Heat-Inactivation of Human Serum Destroys C1 Inhibitor, Pro-motes Immune Complex Formation, and Improves Human T Cell Function.

Heat-inactivation of sera is used to reduce possible disturbing effects of complement factors in cell-culture experiments, but it is controversially discussed whether this procedure is appropriate or could be neglected. Here, we report a strong impact of heat-inactivation of human sera on the activation and effector functions of human CD4+ T cells. While T cells cultured with native sera were characterized by a higher proliferation rate and higher expression of CD28, heat-inactivated sera shaped T cells towards on-blast formation, higher cytokine secretion (interferon γ, tumor necrosis factor, and interleukin-17), stronger CD69 and PD-1 expression, and increased metabolic activity. Heat-inactivated sera contained reduced amounts of complement factors and regulators like C1 inhibitor, but increased concentrations of circulating immune complexes. Substitution of C1 inhibitor reduced the beneficial effect of heat-inactivation in terms of cytokine release, whereas surface-molecule expression was affected by the addition of complex forming anti-C1q antibody. Our data clearly demonstrate a beneficial effect of heat-inactivation of human sera for T cell experiments but indicate that beside complement regulators and immune complexes other components might be relevant. Beyond that, this study further underpins the strong impact of the complement system on T cell function.

CD28 deficiency attenuates primary blast-induced renal injury in mice via the PI3K/Akt signalling pathway.

INTRODUCTION: Primary blast affects the kidneys due to direct shock wave damage and the production of proinflammatory cytokines without effective treatment. CD28 has been reported to be involved in regulating T cell activation and secretion of inflammatory cytokines. The aim of this study was to investigate the influence of primary blast on the kidney and the effect of CD28 in mice. METHODS: A mouse model of primary blast-induced kidney injury was established using a custom-made explosive device. The severity of kidney injury was investigated by H&E staining. ELISA was applied to study serum inflammation factors' expression. Western blot assays were used to analyse the primary blast-induced inflammatory factors' expression in the kidney. Immunofluorescence analysis was used to examine the PI3K/Akt signalling pathway. RESULTS: Histological examination demonstrated that compared with the primary blast group, CD28 deficiency caused a significant decrease in the severity of the primary blast-induced renal injury. Moreover, ELISA and western blotting revealed that CD28 deficiency significantly reduced the levels of interleukin (IL)-1ß, IL-4 and IL-6, and increased the IL-10 level (p<0.05). Finally, immunofluorescence analysis indicated that PI3K/Akt expression also changed. CONCLUSIONS: CD28 deficiency had protective effects on primary blast-induced kidney injury via the PI3K/Akt signalling pathway. These findings improve the knowledge on primary blast injury and provide theoretical basis for primary blast injury treatment.

Evaluation of a TGN1412 analogue using in vitro assays and two immune humanized mouse models.

Cytokine release syndrome (CRS) is a serious and potentially life-threatening complication typically associated with biological drug products. Pre-clinical testing in vitro and in vivo studies using non-human primates had failed to reliably predict CRS. To determine if bone marrow-thymus-liver (BLT) humanized mice with a fully engrafted human immune system or a CD34-humanized mouse model could predict CRS, we tested an anti-CD28 monoclonal antibody (mAb) similar to TGN1412. This TGN1412 analogue (TGN1412A) was initially tested in vitro and found to produce significant dose-dependent increases in cytokine production. For in vivo studies, adalimumab, an anti-tumor necrosis factor-alpha antibody known not to cause CRS, served as a negative control. We evaluated immune cell activation and cytokine expression in three independent experiments. In BLT humanized mice, significant increases in levels of human cytokines were identified in animals treated with anti-CD28 mAb. As expected, CD28+ cell detection was strongly reduced in the anti-CD28 treated group. Increased T cell activation was also observed. The control group did not show reductions in CD28+ T-cells and did not experience increased cytokine levels. Responses by CD34-humanized mice showed no significant differences between adalimumab and anti-CD28 treatment at doses used to test BLT-humanized mice. These results suggest that the TGN1412A produces similar results in vitro to the original TGN1412 monoclonal antibody. The BLT immune humanized mice but not the CD34 humanized mice produce both robust and specific cytokine responses and may represent a pre-clinical model to identify CRS.

T-cell differentiation and CD56+ levels in polypoidal choroidal vasculopathy and neovascular age-related macular degeneration.

Polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (AMD) are prevalent age-related diseases characterized by exudative changes in the macula. Although they share anatomical and clinical similarities, they are also distinctly characterized by their own features, e.g. vascular abnormalities in PCV and drusen-mediated progression in neovascular AMD. PCV remains etiologically uncharacterized, and ongoing discussion is whether PCV and neovascular AMD share the same etiology or constitute two substantially different diseases. In this study, we investigated T-cell differentiation and aging profile in human patients with PCV, patients with neovascular AMD, and age-matched healthy control individuals. Fresh venous blood was prepared for flow cytometry to investigate CD4+ and CD8+ T-cell differentiation (naïve, central memory, effector memory, effector memory CD45ra+), loss of differentiation markers CD27 and CD28, and expression of aging marker CD56. Patients with PCV were similar to the healthy controls in all aspects. In patients with neovascular AMD we found significantly accelerated T-cell differentiation (more CD28-CD27- cells) and aging (more CD56+ cells) in the CD8+ T-cell compartment. These findings suggest that PCV and neovascular AMD are etiologically different in terms of T cell immunity, and that neovascular AMD is associated with T-cell immunosenescence.

CD8+CD28+/CD8+CD28- T cell equilibrium can predict the active stage for patients with inflammatory bowel disease.

BACKGROUND/AIM: The balance of blood CD8+CD28+/CD8+CD28- T cells has been verified to be vital for patients with ulcerative colitis (UC), but their role in inflammatory bowel disease (IBD) remains unknown. This investigation aimed to evaluate the efficiency of the balance in predicting the active stage in IBD patients. METHODS: Fifty-three IBD subjects, including 31 UC and 22 Crohn's disease (CD) patients, were enrolled, and their peripheral blood CD8+CD28+ and CD8+CD28- T cell levels were tested using flow cytometry. The risk factors related to prognosis were compared between UC and CD patients. A 1-year follow-up was performed for all the IBD patients, and the CD8+ T cells and their ratio were compared at the 3rd, 6th, 9th, and 12th months during follow-up. The sensitivity and specificity of the CD8+ T cell level and balance were analyzed through receiver operator characteristic (ROC) curves. The cumulative remission lasting rates (CRLRs) under the different factors were analyzed using the Kaplan-Meier method. RESULTS: Higher prescription rates of immunosuppressants, steroids, probiotics, and biological agents (BAs) were found in CD subjects in comparison to UC subjects (P=0.005, 0.024, 0.034, and 0.001), as was a higher active rate during follow-up (95.5% of CD patients vs 67.7% of UC patients, P=0.035). The CD8+CD28+ T cell level and the CD8+CD28+/CD8+CD28- T cell ratio were significantly higher in UC patients than in CD patients, but the reverse was true for CD8+CD28- T cells during follow-up at the 9th and 12th month (all P<0.05). The diagnostic models of the initial CD8+CD28+ and CD8+CD28- T cell numbers and the CD8+CD28+/CD8+CD28- T cell ratio in predicting the active stage were found to be significant, with areas under the curves (AUCs) of 0.883, 0.098, and 0.913 for UC subjects (with 95% CI: 0.709-0.940, 0.009-0.188, and 0.842-1.003; P=0.001, 0.00, and 0.000) and 0.812, 0.078, and 0.898 for CD subjects (with 95% CI: 0.683-0.957, 0.003-0.158, and 0.837-0.998; P=0.003, 0.00, and 0.000). The cut-off values showed that when the ratios were 1.30 for UC and 1.22 for CD patients, the best sensitivity and specificity were observed, with 91.6% and 89.0% for UC and 88.5% and 85.1% for CD, respectively. The CRLRs were significantly higher in female, non-BA-treated, non-surgical IBD subjects when compared to male, BA-treated, surgical subjects (P=0.031, 0.000, and 0.000). The number of CD8+CD28+ and CD8+CD28- T cells and the CD8+CD28+/CD8+CD28- T cell ratio were correlated with BA treatment and surgery (all P<0.05). CONCLUSION: The CD8+CD28+/CD8+CD28- T cell balance, expected to be a novel immunologic marker, presented a satisfactory efficiency with high sensitivity and specificity in predicting the active stage in UC and CD patients, and the balance was closely related to the use of BAs and surgery.

Association of CTLA4 and CD28 Gene Variants and Circulating Levels of Their Proteins in Patients with Breast Cancer.

BACKGROUND/AIM: Breast cancer is one of the most common and lethal types of cancer among women. We focused on the importance of the immune system in the etiology of breast cancer by investigating critical polymorphisms of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and cluster of differentiation 28 (CD28) gene, and circulating levels of these proteins. MATERIALS AND METHODS: A total of 79 patients with breast cancer and 76 healthy controls were enrolled. Molecular assessment of CTLA4 (rs231775&rs5742909) and CD28 (rs3116496) variants were determined with polymerase chain reaction restriction fragment length polymorphism techniques. Circulating levels of soluble forms of CTLA4 and CD28 were analyzed by ELISA. RESULTS: Although no significant association was found between study groups, CTLA4 +49AA genotypic frequency, and sCTLA4 and sCD28 levels were higher in patients. Some clinicopathological features were also related with CTLA4 and CD28 variants and blood levels. CONCLUSION: While CTLA4 +49AA genotype is increased in patients with breast cancer, the CTLA4 -318T allele may have a prognostic value. In addition, sCTLA4 and sCD28 can be used for diagnostic purposes in patients with breast cancer.

Higher preoperative serum levels of PD-L1 and B7-H4 are associated with invasive and metastatic potential and predictable for poor response to VEGF-targeted therapy and unfavorable prognosis of renal cell carcinoma.

Renal cell carcinoma (RCC) is an immunogenic and proangiogenic cancer. Although antivascular endothelial growth factor (VEGF) therapies achieve impressive responses in some patients, many tumors eventually develop resistance to such therapy. The B7 family molecules such as CTLA-4, PD-1, and PD-L1 are pivotal players in immune checkpoints that positively or negatively regulate various immune responses. Recently, immunotherapy based on blocking immune checkpoints with anti-CTLA4, anti-PD-1, or anti-PD-L1 antibodies has been proposed as a potential new approach to the treatment of metastatic RCC. Higher expression of PD-L1 and B7-H4 in the tumors is associated with a poor prognosis in RCCs, however, the clinical impact of serum levels of B7 family molecules has not been elucidated in patients with metastatic RCCs receiving VEGF-targeted agents. We assessed the preoperative serum levels of B7 family molecules, including CD80, CD86, PD-1, PD-L1, B7-H3, B7-H4, and CTLA-4, and CD28 in RCC patients, and determined their relations with various clinicopathological characteristics. Elevated preoperative serum levels of PD-L1 and B7-H4 were correlated with less differentiated tumors, higher invasive and metastatic potential, a worse response to anti-VEGF therapy, and shorter overall survival. These findings suggested that investigating preoperative serum levels of PD-L1 and B7-H4 might not only be useful to assess the biological aggressiveness of RCCs, but also to predict the efficacy of anti-VEGF therapy and the eventual prognosis, indicating the future design of clinical trials of therapies targeting immune checkpoint in advanced RCCs.

Expression of CD27, CD28 and IL-17A in peripheral blood from patients with colorectal carcinoma.

OBJECTIVE: To compare the different expressions of CD27, CD28, IL-17A, IFN-γ and TNF-α in the peripheral blood sampled from patients with colorectal carcinoma and healthy volunteers. PATIENTS AND METHODS: Vδ2 T cells were isolated from the peripheral blood mononuclear cells (PBMCs) of patients with the colorectal carcinoma (CRC, n = 30) and healthy controls (HC, n = 21). The proportion of CD27, CD28, IL-17A, IFN-γ and TNF-α of Vδ2 T cells was detected by the flow cytometry. RESULTS: We found that the proportion of IL-17A of Vδ2 T cells in PBMCs was higher in the CRC vs. the HC group (p < 0.05). A significant positive correlation was observed between the expression of IFN-γ and TNF-α of Vδ2 T cells. In the CRC patients, the proportions of IL-17A of CD27- Vδ2 T cells and CD28+ Vδ2 T cells were higher than those of CD27+ Vδ2 T cells and CD28- Vδ2 T cells, whereas the expression of IFN-γ and TNF-α of CD27-Vδ2 T cells was lower than that of CD27+ Vδ2 T cells. CONCLUSIONS: Vδ2 T cells from PBMCs had higher expression of IL-17A in CRC patients than that in the HC group. The expression of IFN-γ and TNF-α of Vδ2 T cells from PBMCs was positively correlated. The cytokine profiles of peripheral Vδ2 T cells were likely determined by a CD27 and CD28 involving mechanism.

Advanced Lung Cancer Is Associated with Decreased Expression of Perforin, CD95, CD38 by Circulating CD3+CD8+ T Lymphocytes.

It is known that dysregulation of the immune system is closely related to the development of lung cancer and that CD8+T lymphocytes play a critical role in antitumor immunity. We analyzed the percentage of CD3+CD8+ T cells in peripheral blood, and expressions of the activated molecules, perforin, CD95, CD28, HLA-DR and CD38 in circulating CD3+CD8+ T cells from 68 lung cancer cases with stage I∼II and 61 lung cancer cases with stage III∼IV by flow cytometry. 61 lung cancer cases with stage III∼IV were followed up for more than 6 months and survival time was recorded. The percentages of perforin+ cells, CD95+ cells and CD38+ cells in fresh CD3+CD8+ T lymphocytes of stage III∼IV group were lower than those of stage I∼II group (p=0.021; p=0.043; p=0.036). And an increased percentage of CD3+CD8+perforin+ cells was shown to have a positive effect on the survival time in stage III∼IV lung cancer patients (p=0.043). Advanced lung cancer patients have characteristics of impairment in the cytotoxicity of circulating CD3+CD8+ T lymphocytes and perforin expression in circulating CD3+CD8+ T cells might be used as a prognostic biomarker for the advanced lung cancer.

Lymphocyte senescence in COPD is associated with decreased histone deacetylase 2 expression by pro-inflammatory lymphocytes.

BACKGROUND: Histone acetyltransferases (HAT) and histone deacetylases (HDAC) are enzymes that upregulate and down-regulate pro-inflammatory gene transcription respectively. HDAC2 is required by corticosteroids to switch off activated inflammatory genes and is reduced in lung macrophages in COPD. We have shown that COPD patients have increased steroid resistant CD28null (senescent) pro-inflammatory T and NKT-like peripheral blood cells (particularly CD8+ subsets) and we hypothesized that these changes would be associated with a loss of HDAC2 from these senescent pro-inflammatory lymphocytes. METHODS: Blood was collected from 10 COPD and 10 aged-matched controls. Intracellular pro-inflammatory cytokines, IFNγ and TNFα, and expression of CD28, HDAC2 and HAT, were determined in lymphocyte subsets in the presence of ± 5 mg/ml theophylline (HDAC2 activator), 10 µM prednisolone and 2.5 ng/ml cyclosporine A (immunosuppressant), using flow cytometry. RESULTS: There was a loss of HDAC2 from CD28null CD8+ T and NKT-like cells in COPD. There was a significant negative correlation between HDAC2 expression and the percentage of CD28null CD8+ T and NKT-like cells producing IFNγ or TNFα in all subjects (eg, COPD: R = -.763, p < 0.001 for T-cell IFNγ). There was a synergistic upregulation of HDAC2 and associated decrease in pro-inflammatory cytokine production in CD28nullCD8+ T and NKT-like cells in the presence of 5 mg/L theophylline + 10(-6) M prednisolone or 2.5 ng/mL cyclosporine A (CsA). CONCLUSIONS: Lymphocyte senescence in COPD is associated with loss of HDAC2 in CD28nullCD8+ T and NKT-like cells. Alternative treatment options such as combined theophylline with low-dose CsA, that inhibit these pro-inflammatory cells, may reduce systemic inflammation in COPD.

Individual and Combined Effects of CTLA4-CD28 Variants and Oxidant-Antioxidant Status on the Development of Colorectal Cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most frequent cancer worldwide. Research has revealed the contributions of the immune system and anti-inflammatory pathways in the development of cancer. The balance between cluster of differentiation 28 (CD28) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) signaling is important for the regulation of immune responses. The oxidant-antioxidant balance by sustaining redox control via several defense mechanisms is also an important factor for the progression of cancer. The aim of the present study was to determine the distribution of CTLA4/CD28 variants and oxidant-antioxidant status in patients with CRC. MATERIALS AND METHODS: This study enrolled 80 patients with CRC and 115 healthy controls. We used a spectrophotometric assay to detect the levels of lipid peroxidation products malon dialdehyde (MDA) and lipid hydroperoxide (LHP), and measured the concentration of protein damage products, advanced oxidation protein products (AOPP) and protein carbonyl (PCO). Additionally, antioxidant levels were detected by measuring copper, zinc, superoxide dismutase (Zn-Cu SOD) and total thiol (T-SH) levels, and advanced glycation end-products (AGEs). The CTLA4 -318C>T, CTLA4 49A>G and CD28C>T genotypes were determined by using restriction enzymes. RESULTS: AOPP and PCO levels were increased in patients with CRC as well as those of LHP, MDA and AGE, while the levels of antioxidants such as Cu-Zn SOD and T-SH were lower. Lower serum levels of CTLA4 and higher serum levels of CD28 were detected in patients and, an association of the CTLA4 -318C/T polymorphism was found in patients with CRC. CONCLUSION: Our oxidative stress was increased in patients with CRC, suggesting the contribution of this disturbed oxidative status to serum CTLA4 and CD28 levels, and to the pathogenesis of CRC.

Perforin, CD28 and CD95 expression in circulating CD4 and CD8 cells as predictors of head and neck (H&N) cancer patient survival.

Long-term survival of H&N cancer patients has not improved significantly over the last 30 years. The possibility of using circulating blood cell phenotypes as a prognostic biomarker of H&N cancer patient was investigated in this study. Pre-treatment, circulating T lymphocyte subpopulations as well as the survival time of the patients in question were studied. Upregulated CD4+ perforin+ and CD8+ CD95+ but downregulated CD4+ CD28+ (p < 0.001) were detected in H&N cancer patients. With 3 years of follow-up time, an increase in the frequency of the pre-treatment, circulating CD4+ perforin+ cells and CD8+ perforin+ cells was showed to have reverse effects on the survival time in H&N cancer patients (p < 0.01). Detection of perforin+ frequency in CD4+ and CD8+ lymphocyte by FACS is fast, simple and cost-effective. A potential role of perforin expression in CD4+ and CD8+ cells as a prognostic biomarker for H&N cancer patient in the clinical setting was suggested.

Defective CD8+CD28+ regulatory T cell suppressor function in rheumatoid arthritis is restored by tumour necrosis factor inhibitor therapy.

Balanced immunoregulatory networks are essential for maintenance of systemic tolerance. Disturbances in the homeostatic equilibrium between inflammatory mediators, immune regulators and immune effector cells are implicated directly in the pathogenesis of autoimmune diseases, including rheumatoid arthritis (RA). In this study we characterize the peripheral blood CD8(+) CD28(-) regulatory T cells (Treg) contribution to the immunoregulatory network in health and in RA. In health, CD8(+) CD28(-) Treg are suppressive but, unlike CD4(+) Treg , they function predominantly through the action of soluble mediators such as interleukin (IL)-10 and transforming growth factor (TGF)-ß. Neutralization of TGF-ß consistently reduced CD8(+) CD28(-) Treg suppressor function in vitro. RA, CD8(+) CD28(-) Treg are increased numerically, but have reduced expression of inducible co-stimulator (ICOS) and programmed death 1 (PD-1) compared to healthy or disease controls. They produce more IL-10 but autologous T cells express less IL-10R. This expression was found to be restored following in-vitro addition of a tumour necrosis factor inhibitor (TNFi). Deficiencies in both the CD8(+) CD28(-) Treg population and reduced sensitivity of the T responder cells impact upon their regulatory function in RA. TNFi therapy partially restores CD8(+) CD28(-) Treg ability in vivo and in vitro, despite the defects in expression of functionally relevant molecules by RA CD8(+) CD28(-) Treg compared to healthy controls. This study places CD8(+) CD28(-) Treg cells in the scheme of immune regulation alongside CD4(+) Treg cells, and highlights the importance of understanding impaired responsiveness to regulation that is common to these suppressor subsets and their restored function in response to TNFi therapy.

Serum antibodies against CD28-- a new potential marker of dismal prognosis in melanoma patients.

BACKGROUND: Autoantibodies against CD28 have been found in patients with autoimmune and atopic diseases. These antibodies may act as superagonists and activate T cells but may also be antagonistic or induce immunosuppressive effects by activating regulatory T cells. Autoimmunity in melanoma patients has been discussed controversially. OBJECTIVE: We investigated 230 melanoma patients for the occurrence of CD28 antibodies and the effect of the latter on overall and progress-free survival. METHODS: We constructed an ELISA assay to measure CD28 serum antibodies. 230 patients with melanoma and a control-group of 625 patients consistent of 212 patients with virus hepatitis b or c, 149 patients with allergies, 78 patients with psoriasis, 46 patients with plasmocytoma and 140 healthy blood donors were investigated for the occurrence of CD28 antibodies. RESULTS: CD28 abs occur at a higher percentage in patients with melanoma and in patients with viral hepatitis than in other groups investigated (p<0.001). Occurrence of CD28 abs is significantly higher in patients receiving interferons independent from the underlying disease (p<0.001). In vitro CD28 serum antibodies have an inhibitory effect on the CD28 receptor as they lead to reduced stimulation of Jurkat cells. Presence of CD28 was correlated with a higher risk of dying from melanoma (p = 0.043), but not with a significantly shortened overall survival or progression-free survival. CONCLUSION: Interferon therapy appears to induce the production of CD28 abs. In light of reports that these CD28 abs induce immunosuppressive Tregs and - as our data show - that they are inhibitors of CD28 receptor mediated stimulation, the continuation of therapies with interferons in melanoma patients developing CD28 antibodies should be critically reconsidered, since our data indicate a worse outcome of patients with CD28 abs.

Persistent accumulation of interferon-γ-producing CD8+CD56+ T cells in blood from patients with coronary artery disease.

OBJECTIVE: There is emerging evidence for CD8(+) T cell alterations in blood from patients with coronary artery disease (CAD). We examined whether the distribution and phenotype of CD8(+)CD56(+) T cells differed according to the clinical manifestation of CAD. METHODS: Patients with acute coronary syndrome (ACS, n = 30), stable angina (SA, n = 34) and controls (n = 36) were included. Blood was collected before and up to 12 months after referral for coronary investigation. CD8(+)CD56(+) T cells were assessed by flow cytometry for expression of surface markers, apoptosis, and intracellular expression of cytokines. RESULTS: The proportions of CD8(+)CD56(+) T cells were significantly higher in both ACS and SA patients compared with controls, and remained so after 3 and 12 months. This was independent of age, sex, systemic inflammation and cytomegalovirus seropositivity. CD8(+)CD56(+) T cells differed from CD8(+)CD56(-) T cells in terms of lower CD28 expression and fewer apoptotic cells. Both CD8(+) T cell subsets were positive for interferon (IFN)-γ and tumor necrosis factor, although IFN-γ was significantly more confined to the CD8(+)CD56(+) T cells. CONCLUSION: The persistent accumulation of CD8(+)CD56(+) T cells in ACS and SA patients share several features with immunological aging. It also contributes to a larger IFN-γ(+) pool in blood, and may thereby hypothetically drive the atherosclerotic process in a less favorable direction.

CD8+CD28-lymphocytes in peripheral blood and serum concentrations of soluble interleukin 6 receptor are increased in patients with Graves' orbitopathy and correlate with disease activity.

BACKGROUND: The extrathyroid, orbital manifestation of Graves' disease (GD)--Graves' orbitopathy (GO)--presents a difficult clinical problem. The immunological status of GO patients is still under investigation. The aim of this study was to assess the serum concentration of interleukin 6 (IL-6), soluble interleukin 6 receptor (sIL-6R), and CD8+CD28- lymphocytes in GO patients and to evaluate if these parameters were associated with disease activity. PATIENTS: Thirty-nine patients (29 women and 10 men, aged 24-71, mean 50.18) with newly diagnosed GD were enrolled in the study. Active GO was diagnosed in 20 patients. The control group included 12 healthy individuals. METHODS: Serum concentrations of IL-6 and sIL-6R were estimated by ELISA. Percentages of CD8+CD28- lymphocytes in peripheral blood were assessed by flow cytometry. RESULTS: Mean serum IL-6 and sIL-6R concentrations were significantly higher in all GD patients and in GO and non-GO patients than in normal controls. In all GD patients and the non-GO group, serum IL-6 and sIL-6R concentrations were significantly reduced after efficient treatment. In GO patients, only serum sIL-6R concentration was significantly lower after efficient treatment. In all GD patients, the mean percentage of CD8+CD28- lymphocytes was significantly lower after efficient treatment. In GO patients, the mean percentage of CD8+CD28- lymphocytes was significantly higher than in the non-GO group or in normals. Moreover, in the GO group, the mean percentage of CD8+CD28- lymphocytes was significantly lower after treatment. CONCLUSION: Our results have shown that CD8+CD28- lymphocyte percentage in peripheral blood and serum concentration of sIL-6R are increased in GO patients and correlate with disease activity.

Peripheral blood lymphocyte dynamics and viral kinetics in patients with chronic active hepatitis B virus infection treated by tenofovir.

BACKGROUND/AIMS: We investigated serum viral kinetics and peripheral blood lymphocyte dynamics in chronic hepatitis B patients during the first year of tenofovir therapy. METHODOLOGY: Fifteen patients, naive to any kind of previous antiviral therapy, were included in this study. The patients received tenofovir daily 245mg for 48 weeks. Fifteen age and gender compatible healthy subjects were enrolled as the control group. Clinical, biochemical, immunological and virological parameters were assessed at baseline, then at the first, third, sixth and twelfth months. RESULTS: CD4+CD25+FOXP3+ nTregs percentages were significantly higher in the study group than that of healthy controls, CD4+CD28+ and CD4+CD38+ T cell percentages were significantly lower in the study group than those of control group (p<0.001). Twelve cases had undetectable HBV DNA levels after the one year therapy. We determined that there was an increase of the CD28+co-stimulator molecule on both the CD4+ and CD8+ T cells while a decrease of the CD8+CD38+ T cells, CD4+CD38+ T cells and CD4+CD25+FOXP3+ nTregs, in patients with tenofovir treatment, but only CD4+CD25+FOXP3+ nTregs were statistically significant. CONCLUSIONS: We found that both viral load and CD4+CD25+FOXP3+ nTreg percentages decreased significantly in patients with chronic hepatitis B virus infection during 1 year course of tenofovir treatment.

Human peripheral blood CD8+ CD28- T cells of renal allograft recipients do not express FOXP3 protein.

INTRODUCTION: In recent studies, the FOXP3 molecule has been suggested to be a marker of a suppressor subset of human CD8+ CD28- T cells based on correlations between the level of its mRNA and allograft function. Because this transcriptional factor produces a protein, we suggest that these correlations should focus on the FOXP3 protein. The aim of our study was to evaluate whether FOXP3 protein was present in cells of the CD8+ CD28- population in the peripheral blood of renal allograft recipients and whether the level of CD8+ CD28- FOXP3+ cells correlated with allograft function. METHODS: The study was performed on 30 renal allograft recipients with uneventful stable courses (n=18) or biopsy-proven chronic rejection (n=12). The immunosuppression was based on cyclosporine (n=12) or rapamycin (n=9). Peripheral blood mononuclear cells isolated from recipient blood samples were labeled with anti-CD8 and anti-CD28 MAbs conjugated with fluorochromes. After incubation, washing, and labeling using a PE anti-human FOXP3 Kit, we determined the percentage of cells by flow cytometry. RESULTS: FOXP3 protein expression was not observed either in the CD8+ CD28- population, or the whole populations of CD8+ or CD28- cells among patient groups. CONCLUSIONS: The expression of FOXP3 protein in CD8+ CD28- cells seems to be of a questionable value as a diagnostic tool for allograft function, it is probably not a marker for the CD8+ CD28- T cell subset.

Gene expression profiling-based identification of CD28 and PI3K as new biomarkers for chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Currently, no reliable biomarkers are available to predict the onset or progression of cGVHD. Therefore, in this study, we collected peripheral blood mononuclear cells from four patients with cGVHD and four ones with non-GVHD after hematopoietic stem cell transplantation and employed Affymetrix GeneChip Human U133 Plus 2.0 microarrays to screen the genes differentially expressed in cGVHD versus non-GVHD groups, with the aim to identify potential clinical biomarkers to predict cGVHD risk or progression. Microarray analysis demonstrated that the expression of 3180 genes changed significantly in cGVHD versus non-GVHD, with 879 genes upregulated and 2301 genes downregulated. Among them we chose CD28 and PI3K as candidates for further verification. Flow cytometry and quantitative real-time polymerase chain reaction analysis confirmed the significant upregulation of CD28 and PI3K in samples from patients with cGVHD compared with patients with non-GVHD, respectively. In conclusion, our study suggested that the upregulation of CD28 and PI3K contributed to the onset and progression of cGVHD and provided evidence that CD28 and PI3K may serve as promising biomarkers for cGVHD.

Assessment of oxidative stress in lymphocytes with exercise.

This study investigated whether changes in the cellular composition of blood during exercise could partly account for observations of exercise-induced changes in lymphocyte oxidative stress markers. Markers of oxidative stress were assessed before and after 60 min of intense treadmill running. Samples were collected from 16 men (means ± SD: age 33 ± 13 yr; body mass index 23.8 ± 2.5 kg/m(2); maximal oxygen uptake 59.7 ± 5.2 ml·kg(-1)·min(-1)). Peripheral blood lymphocytes were assayed for protein carbonyl concentration, and plasma was assessed for lipid peroxides and antioxidant capacity. In a separate study, intracellular thiol concentration was determined in lymphocyte subsets from eight characteristically similar men by flow cytometry, of which T-cell memory populations were further identified on the basis of CD27, CD28, and CD45RA expression. Total lymphocyte protein carbonyls were transiently increased with exercise and returned to baseline within 15 min (P < 0.001). This change was accompanied by an increase in plasma lipid peroxides (P < 0.05) and total antioxidant capacity (P < 0.001). Correlation analyses showed that lymphocyte protein carbonyl content was not related to changes in the cellular composition of peripheral blood during exercise. Natural killer cells (CD3(-)CD56(+)) and late-differentiated/effector memory cells (CD4(+)/CD8(+)CD27(-)CD28(-)/CD45RA(+)), which mobilized most with exercise, showed high intracellular thiol content (P < 0.001). High thiol content suggests a lower oxidative load carried by these lymphocytes. Thus vigorous exercise resulted in a transient increase in lymphocyte oxidative stress. Results suggest this was unrelated to the alterations in the cellular composition of peripheral blood.