLEDAI), SLE patients were classified into two groups: stable group (SLEDAI<10) and active group (SLEDAI≥10). Based on the condition of renal damage, they were also divided into two groups: lupus nephritis group and non-lupus ne-phritis group. Differences in T cell expression were compared among these groups. Statistical analysis was performed to analyze the relationships of different T cell subsets with laboratory and clinical parameters rela-ting to SLE and SLEDAI. Results The percentages of peripheral CD4+CD28-, CD4+CD28+PD-1+and CD4+CD28-PD-1+T cells of active group were higher than those of stable and healthy control groups ( P<0. 05). Moreover, patients with lupus nephritis had higher percentages of these T cell subsets than those without (P<0. 01). SLE patients who were positive for anti-dsDNA or anti-SmRNP antibody, or had de-creased complement C3, thrombocytopenia or decreased lymphocytes had higher percentages peripheral CD4+CD28-T cells than those in the corresponding negative group. SLE patients who were positive for anti-dsDNA or anti-SmRNP antibody, or had decreased complement C3, complement C4 or lymphocytes showed en-hanced expression of peripheral CD4+CD28+PD-1+T cells as compared with those in the corresponding nega-tive group. SLE patients positive for anti-dsDNA antibody, or with decreased complement C3 or lymphocytes or suffering from alopecia had higher percentages of peripheral CD4+CD28-PD-1+T cell than those in the cor-responding negative group. Differences between different groups were statistically significant (P<0. 05). Conclusion Abnormal expression of CD4+CD28-T cells and PD-1 on CD4+CD28-and CD4+CD28+T cells in peripheral blood of patients with SLE has certain correlation with laboratory parameters and clinical indicators.

Day-time Variation of Serum CD28 in Asthmatic Adults Treated with ICS and Adults Without Asthma / 医学研究杂志

Objective To observe the day-time variation of serum CD28 in asthmatic adults treated with ICS and adults without asthma. Methods Serum CD28 level were measured at 3-hour intervals from 8: 00 to 17: 00 h in 82 adult participants with asthma and in 40 healthy participants without asthma during Jan 2015 to Jan 2017. CD28 levels at each timepoints of asthma patients before and after ICS therapy and healthy participants were compared by repeated measures analysis of variance. Results The level of CD28 of asthma patients before ICS were significantly higher than heathy control (F1, 120 = 232. 1, P = 0. 000). The CD28 lever of asthma patients before ICS was highest at 8: 00h and continuously reduced during the day. After ICS therapy, the level of CD28 were significantly decreased, and were significantly higher than healthy control group at 8: 00h (t = 4. 59, P ＜ 0. 01) and 11: 00h (t = 3. 51, P ＜ 0. 01). Conclusion The level of serum CD28 changed significantly and rhythmically in asthma patients, which may be a potential marker or therapeutic target in the diagnosis or therapy of asthma.

Activation of CD8+T cells regulated by γ-aminobutyric acid and its receptors / 器官移植

Objective To evaluate the effect of γ-aminobutyric acid (GABA) and its receptors upon the proliferation of CD8+T cells.Methods The splenic CD8+T cells of Balb/c mice were obtained by CD8+f cell magnetic bead sorting kit.Under the effect of CD3/CD28-activated magnetic bead,CD8+T cells were stimulated by different concentrations of GABA.5-bromo-2-deoxyuridine (BrdU) labeling and flow cytometry were performed to detect the proliferation of CD8+T cells.The expression levels of GABA-A and GABA-B receptor before and after CD8+T cell activation were compared by fluorescent quantitative real-time polymerase chain reaction (PCR).Result Flow cytometry result revealed that GABA could inhibit the proliferation of activated CD8+T cells,manifested as significant decrease in the quantity of CD152+CD8+T cells.Fluorescent quantitative real-time PCR demonstrated that GABA-A receptor subtypes α2,α6 and GABA-B receptor subtype 1a were expressed only when the CD8+T cells were activated.After CD8+T cell activation,the quantity of GABA-A receptor subtypes α3,αs,β2,β3,γ1,γ2 and θ were significantly increased,whereas the quantity of GABA-B2R and GABA-B1b did not significantly differ before and after CD8+T cell activation.Conclusions GABA can suppress the proliferation of activated CD8+T cells.The activation of CD8+T cells is regulated by GABA receptors.However,the underlying mechanism remains to be elucidated.

The effects of paclitaxel on the levels of CD28,CTLA-4 and BAFF in experimental autoimmune encephalomyelitis / 中国比较医学杂志

Objective To discuss the effects of Paclitaxel(PTX) on levels of CD28 and CTLA-4,B lymphocyte stimulator(BAFF) in experimental autoimmune encephalomyelitis(EAE).Methods The 50 rats were divided into 5 groups by the random number table, 10 rats in each group,the doses of small group,Middle group, High group were 1 mg/kg,2 mg/kg,4 mg/kg by intraperitoneal injection for 10 consecutive days, the normal group and model group were injected 0.9% NS 2 mL,Using brain tissue score to estimate the neurological dysfunctions of rats.Using flow cytometry to detect the levels of CD28 and CTLA-4,using enzyme-linked immunosorbent (ELISA) to detect the levels of BAFF.Results The brain tissue score in PTX experimental groups were lower than model group,the comparative differences between groups were statistically significant(P < 0.01);The levels of CD28 in PTX groups were lower than EAE group,the comparative differences between groups were statistically significant(P < 0.01).The levels of CTLA-4 in PTX groups were higher than EAE group,the comparative differences between groups were statistically significant(P < 0.01);the content of BAFF in all PTX groups were lower than EAE control group.Conclusions PTX could decrease the brain tissue score,the mechanism may adjust the express of CD28、CTLA-4 in brain and the expression of BAFF.PTX may have preventive and therapeutic effects on EAE rats.

Influence of Treg cells and HBV genotype on sustained response and drug resistance in the treatment with nucleoside drugs

We aimed to investigate the influence of regulatory T cells including CD4+CD25+, CD8+CD28- and hepatitis B virus (HBV) genotype on sustained virological response and tolerance of nucleoside drugs. One hundred and thirty-seven patients were enrolled. Lamivudine was administered to 84 patients. Entecavir was administered to the other 53 patients. Before treatment, biochemical tests, HBV DNA load, HBV serum level, HBV genotype, PB CD3+, CD4+, CD8+, CD4+CD25+/CD3+, and CD8+CD28-/CD3+ frequencies were measured. Based on HBV DNA loads after 4 weeks of therapy, patients were divided into response group and suboptimal response group. The lamivudine group received treatment continuously, and then patients were categorized into non-resistance group and resistance group. Compared with the suboptimal response and resistance groups for lamivudine, CD4+CD25+/CD3+ levels were higher in the response and non-resistance groups (t=4.372, P=0.046; t=7.262, P=0.017). In the non-resistance group, CD8+CD28-/CD3+ frequency was lower than in the resistance group (t=5.527, P=0.037). Virus load and hepatitis B E antigen (HBeAg)-positive rate were significantly lower than in the response and resistance group (t=2.164, P=0.038; X2=4.239, P=0.040; t=2.015, P=0.044; X2=16.2, P=0.000). Incidence of drug resistance was high in patients with virogene type C. For the virological response to entecavir, CD8+CD28-/CD3+ level was significantly lower than that of the suboptimal response group (t=6.283, P=0.036). Response and suboptimal response groups were compared in CD3+, CD4+, CD8+, CD4+CD25+/CD3+ and virus genotype, and differences were not statistically significant (P>0.05). Baseline regulatory T cells including CD4+CD25+/CD3+ and CD8+CD28-/CD3+ frequencies have a relationship with the incidence of rapid virological response and the resistance to nucleoside drugs. Patients with HBV genotype C receiving lamivudine more often underwent drug resistance. Antiviral efficacy and the resistance to lamivudine were closely correlated with baseline factors; the same cannot be found for entecavir.

The immunoregulatory effect of CD8+CD28-T lymphocytes in an experimental bone marrow mesenchymal stem cell treatment of autoimmune encephalomyelitis / 中华物理医学与康复杂志

Objective To study the immune system regulatory effects of CD8+CD28-regulatory T lymphocytes in an experimental bone marrow mesenchymal stem cell treatment of autoimmune encephalomyelitis.Methods A model of autoimmune encephalomyelitis (EAE) was established in twenty-eight C57BL/6 female mice,6 to 8 weeks old weighing 16 to 20 g using myelinoligodendrocyte glycoprotein 35-55 amino acid peptide (MOG35-55).The mice were randomly divided into a phosphate-buffered solution (PBS) group (n =7),an MSCs-Low group [n =7 which received an injection of 2× 105 mesenchymal stem cells (MSCs)],an MSCs-Med group (n=7,1× 106 MSCs),and an MSCs-High group (n=7,5×106 MSCs).Their clinical condition was then evaluated daily.On the 15th day after the MOG35-55 immunization,the different MSC doses were administered intravenously via the tail.On the 30th day the mice were sacrificed to observe any neuropathology of the spinal cord.At the same time,FACS flow cytometry was used to assay CD8+CD28-T cells in the spleen.Results Compared with the PBS control group,the MSC treatment effectively alleviated illness among the mice by the 15th day after the immunization.The maximum and average disease scores and clinical illness scores had all improved significantly.The medium dosage worked best.Neuropathological analysis showed that the MSC treatment could significantly reduce the invasion of inflammatory cells and minimize demyelination in the spinal cord.Furthermore,the CD8+ CD28-regulatory T cells in the spleens of the MSCtreated animals increased compared with the PBS control group,though the secreted levels of IL-10 showed no obvious difference.Conclusions Treatment with MCSs can promote the recovery of neural function in autoimmune encephalomyelitis,at least in mice.CD8+CD28-regulatory T cells may not be the main effector cells,playing only a synergistic therapeutic role.

Unusual CD4⁺CD28⁻ T Cells and Their Pathogenic Role in Chronic Inflammatory Disorders

CD28 is a primary co-stimulatory receptor that is essential for successful T cell activation, proliferation, and survival. While ubiquitously expressed on naive T cells, the level of CD28 expression on memory T cells is largely dependent on the T-cell differentiation stage in humans. Expansion of circulating T cells lacking CD28 was originally considered a hallmark of age-associated immunological changes in humans, with a progressive loss of CD28 following replicative senescence with advancing age. However, an increasing body of evidence has revealed that there is a significant age-inappropriate expansion of CD4⁺CD28⁻ T cells in patients with a variety of chronic inflammatory diseases, suggesting that these cells play a role in their pathogenesis. In fact, expanded CD4⁺CD28⁻ T cells can produce large amounts of proinflammatory cytokines such as IFN-γ and TNF-α and also have cytotoxic potential, which may cause tissue damage and development of pathogenesis in many inflammatory disorders. Here we review the characteristics of CD4⁺CD28⁻ T cells as well as the recent advances highlighting the contribution of these cells to several disease conditions.

Effect of leflunomide on peripheral blood CD28/CTLA-4 costimulatory molecules expression in guinea pig with EAE / 中国生化药物杂志

Objective To investigate immunological mechanism underlying leflunomide ( LEF ) against experimental allergic encephalomyelitis ( EAE) by studying the effects of LEF on peripheral blood CD28/CTLA-4 costimulatory molecules expression in guinea pig with EAE.Methods 50 adult female guinea pigs were randomly divided into normal control group,low dose group,EAE control group,middle dose group,and high dose group, 10 guinea pigs in each group respectively.Low, medium and high dose group were treated with LEF 10 mg/kg· D, 20 mg/kg· D and 40 mg/kg· D orally, 1 times/day, to the termination of the experiment.The expression of CD28, CTLA-4 were detected by flow cytometry, incidence was recorded at the same time.Results Compared with EAE control group,high dose and middle dose group incubation period were prolonged, progress period were shorten and neurological dysfunction score decreased(P<0.05).Compared with normal control group, the expression of CD28 of EAE control group increased and the decreased expression of CTLA-4 (P<0.05).High, middle dose treatment group compared with EAE control group CD28 down regulated expression (P<0.05), but the expression of CTLA-4 increased(P<0.05).Among the treatment groups, of CD28 molecules with high dose group decreased significantly(P<0.05), the expression of CTLA-4 molecules with high dose treatment groups upregulated significantly (P<0.05).Correlation analysis showed that the EAE control group, the treatment group the CD28/CTLA-4 ratio in peripheral blood and nerve dysfunction score is proportional ( r=0.85, P=0.002; r=0.77, P=0.000).Conclusion LEF can reduce EAE guinea pig neurological symptoms, the better and the higher dose effect.Its mechanism may be through down-regulation of CD28 molecules in peripheral blood, upregulation of the expression of CTLA-4 molecule.so as to reduce the inflammatory response, relieve the clinical symptoms.

Correlation research between CTLA-4Ig impacting on Th17 and Treg cells expressed in spleen of lupus mice and its intervention role in lupus-like symptoms of B6.MRL-Faslpr/J lupus mice / 中国免疫学杂志

Objective:To observe the correlation between the B7 blocker,CD28 and cytotoxic T lymphocyte-associated antigen 4 immunoglobulin (CTLA-4Ig) impacting on Th17 and Treg cells expressed in the spleen of lupus mice and its intervention role in lupus-like symptoms of B6.MRL-Faslpr/J lupus mice.Methods:Sixteen 4-month-old female B6.MRL-Faslpr/J mice were selected and randomly divided into treatment group ( groupⅠ) and control group ( groupⅡ);injected the same amount of CTLA-4Ig and PBS intra-venously,checked their 24 hour urine protein ,ANA antibody,ds-DNA antibodies before and after the intervention.Two weeks after the intervention ,detected serum IL-17A,and the percentage of Th17 and Treg cells in their spleen.Results:Two weeks after the last inter-vention,24-hour urine protein,serum ANA and ds-DNA in groupⅠdecreased,and all the differences were statistically significant (P<0.05) compared with groupⅡ.Two weeks after the last intervention,serum IL-17A and the proportion of Th17 cells in the spleen in groupⅠwere lower than those in groupⅡ, but Treg cells in CD4+T lymphocytes was higher than that in groupⅡ,all the differences were statistically significant ( P<0.05).Conclusion:CTLA4-Ig can relieve the lupus-like symptoms in lupus mice;raising the number of Treg cells and decreasing the number of Th17 cells may be one of the important mechanisms for CTLA-4Ig to alleviate lupus-like symptoms in B6.MRL-Faslpr/J mice.