Peripheral CD4+CD28null T-cells as predictors of damage in systemic lupus erythematosus patients

OBJECTIVES

To determine whether the CD4+CD28null T-cells subpopulation predicts the occurrence of damage in SLE.

METHODS

This longitudinal study was conducted in consecutive SLE patients seen every six months in our Rheumatology Department since 2012. Patients in whom CD4+CD28null T-cells had been measured and who had at least one subsequent visit were included in the study. Survival analyses (univariable and multivariable Cox-regression models) were performed to determine the risk of overall and domain damage (as per the SLICC Damage Index - SDI) as a function of the frequency of this T-cell subpopulation. The multivariable model was adjusted for pertinent confounders. All analyses were performed using SPSS 21.0.

RESULTS

One hundred and nineteen patients were evaluated; their mean (SD) age was 43.5 (11.9) years, 113 (95.0%) were female. Disease duration was 7.8 (7.0) years, the SLEDAI 5.3 (4.1) and the SDI 1.0 (1.4). The percentage of CD4+CD28null T-cells was 17.4 (14.0). The mean follow-up was 2.1 (0.8) years, and the mean number of visits per patient 3.5 (1.1). Forty-six (38.7%) patients increase at least one SDI point. In the univariable and multivariable analyses, the percentage of CD4+CD28null predicted the occurrence of lung damage [HR: 1.042 (CI95%: 1.001-1.085); p=0.047 and HR: 1.099 (CI95%1.020-1.184); p=0.013, respectively] but neither the total SDI score nor all other SDI domain scores were predicted by the percentage of CD4+CD28null cells.

CONCLUSIONS

In SLE patients, CD4+CD28null T-cells predict the occurrence of new lung damage, independently of other risk factors but not of overall damage or damage on other domains.

Older men display elevated levels of senescence-associated exercise-responsive CD28null angiogenic T cells compared with younger men

Aging is associated with elevated cardiovascular disease risk. As a result of aging, endothelial dysfunction develops, partly due to a reduction in vascular regenerative ability. CD31+ T cells (angiogenic T cells; TANG ) possess highly angiogenic capabilities; however, these cells are significantly reduced in older populations. In addition, older populations possess significantly higher senescent and highly differentiated T-cell levels in circulation, and these are reported to be highly exercise responsive. We investigated whether older adults display greater levels of circulating senescent (CD28null ) TANG cells and whether these cells were more exercise responsive than CD28+ TANG cells. Young (18-25 years; n = 9) and older (60-75 years; n = 10) healthy men undertook a 30-min cycling bout at 70% V˙O2 peak, with circulating TANG cells (CD3+  CD31+  CD28+/null ; including CD4+ and CD8+ subsets) measured preexercise, postexercise, and 1 h post exercise by flow cytometry. Older adults displayed reduced basal levels of TANG cells (mean ± SEM: 410 ± 81 vs. 784 ± 118 cells·μL, P = 0.017), despite a greater proportion of these cells being CD28null (26.26 ± 5.08 vs. 13.36 ± 2.62%, P = 0.044). Exercise significantly increased the circulating number of TANG cells in both young and older men. However, in older men alone, exercise preferentially mobilized CD28null CD8+ TANG cells compared with CD28+ TANG cells (time × phenotype interaction: P = 0.022; Δ74 ± 29 vs. Δ27 ± 15 cells·μL, P = 0.059), with no such difference observed between these phenotypes in the young population. In conclusion, this is the first study to demonstrate that despite observing lower circulating numbers of TANG cells, older adults display greater levels of senescent TANG cells in comparison with younger individuals, and these cells are more exercise responsive than CD28+ TANG cells. Lower number of circulating TANG and greater levels of senescent-associated CD28null TANG may contribute to greater CVD risk with advancing age.

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.

Response to inhaled corticosteroids on serum CD28, quality of life, and peak expiratory flow rate in bronchial asthma

BACKGROUND

CD28 is a 44 kDa glycoprotein that is important in initiating T-cell responses and that results in increased T-cell proliferation and interleukin-2 production. This study estimated the serum CD28 levels in patients with asthma and evaluated the effect of inhaled corticosteroids (ICS) on the levels of CD28, the peak expiratory flow rate (PEFR), and quality of life (QOL).

METHODS

This prospective, open-label, observational study enrolled 40 adult patients with asthma of mild-to-moderate severity who were started on ICS and 40 healthy controls. Patients with bronchial asthma were evaluated for their serum CD28 level and QOL by using Mini Asthma Quality of Life Questionnaire scores, severity of symptoms, and PEFR at baseline and after 4 weeks.

RESULTS

The mean (standard deviation [SD]) serum CD28 concentration in patients with asthma was 107 ± 4.98 ng/mL, which was significantly elevated (p < 0.01) compared with the healthy individuals (37.67 ± 18.28 ng/mL). ICS treatment for 4 weeks reduced the mean (SD) serum CD28 levels to 40.9 ± 2.82 ng/mL. PEFR increased significantly, from 190.75 ± 10.55 to 263 ± 10.69 L/min (p < 0.01) after 4 weeks. Similarly, the mean (SD) Mini Asthma Quality of Life Questionnaire scores significantly increased, from 36.90 ± 10.31 on day 0 to 70.63 ± 11.56 on day 28 after ICS therapy (p < 0.01). A negative correlation between the elevations of serum CD28 levels was seen with QOL.

CONCLUSION

The serum CD28 concentration, a marker of inflammation, is increased in bronchial asthma and reduced by ICS therapy. ICS also improved QOL scores and objective clinical outcomes in patients with asthma.

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.

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.

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.

Differences in B7 and CD28 family gene expression in the peripheral blood between newly diagnosed young-onset and adult-onset type 1 diabetes patients

Type-1 diabetes (T1D) is a heterogeneous autoimmune disease, and there are pathogenetic differences between young- and adult-onset T1D patients. We hypothesized that the expressions of genes involved in costimulatory immune system pathways in peripheral blood are differently regulated in young- and adult-onset T1D. Study group I consisted of 80 children, adolescents, and young adults (age range 1.4-21.4 y; 31 controls and 49 T1D patients). Study group II consisted of 48 adults (age range 22.0-78.4 y; 30 controls and 18 T1D patients). The mRNA expression levels of CD86, CD28, CD25, CD226, CD40, BTLA, GITR, PDCD1, FoxP3, TGF-β, ICOS, sCTLA4, flCTLA4, and CD80 were measured in peripheral blood. Genetic polymorphisms (HLA haplotypes; rs231806, rs231775, and rs3087243 in CTLA4; rs763361 in CD226; and rs706778 in CD25) and T1D-associated autoantibodies were analyzed. In group I, there was significantly lower expression of CD226 in T1D patients than in the controls. In group II, there were significantly higher expression levels of CD86 and TGF-β in T1D patients than in the controls. In the T1D patients in group I, the upregulated CD80 expression correlated with the expression of both CTLA4 splice variants (sCTLA4 and flCTLA4). In contrast, in group II, upregulated CD86 correlated with TGF-β and CD25. In group I, the inhibitory CD80-CTLA4 pathway was activated, whereas, in group II, the activation CD86-CD28 pathway and TGF-β production were activated. These results emphasize the differences between young-onset and adult-onset T1D in the regulation of costimulatory pathways. These differences should be considered when developing novel treatments for T1D.

Immunoregulatory molecules in patients with gestational diabetes mellitus

Induction of maternal-fetal immune tolerance is essential for the development of normal pregnancy. Impaired expression of costimulatory molecules may lead to intense inflammatory reaction, a mechanism involved in the pathophysiology of gestational diabetes mellitus (GDM). The aim of this study was to investigate whether immunoregulatory molecules are involved in the physiopathology of GDM. This case-control study included 30 healthy pregnant women and 20 GDM patients. Flow cytometry was used to assess peripheral blood T subpopulations (CD4(+) and CD8(+)), the expression of immunoregulatory molecules (CD28, ICOS, CTLA-4, and PD-1) and activation markers (CD69 and HLA-DR). Compared to healthy women, GDM patients had a significantly higher frequency of CD4(+)CD69(+) and CD8(+)CD69(+) T cells; only patients with insulin-treated GDM had increased numbers of CD4(+)HLA-DR(+) T cells. We also observed significantly higher percentages of CD4(+)CD28(+)HLA-DR(+), CD3(+)CD4(+)ICOS(+), CD3(+)CD4(+)PD-1(+), CD8(+)CD28(+)CD69(+), CD8(+)CD28(+)HLA-DR(+), CD8(+)CTLA-4(+)HLA-DR(+), and CD3(+)CD8(+)ICOS(+) T cells and lower frequency of CD3(+)CD4(+)CTLA-4(+), CD3(+)CD8(+)CTLA-4(+), and CD8(+)ICOS(+)HLA-DR(+) T cells in GDM patients compared to healthy pregnant women. This first study assessing costimulatory molecules in GDM patients shows that these patients have exacerbated markers of T cell activation along with CTLA-4 deficiency, findings that indicate that the maternal-fetal tolerance is compromised in these patients.

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.

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)-β. Neutralization of TGF-β 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.

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.

CD 28 gene polymorphism and plasma concentration of soluble CD 28 in Iranian patients with visceral leishmaniasis

In visceral leishmaniasis (VL), the development of protective immunity is associated with expansion of leishmania-specific T-cell responses. Because of the essential role of CD28 in the effectiveness of T-cell activation, this study was carried out to investigate the CD28 gene polymorphism and plasma levels of soluble (s) CD28 molecule in Iranian patients with VL. Plasma concentrations of CD28 in 88 patients with VL, 132 individual with subclinical leishmaniasis, and 100 seronegative healthy controls were measured by enzyme-linked immunosorbent assay. Genotyping of CD28 gene polymorphism was performed by polymerase chain reaction based allotyping method using allele-specific primers for C or T at intron 3 position +17 in three groups. The frequency of CC genotype was significantly higher in subclinical VL patients (42.4%) than active VL group (27.3%) and healthy controls (16%) (P<0.001). Also, the frequency of allele C among subclinical VL group (57.6%) was significantly higher than active VL (40.9%) and control groups (34%) (p=0.003). No significant differences were observed between the plasma levels of sCD28 in three groups. Our findings suggest that the CD28 gene may have significant role in the protection of active VL in the Iranian population.

Evaluation of the effect of IL-22 on human cord blood CD4+ T cells

IL-22 is a member of IL-10 cytokine family which is believed to play an important role in inflammatory responses. IL-22 has similarities with IL-10 including conserved sequences with IL-10. IL-22 receptor is also comprised of two chains known as L-22R1 and L-10R2; supporting the speculation that the two cytokines may have similar effects. The aim of this study was to shed some light on the biological activity of IL-22 upon the cord blood CD4+CD25- T cells. In this research, cord blood T CD4+CD25- cells were cultured in presence of anti CD2/CD3/CD28 coated beads, IL-2 and IL-22 for two weeks at 37 degrees C and 5% CO2. Flow cytometry analysis showed that IL-22 has no effect upon CD25 and Foxp3 expression. Also, the results indicated that IL-22 is not involved in CD4+ T cell proliferation. Moreover, the results of suppression assay did not show any suppression effect on the cultured T cells. Thus, it seems that umbilical cord blood T cells probably do not express IL-22R1 on their surface.

Antisense anti IGF-I cellular therapy of malignant tumours: immune response in cancer patients

The treatment of cancer by antisense anti-IGF-I cellular therapy inducing immune response has evoked interest among many promising strategies. Here, we reported some results obtained from patients with cancer, mainly glioblastoma treated by this strategy, which was also extended to patients with colon carcinoma, ovary cystadenocarcinoma and prostate adenocarcinoma. It was shown that, in the phase I of clinical trial, patients vaccinated with their own tumour cells treated by antisense IGF-I presented a slight increase of temperature. Their peripheral blood lymphocytes showed a shift in the percentage of CD8 effector cells as judged by expression of cell surface markers CD8+ CD28+. Particularly, in two treated patients with glioblastoma, the survival time was 19 and 24 months respectively in comparison to the range of 12 to 15 months observed in the case of classical treatment such as surgery, radiation or chemotherapy. These results, although preliminary, gave indication that the reported strategy could deserve consideration owing to its safety. Furthermore, the increase in the percentage of peripheral blood monomorphonucleated cells (PBMNCs) with effector phenotype, i.e., CD8+ CD28+ in vaccinated patients might explain their prolonged survival time.

Peripheral blood gene expression of B7 and CD28 family members associated with tumor progression and microscopic lymphovascular invasion in colon cancer patients

PURPOSE

To associate the global gene expression of B7/CD28 family transcripts with pathologic features of colon cancer, we determined the B7/CD28 family transcripts in peripheral blood mononuclear cells (PBMCs) from normal subjects and patients with adenomatous polyps and colon cancer, and correlated the results with pathologic features of colon cancer.

METHODS

PBMCs from age-matched normal subjects and patients with adenomatous polyps and colon cancer were analyzed for peripheral blood transcripts (PBTs) of B7/CD28 family using real-time PCR. Differences in expression levels of B7/CD28 PBTs across all cancer stages and between colon cancer patients with or without microscopic lymphovascular invasion (LVI) were analyzed.

RESULTS

The results showed a significant upregulation of PBTs of co-inhibitory molecules such as B7-H3 and PD-1 and a significant PBT downregulation of co-stimulatory molecules including CD28 and ICOS in colon cancer patients. Furthermore, the increase of B7-H3 PBT was strongly associated with tumor invasion (P = 0.025) and advanced TNM stages (P = 0.019), whereas the decline of co-stimulatory ligand B7-H2 PBT was related to regional lymph node metastasis (P = 0.028) and aggressive tumor invasion (P = 0.031). In addition, the ratios of PBT expression of CD28 family to B7 family such as CTLA-4 to B7-H2 and PD-1 to B7-H2 were significantly higher in colon cancer patients with microscopic LVI than in those without LVI (P = 0.001 and P = 0.016, respectively).

CONCLUSIONS

Our results suggest that B7/CD28 family PBTs may serve as valuable markers reflecting the pathological features of colon cancer.

[Influence of electroacupuncture of Guanyuan (GV 4) and Zusanli (ST 36) on the immune function of T cells in aging rats]

OBJECTIVE

To observe the influence of electroacupuncture (EA) on T cell immunologic function in the aged rats so as to reveal its underlying mechanism in anti-aging effect.

METHODS

Fifty SD rats (half male and half female) were randomly divided into normal control (young rats), aging model (model), EA group, immunosuppression (IS), and EA+ IS groups. Aging model (in the late 4 groups) was duplicated by subcutaneous injection of D-galactose for 40 days. Guanyuan (CV 4) and bilateral Zusanli (ST 36) were punctured and stimulated electrically (2 Hz, 1 mA), 15 min every time, six times a week and for four weeks. IS model was induced by i. p. i. of cytoxan (60 mg/kg) after 26 and 27 days' EA treatment. Splenetic T lymphocyte proliferation index was assayed by Methylthiazolyldiphenyl-tetrazolium bromide (MTT) chromatometry. IL-2/IL-2 receptor (R) expression level of T cells was measured by enzyme linked immunosorbent assay (ELISA). CD8+ CD28(+) -T cell subset fluorescence intensity was detected by flow cytometry.

RESULTS

Compared with normal control group, the splenetic T lymphocyte proliferation index, IL-2 and IL-2R expression levels, and CD8+ CD28(+) -T cell density in model and IS groups decreased significantly (P < 0.01). In comparison with model group, the abovementioned indexes in EA and EA + IS groups increased significantly (P < 0.01), and those indexes levels of EA + IS group were also significantly higher than those in IS group ( P < 0.05, P < 0.01). Comparison between EA and EA+ IS groups showed that CD8+ CD2+ T cell expression of the later group was significantly lower than that in EA group (P < 0 05). No significant differences were found between EA and EA + IS groups in T cell proliferation rate and IL-2 and IL-2R expression levels (P > 0.05)

CONCLUSION

EA of CV 4 and ST 36 induced upregulation of T cell proliferation and IL-2/IL-2R, and CD8+ CD(+)28 -T cell may contribute to its antiaging and immuno-enhancement effects in the aged rats.

Increased percentage of CD8+CD28- suppressor lymphocytes in peripheral blood and skin infiltrates correlates with advanced disease in patients with cutaneous T-cell lymphomas

INTRODUCTION

T cells with the CD8+CD28- phenotype are CD8+ lymphocytes with regulatory function. Their increased numbers were observed in infections, autoimmune and neoplastic diseases, and in elderly healthy individuals. CD8+CD28- lymphocyte levels in patients with cutaneous T-cell lymphoma (CTCL) has not yet been described. The aim of the study was to determine their levels in these patients' peripheral blood and cutaneous infiltrates and their relation to the clinical stage of disease.

MATERIAL/METHODS

Forty-one untreated patients, 26 males and 15 females, with CTCL were enrolled in the study. CD8+CD28- lymphocyte levels were determined by flow cytometry in peripheral blood and by immunochemistry in skin infiltrates.

RESULTS

The percentage of CD8+CD28- lymphocytes in the peripheral blood of the patients was significantly higher than in the controls. Patients with advanced disease displayed a higher percentage of CD8+CD28- lymphocytes in the peripheral blood and skin than did the individuals with early stages of the disease. Moreover, positive correlations between CD8+CD28- lymphocyte level in peripheral blood and age, clinical stage, and the levels in the skin infiltrates was revealed. Additionally, the percentage of CD8+CD28- T cells in the skin infiltrates correlated positively with age and clinical stage of the disease.

CONCLUSIONS

These data suggest that CD8+CD28- lymphocytes play an important role in the development of immunotolerance in the progression of cutaneous T-cell lymphoma.

Skewed distribution of proinflammatory CD4+CD28null T cells in rheumatoid arthritis

Expanded populations of CD4+ T cells lacking the co-stimulatory molecule CD28 (CD4+CD28null T cells) have been reported in several inflammatory disorders. In rheumatoid arthritis, increased frequencies of CD4+CD28null T cells in peripheral blood have previously been associated with extra-articular manifestations and human cytomegalovirus (HCMV) infection, but their presence in and contribution to joint manifestations is not clear. In the present article we investigated the distribution of CD4+CD28null T cells in the synovial membrane, synovial fluid and peripheral blood of RA patients, and analysed the association with erosive disease and anti-citrullinated protein antibodies. CD4+CD28null T cells were infrequent in the synovial membrane and synovial fluid, despite significant frequencies in the circulation. Strikingly, the dominant TCR-Vbeta subsets of CD4+CD28null T cells in peripheral blood were often absent in synovial fluid. CD4+CD28null T cells in blood and synovial fluid showed specificity for HCMV antigens, and their presence was clearly associated with HCMV seropositivity but not with anti-citrullinated protein antibodies in the serum or synovial fluid, nor with erosive disease. Together these data imply a primary role for CD4+CD28null T cells in manifestations elsewhere than in the joints of patients with HCMV-seropositive rheumatoid arthritis.

Factors involved in the generation of memory CD8+ T cells in patients with X-linked lymphoproliferative disease (XLP)

We have analysed the phenotype of T lymphocytes in two X-linked lymphoproliferative disease (XLP) patients with the same SH2D1A mutation differing in initial exposure to Epstein-Barr virus (EBV) and treatment. While memory T lymphocytes (with low CCR7 and CD62L expression) prevailed in both XLP patients, in patient 9, who developed acute infectious mononucleosis (AIM) and received B cell ablative treatment, the predominant phenotype was that of late effector CD8 T cells (CD27-, CD28-, CCR7-, CD62L-, CD45 RA+, perforin+), while in patient 4 (who did not suffer AIM) the prevalent phenotype of CD8 T lymphocytes was similar to that of normal controls (N) or to that of adult individuals who recovered from

AIM

CD27+ , CD28+, CCR7-, CD62L-, CD45 RO+ and perforin-. CD57 expression (related to senescence) was also higher in CD8 T cells from patient 9 than in patient 4, AIM or N. Persistently high EBV viral load was observed in patient 9. The results obtained from this limited number of XLP patients suggest that events related to the initial EBV encounter (antigen load, treatment, cytokine environment) may have more weight than lack of SH2D1A in determining the long-term differentiation pattern of CD8 memory T cells.

BY55/CD160 cannot be considered a cytotoxic marker in cytomegalovirus-specific human CD8(+) T cells

CD160/BY55 is a glucosyl-phosphatidylinositol (GPI)-anchored cell membrane receptor that is expressed primarily in natural killer (NK) cells. Its presence in CD8(+) T lymphocytes is considered to be a marker of cytotoxic activity, although there are few data in this regard. In the present work, we analysed the expression of CD160 in subpopulations of cytomegalovirus (CMV)-specific CD8(+) T cells. Subpopulations were defined by CD28 and CD57 expression and exhibited varying degrees of differentiation and cytotoxic potential, as evaluated by the expression of perforin, interferon (IFN)-gamma and interleukin (IL)-7Ralpha/CD127. We included subjects with different intensities of anti-viral immune response. Results showed that the terminally differentiated CD28(-) CD57(+) subset displaying the highest level of perforin expressed CD160 at a level similar to that of memory CD28(+) CD57(-)perforin(-) cells. A comparison of the expression of perforin in CD160(+) cells versus CD160(-) cells showed that expression was significantly higher in the absence of CD160. Interestingly, the CMV-specific CD8(+) T cell subset from a patient with ongoing CMV reactivation did not begin to express CD160 until day +92 of the follow-up period. Taken together, our data show that CD160 cannot be considered a cytotoxic marker in CMV-specific CD8(+) T cells.

The soluble forms of CD28, CD86 and CTLA-4 constitute possible immunological markers in patients with abdominal aortic aneurysm

OBJECTIVE

The T cell co-stimulatory factors CD28 and CTLA-4 and their ligands CD80 and CD86 occur as receptors on T cells and antigen-presenting cells and also in soluble forms in the circulation. We determined the levels of soluble co-stimulatory molecules in patients with abdominal aortic aneurysm (AAA) and normal individuals. We further correlated these soluble co-stimulatory molecules to other clinical parameters of importance such as age of the patient, presence of hypertension, size of the aneurysm and levels of matrix metalloproteinases-9 and C-reactive protein.

DESIGN, SETTING, SUBJECTS

This case-control study was designed to quantify the circulating levels of soluble co-stimulatory molecules by an in-house enzyme linked immunosorbent assay. A total of 314 subjects participated in the study including 100 patients and 214 normal controls. The statistical analysis was performed by Mann-Whitney test and Spearman's correlation rank test.

RESULTS

Our results show increased plasma levels of sCD28, sCD86 (P = 0.0001) and decreased plasma levels of sCTLA-4 (P = 0.0018) in the patients compared with normal individuals. The levels of these factors were not related to the age of the patient, size of aneurysm or levels of C-reactive protein in plasma. There was, however, a significant inverse relationship between the concentrations of sCTLA-4 and sCD80 with matrix metalloproteinase-9.

CONCLUSIONS

We suggest that soluble co-stimulatory molecules serve as biomarkers for the estimation of immune activation in AAA patients.

Soluble costimulatory factors sCD28, sCD80, sCD86 and sCD152 in relation to other markers of immune activation in patients with myasthenia gravis

The costimulatory factors CD28, CD80, CD86 and CD152 needed to start and turn off an immune response are present as membrane receptors and soluble proteins. There was no difference in the serum levels of soluble costimulatory molecules in 153 healthy controls and 118 patients with myasthenia gravis. However, we could confirm that the soluble forms of ICAM-1 and CD25 were increased in patients. The concentrations of the soluble costimulatory proteins seemed to be rather constant in individual patients, despite changes in clinical presentation. Thus, the soluble costimulatory factors do not seem to constitute reliable markers for disease activity in myasthenia gravis.

A subset of functional effector-memory CD8+ T lymphocytes in human immunodeficiency virus-infected patients

CD8(+) T cells provide protective immune responses via both cytolytic and non-cytolytic mechanisms in subjects infected with human immunodeficiency virus (HIV). In the present study, we investigated the CD28 expression of CD8(+) T cells present in the peripheral blood lymphocyte subset isolated from chronically HIV-infected subjects. Using flow cytometric analysis, a continuous spectrum of CD28 intensity ranging from negative to high, which could be separated into CD28-negative, intermediate (int) and high, was seen for CD8(+) T cells. Our study focused mostly on the CD28(int) CD8(+) T cells. The CD28(int) CD8(+) T cells are CD57(-) CD27(+) CD45RO(+) CD45RA(-) CCR7(low) CD62L(int). The proliferative capacity of CD28(int) CD8(+) T cells was intermediate between those of CD28(-) CD8(+) T cells and CD28(high) CD8(+) T cells. The CD28(int) CD8(+) T cells are specific for HIV, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) antigens as measured by human leucocyte antigen pentamer binding and produce both intracellular interferon-gamma and tumour necrosis factor-alpha in response to their cognate viral peptides. The CD28(int) CD8(+) T cells have HIV-specific, CMV-specific and EBV-specific cytotoxic activity in response to their cognate viral peptides. These findings indicate that a subset of functional effector-memory CD8(+) T cells specific for HIV, CMV and EBV antigens may contribute to an efficient immune response in HIV-infected subjects.

Effector T lymphocytes in well-nourished and malnourished infected children

The mechanisms involved in impaired immunity in malnourished children are not well understood. CD4(+) CD62L(-) and CD8(+) CD28(-) do not express the naive cell markers CD62L and CD28, suggesting that they function as effector T cells. Using a flow cytometry-based analysis we examined the proportions of CD4(+) CD62L(-) and CD8(+) CD28(-) T cell subsets in well-nourished infected (WNI) and malnourished infected (MNI) children. Here we report that WNI children had a higher percentage of CD4(+) CD62L(-) (11.1 +/- 1.0) and CD8(+) D28(-) (40.2 +/- 5.0) T cell subsets than healthy (6.5 +/- 1.0 and 23.9 +/- 4.8) and MNI children (7.4 +/- 1.1 and 23.1 +/- 6.2, respectively) (P < 0.5). Data suggest that WNI children respond efficiently against pathogenic microbes. In contrast, relatively low numbers of circulating of CD4(+) CD62L(-) and CD8(+) CD28(-) T cells in MNI children may represent an ineffective response to infection. Levels of effector T cells in children with gastrointestinal infections versus those suffering from respiratory infections were also significantly different within the WNI group. While WNI children with gastrointestinal infections had higher absolute and relative values of CD8(+), and CD8(+) CD28(-) T subsets, by those with respiratory infections had higher values of CD4(+) lymphocytes. However, due to the small number of subjects examined, our results in WNI children should be interpreted with caution and confirmed using a larger sample size. Our data suggest that altered expression of CD62L and CD28 receptors may contribute to impaired T cell function observed in MNI children.

Soluble CTLA-4 in autoimmune thyroid diseases: relationship with clinical status and possible role in the immune response dysregulation

CTLA-4 molecule, expressed by activated T and B lymphocytes, transduces an inhibitory signal. Increasing evidence showed CTLA-4 gene as an important susceptibility locus for autoimmune endocrinopathies and other autoimmune disorders. The aim is to evaluate the augmented sCTLA-4 serum levels in different autoimmune thyroid diseases when compared with normal donors or with non-autoimmune hyperthyroidism and to investigate the functional activities and suggest the possible pathogenetic role of sCTLA-4. We demonstrate the presence of a soluble form of CTLA-4 in 59/90 sera from patients with autoimmune thyroid diseases (both Graves' disease and autoimmune thyroiditis). sCTLA-4 levels were not related to specific clinical manifestations, such as clinical thyroid status (hypo- or hyperthyroidism), circulating thyroid hormones, or other clinical features (ophthalmopathy). sCTLA-4 production does not seem to be affected by disease evolution during time. We showed that sCTLA-4 from sera of patients with thyroid autoimmunity is able to bind its physiological ligands CD80/CD86 and displays functional activities on different in vitro systems (T-cell proliferation induced by specific soluble antigens, bi-directional mixed lymphocyte reaction). In conclusion, we demonstrate an increment of sCTLA-4 in serum of patients with autoimmune thyroid diseases. Its possible pathogenetic role during autoimmune processes can be speculated: sCTLA-4 can specifically inhibit the early T-cell activation by blocking the interaction of CD80/CD86 with the co-stimulatory receptor CD28. Conversely, higher levels of sCTLA-4 could compete with membrane-bound CTLA-4 for CD80/CD86, in later T lymphocytes activation phase, causing a reduction of inhibitory signaling.

CD80/CD28 co-stimulation in human brucellosis

Despite treatment, 10-30% of brucellosis patients develop chronic disease, characterized by atypical clinical picture and/or relapses. A defective T helper 1 (Th1) response and a low [corrected] percentage of CD4(+)/CD25(+) cells have been described in chronic brucellosis patients. CD80/CD28 co-stimulation is critical for an efficient Th1 response and has not been studied previously in human brucellosis. In order to investigate the role of CD80/CD28 co-stimulation, 13 acute brucellosis patients (AB), 22 chronic brucellosis patients (CB, 12/22 relapsing type-CB1 and 10/22 atypical type-CB2), 11 'cured' subjects and 15 healthy volunteers (controls) were studied. The percentage of CD4(+)/CD28(+) T lymphocytes and CD14(+)/CD80(+) monocytes were analysed by flow cytometry both ex vivo and after phytohaemagglutinin (PHA)-stimulation with or without heat-killed Brucella abortus (HkBA). Ex vivo analysis showed no differences between all groups studied. PHA stimulation up-regulated the percentage of CD80(+) monocytes in AB compared to 'cured' subjects and controls (P < 0.001), although the proportion of CD4(+)/CD28(+) cells did not alter. A higher percentage of CD80(+) monocytes was observed in the CB1 subgroup, compared to AB, 'cured' subjects and controls (P = 0.042, < 0.001 and < 0.001, respectively). CB2 was characterized by a lower percentage of CD80(+) monocytes in comparison to CB1 (P = 0.020). HkBA in PHA cultures down-regulated the percentage of CD80(+) monocytes compared to PHA alone in all groups, especially in AB and CB patients (P < 0.001 and P = 0.007, respectively). In conclusion, the diminished percentage of CD4(+)/CD25(+) T cells in CB is not associated with inadequate CD80/CD28 co-stimulation. We speculate that differential frequency of CD80(+) monocytes after PHA stimulation could serve as a qualitative parameter of disease status, related to the different clinical forms of chronic brucellosis.

Chronic Epstein-Barr virus-related hepatitis in immunocompetent patients

AIM: To investigate reactivated Epstein-Barr virus (EBV) infection as a cause for chronic hepatitis.

METHODS: Patients with occasionally established elevated serum aminotransferases were studied. HIV, HBV and HCV-infections were excluded as well as any other immunosuppressive factors, metabolic or toxic disorders. EBV viral capsid antigen (VCA) IgG and IgM, EA-R and EA-D IgG and Epstein-Barr nuclear antigen (EBNA) were measured using IFA kits. Immunophenotyping of whole blood was performed by multicolor flow cytometry. CD8⁺ T cell responses to EBV and PHA were determined according to the intracellular expression of IFN-γ.

RESULTS: The mean alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGTP) values exceeded twice the upper normal limit, AST/ALT ratio < 1. Serology tests showed reactivated EBV infection in all patients. Absolute number and percentages of T, B and NK cells were within the reference ranges. Fine subset analysis, in comparison to EBV⁺ healthy carriers, revealed a significant decrease of naive T cells (P < 0.001), accompanied by increased percentage of CD45RA^- (P < 0.0001), and terminally differentiated CD28^-CD27^-CD8⁺ T cells (P < 0.01). Moderately elevated numbers of CD38 molecules on CD8⁺ T cells (P < 0.05) proposed a low viral burden. A significantly increased percentage of CD8⁺ T cells expressing IFN-γ in response to EBV and PHA stimulation was registered in patients, as compared to controls (P < 0.05). Liver biopsy specimens from 5 patients revealed nonspecific features of low-grade hepatitis.

CONCLUSION: Chronic hepatitis might be a manifestation of chronic EBV infection in the lack of detectable immune deficiency; the expansion of CD28^-CD27^- and increase of functional EBV-specific CD8⁺ T cells being the only surrogate markers of viral activity.

Circulating gamma delta T cells in response to Salmonella enterica serovar enteritidis exposure in chickens

gammadelta T cells are considered crucial to the outcome of various infectious diseases. The present study was undertaken to characterize gammadelta (T-cell receptor 1(+) [TCR1(+)]) T cells phenotypically and functionally in avian immune response. Day-old chicks were orally immunized with Salmonella enterica serovar Enteritidis live vaccine or S. enterica serovar Enteritidis wild-type strain and infected using the S. enterica serovar Enteritidis wild-type strain on day 44 of life. Between days 3 and 71, peripheral blood was examined flow cytometrically for the occurrence of gammadelta T-cell subpopulations differentiated by the expression of T-cell antigens. Three different TCR1(+) cell populations were found to display considerable variation regarding CD8alpha antigen expression: (i) CD8alpha(+high) TCR1(+) cells, (ii) CD8alpha(+dim) TCR1(+) cells, and (iii) CD8alpha(-) TCR1(+) cells. While most of the CD8alpha(+high) TCR1(+) cells expressed the CD8alphabeta heterodimeric antigen, the majority of the CD8alpha(+dim) TCR1(+) cells were found to express the CD8alphaalpha homodimeric form. After immunization, a significant increase of CD8alphaalpha(+high) gammadelta T cells was observed within the CD8alpha(+high) TCR1(+) cell population. Quantitative reverse transcription-PCR revealed reduced interleukin-7 receptor alpha (IL-7Ralpha) and Bcl-x expression and elevated IL-2Ralpha mRNA expression of the CD8alphaalpha(+high) gammadelta T cells. Immunohistochemical analysis demonstrated a significant increase of CD8alpha(+) and TCR1(+) cells in the cecum and spleen and a decreased percentage of CD8beta(+) T cells in the spleen after Salmonella immunization. After infection of immunized animals, immune reactions were restricted to intestinal tissue. The study showed that Salmonella immunization of very young chicks is accompanied by an increase of CD8alphaalpha(+high) gammadelta T cells in peripheral blood, which are probably activated, and thus represent an important factor for the development of a protective immune response to Salmonella organisms in chickens.

HBV and HCV infections and acute rejection differentially modulate CD95 and CD28 expression on peripheral blood lymphocytes after liver transplantation

Hepatitis B virus (HBV) and hepatitis C virus (HCV) generally reinfect liver graft early posttransplantation and lead to poorer graft and patient survivals. In the present study the influence of acute rejection (AR), HBV and HCV infections, and human leukocyte antigen (HLA) class-I compatibility on the expression of CD28 (in 237 liver recipients) and CD95 (in 114 liver recipients) on peripheral blood cells were evaluated by flow cytometry during the first month after transplantation. HBV/HCV infections induced strong CD95 upregulation on CD3+ lymphocytes. Maximal CD95 upmodulation was found in infected recipients showing partial HLA class-I compatibility. AR and virus reinfection could be distinguished because CD28 was upregulated on CD4+ lymphocytes only in recipients with AR, irrespective of their status regarding HBV/HCV infections. In conclusion, cytometric co-evaluation of CD95 and CD28 expression on peripheral blood lymphocytes could be useful to discriminate AR from cellular activation induced by viral reinfection of the liver graft.

Plasma concentrations of soluble CTLA-4, CD28, CD80 and CD86 costimulatory molecules reflect disease severity of acute asthma in children

Recent studies have demonstrated an elevation of plasma soluble costimulatory molecules B7.1 (CD80) and B7.2 (CD86), and their T lymphocyte counter receptors cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and CD28 in asthmatic patients. We hypothesized that these costimulatory molecules may reflect the severity of asthma and investigated the longitudinal changes of these soluble costimulatory molecules, and their clinical significance in children with an asthmatic exacerbation. Sixteen children hospitalized for asthmatic exacerbation were recruited and treated with systemic corticosteroid (CS) for 5 days. Plasma total Immunoglobulin E (IgE) and eosinophil cationic protein (ECP) concentrations were measured by microparticle immunoassay and fluorescence enzyme immunoassay, respectively. Soluble CTLA-4 (sCTLA-4), sCD28, sCD80, and sCD86 concentrations in plasma were measured by enzyme-linked immunosorbent assay, and their relationships with asthma severity, total IgE, ECP concentrations, and blood eosinophil count were analyzed. Plasma sCTLA-4, sCD28, sCD80, and sCD86 concentrations in patients were highest during the acute attack. They decreased significantly with a parallel increase of peak expiratory flow rate (PEFR) after CS treatment (all P < 0.05). Plasma sCTLA-4, sCD28, and sCD86 concentrations of patients at recruitment were inversely correlated with PEFR, whereas plasma sCD28 and sCD86 concentrations correlated positively with eosinophil count and plasma ECP concentration (all P < 0.05). Although there was no such correlation with IgE concentration, sCD28 was correlated very significantly with eosinophil count (r = 0.83, P < 0.0001). In conclusion, plasma sCTLA-4, sCD28, sCD86, and sCD80 concentrations may reflect the severity of acute asthma and more studies on larger cohorts are needed to assess whether these markers are useful for assessing asthmatic exacerbation in children.

Intraindividual variability and the effect of acute illness on immune senescence markers

OBJECTIVES

To determine the intraindividual variability and effect of acute illness on two markers of immune senescence.

DESIGN

Cohort study with repeated measures.

SETTING

Clinical research center and emergency department at two academic medical centers.

PARTICIPANTS

Seventy-three subjects aged 65 and older enrolled in three groups: chronic underlying conditions but no acute illness, acutely ill with infection (community-acquired pneumonia), and acutely ill without infection.

MEASUREMENTS

CD16 density on polymorphonuclear neutrophils (PMNs) and the proportion of CD8+ T cells that express CD28 determined twice in the nonacutely ill group and three times (Days 0, 30, and 60) in the acute illness groups.

RESULTS

In the nonacutely ill group, PMN CD16 density demonstrated wide intraindividual variation, but there was a strong correlation for repeated measures of the percentage of CD8+ T cells expressing CD28 (correlation coefficient (r)=0.77, P<.001). Acute illness markedly affected both measures, regardless of whether the illness was due to infection; there was no correlation between measures obtained on Day 0 versus Day 30 for either immune marker. In contrast, a strong correlation existed between Day 30 and Day 60 values, particularly for CD8+/CD28+ percentage (r=0.58-0.86; P=.006 to <.001).

CONCLUSION

The percentage of CD8+ T cells that express CD28 is a highly reproducible marker of immune senescence. Although acute illness affects this marker, 30 to 60 days of convalescence appears adequate for it to return to baseline.

A phase 1 trial of donor lymphocyte infusions expanded and activated ex vivo via CD3/CD28 costimulation

Donor lymphocyte infusions (DLIs) induce potent graft versus tumor (GVT) effects for relapsed chronic myelogenous leukemia (CML) after allogeneic stem cell transplantation (SCT) but are disappointing for other diseases. Disease resistance can occur if donor T cells are not appropriately activated in vivo. Ex vivo T-cell activation might overcome disease-induced anergy and augment GVT activity. We performed a phase 1 trial of ex vivo-activated DLI (aDLI) for 18 patients with relapse after SCT. Activated donor T cells are produced through costimulation with anti-CD3- and anti-CD28-coated beads. Patients with aggressive malignancies received induction chemotherapy, and all patients received conventional DLI (median, 1.5 x 10(8) mononuclear cells/kg) followed 12 days later by aDLI. Activated DLI was dose escalated from 1 x 10(6) to 1 x 10(8) CD3+ cells per kilogram in 5 levels. Seven patients developed acute graft versus host disease (GVHD) (5 grade I-II, 2 grade III), and 4 developed chronic GVHD. Eight patients achieved complete remission, including 4 of 7 with acute lymphocytic leukemia (ALL), 2 of 4 with acute myelogenous leukemia (AML), 1 with chronic lymphocytic leukemia (CLL), and 1 of 2 with non-Hodgkin lymphoma (NHL). Four complete responders relapsed while 4 remain alive in remission a median 23 months after aDLI. Overall, 10 of 18 remain alive 11 to 53 months after aDLI. Adoptive transfer of costimulated activated allogeneic T cells is feasible, does not result in excessive GVHD, and may contribute to durable remissions in diseases where conventional DLI has been disappointing.

Preferential type 1 chemokine receptors and cytokine production of CD28- T cells in ankylosing spondylitis

OBJECTIVE

To examine serum levels of type 1 and type 2 chemokines and lymphocytic expression of chemokine receptors, and to compare the results with lymphocytic cytokine production in patients with ankylosing spondylitis (AS).

METHODS

Twelve patients with AS (mean (SD) age 44.9 (14.7) years) and 27 healthy controls (46.4 (12.8) years) were enrolled into the study. The expression of chemokine receptors (CCR-5, CXCR-3, CCR-4) and cytokines (interferon gamma (IFNgamma), interleukin (IL)2, IL4, IL10, tumour necrosis factor alpha (TNFalpha)) on CD28(+) and CD28(-) T cell subtypes was analysed by a three colour FACS technique of peripheral blood samples. Serum ELISAs were performed to detect the CCR-5 ligands CCL-5, CCL-3; the CXCR-3 ligands CXCL-10, CXCL-9; and the CCR-4 ligand, CCL-17 before and after administration of the TNFalpha blocking agent infliximab.

RESULTS

CD4(+)CD28(-) T cells had higher ratios of CXCR-3 to CCR-4 than CD4(+)CD28(+) T cells. Both, CD4(+) and CD8(+)CD28(-) T cells of patients with AS produced more IFNgamma, TNFalpha, and IL10 than their CD28(+) counterparts (p<0.05), and lacked the production of IL2 and IL4. Serum levels of CXCL-9 were increased in patients with AS to 59.2 pg/ml (34.1-730.5) compared with 32.5 pg/ml (20.0-79.5) in healthy controls (p = 0.016). The levels of both type 1 (CCL-5, CXCL-9) and type 2 chemokines (CCL-17) decreased under blockade of TNFalpha (p<0.05).

CONCLUSIONS

The profile of chemokine receptor expression and cytokine production by CD28(-) T cells suggests a type 1 immune reaction in AS, although IL10 is frequently produced by CD28(-) T cells. Treatment with TNFalpha blocking antibodies decreased both types of chemokines in patients' sera.

Increased expression of plasma and cell surface co-stimulatory molecules CTLA-4, CD28 and CD86 in adult patients with allergic asthma

The co-stimulatory interactions of the B7 family molecules CD80 and CD86 on antigen-presenting cells, together with their T cell counter receptors CD28 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), modulate T lymphocyte-mediated immune responses in a reciprocal manner. To investigate whether there is altered expression and the clinical significance of soluble co-stimulatory molecules in asthmatic patients, plasma concentrations of sCTLA-4, sCD28, sCD80 and sCD86 in 51 adult allergic asthmatic adults with or without steroid treatment, and 35 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay (ELISA). Cell surface expression of CTLA-4 and CD28 on peripheral blood mononuclear cells (PBMC) were analysed by flow cytometry. Results showed that the plasma sCTLA-4 concentration was significantly higher in all asthmatic patients while sCD28 and sCD86 concentrations were significantly higher in steroid and non-steroid treated asthmatic patients, respectively, compared with control subjects (all P < 0.01). Significantly increased cell surface expression of CD28 but not CTLA-4 on PBMC was found in asthmatic patients compared with controls (P < 0.05). The plasma concentration and cell surface expression of CTLA-4 were found to exhibit positive and significant correlations with those of CD28 (both P < 0.05). Serum total IgE concentration correlated positively and significantly with sCTLA-4 and sCD28 concentrations in allergic asthmatic patients (both P < 0.05). The increased expression of these soluble co-stimulatory molecules may reflect the dysregulation of T cell activation, thereby contributing to the immunopathogenesis of allergic asthma.

Circulating soluble CD28 in patients with Behçet's disease: relationship to clinical manifestations

OBJECTIVE

This study evaluates the presence of serum soluble CD28 (sCD28) in Behçet's disease (BD) and its relationship with clinical manifestations.

METHODS

Soluble CD28 concentration was determined by ELISA in 120 patients with BD (80 patients in active stage), 60 patients with rheumatoid arthritis (RA) and 60 healthy subjects.

RESULTS

Concentrations of sCD28 were significantly higher in patients with BD and RA than in healthy subjects. Patients with active BD expressed the highest level of sCD28 in serum. Soluble CD28 exhibited a drastic increase in active BD patients, compared to BD in remission. Soluble CD28 concentrations were higher in patients with active BD patients having vasculitis. Significant positive correlation was observed in a longitudinal study of 15 BD patients, between sCD28 and C-reactive protein.

CONCLUSION

Our study suggests that fluctuations of sCD28 in BD reflects disease activity and should be assessed in evaluating disease activity.

Aberrant production of soluble costimulatory molecules CTLA-4, CD28, CD80 and CD86 in patients with systemic lupus erythematosus

OBJECTIVE

The costimulatory interactions of the B7 family molecules CD80 and CD86 on antigen-presenting cells with their T-cell counter-receptors CD28 and CTLA-4 modulate T lymphocyte-mediated immune responses in a reciprocal manner. We investigated the possible aberrant production of soluble (s) forms of the T-cell costimulatory molecules CD80, CD86, CD28 and CTLA-4 in plasma of patients with systemic lupus erythematosus (SLE), an autoimmune disease arising from T-lymphocyte dysregulation.

METHODS

Plasma concentration and ex vivo production of soluble costimulatory molecules of 79 SLE patients with or without active disease and 40 sex- and age-matched healthy subjects were measured by enzyme-linked immunosorbent assay.

RESULTS

Plasma sCTLA-4, sCD28, sCD80 and sCD86 concentrations of all SLE patients were significantly higher than concentrations in control subjects (all P<0.01). These increases were observed even in patients with inactive disease [SLE Disease Activity Index (SLEDAI) <3]. Plasma sCTLA-4 concentration in all SLE patients correlated significantly with SLEDAI score (r = 0.228, P = 0.043). Upon mitogen treatment of peripheral blood mononuclear cells, the percentage increases in ex vivo production of sCD28 and sCD80 and the percentage decrease in sCTLA-4 release were all significantly smaller in SLE patients with active disease than in healthy subjects (P<0.01, P<0.05 and P<0.0001, respectively).

CONCLUSION

The aberrant production of soluble T-cell costimulatory molecules is important in the immunopathogenesis of SLE, which occurs by the dysregulation of T-lymphocyte costimulation. Plasma sCTLA concentration could potentially serve as a surrogate marker of SLE disease activity.

Elevation of plasma soluble T cell costimulatory molecules CTLA-4, CD28 and CD80 in children with allergic asthma

BACKGROUND

The surface expression of T cell costimulatory molecules CTLA-4 and CD28 and their counter-ligands, B7 molecules (CD80, CD86), is differentially induced for T cell activation and expansion in allergic asthma. However, the role of their soluble forms in plasma has not yet been elucidated. In this study, we investigated whether expression is altered and whether soluble costimulatory molecules are clinically relevant in asthmatic patients.

METHODS

Plasma concentrations of soluble CTLA-4 (sCTLA-4), CD28, CD80 and CD86 in 51 children with chronic allergic asthma with or without inhaled corticosteroid treatment, and 22 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay. Plasma total IgE concentration was measured using a microparticle immunoassay.

RESULTS

Asthmatic patients had higher logarithmic plasma total IgE concentration (IgE(log)) than healthy subjects (p < 0.0001). In non-steroid-treated patients, plasma sCTLA-4, sCD28 and sCD80 but not sCD86 concentrations were significantly higher than those of control subjects (all p < 0.05). Plasma sCD80 and sCD86 but not sCTLA-4 and sCD28 concentrations correlated significantly with IgE(log) of all subjects (p < 0.05). There were also significant positive correlations between sCTLA-4 and sCD28 (p = 0.0007), and between sCD80 and sCD86 in all asthmatic patients (p = 0.001).

CONCLUSIONS

Plasma sCTLA-4, sCD28 and sCD80 concentrations are elevated in allergic asthma. The increased expression of these soluble proteins may reflect the dysregulation of T cell activation, contributing to the immunopathogenesis of allergic asthma.

T cell subsets and mortality in older community-dwelling women

The relationship between specific T cell subset alterations and mortality has not been well characterized in older adults. The specific aim was to determine whether specific T cell subsets are associated with an increased risk of death. We conducted a case-control study of T cell subsets (CD4+ and CD8+ T cells, and subsets of these cells defined by expression or non-expression of CD28, CD45RA, and CD45RO) nested within two complementary prospective cohorts of women aged 65 and over living in the community, the Women's Health and Aging Studies (WHAS). Cases consisted of 61 women who died during 5 years of follow-up, and controls consisted of 61 women matched by age, frailty, and morbidities who survived during 7 years of follow-up. There were no significant differences between cases and controls in any of the T cell subsets studied. When analyses were stratified by frailty status, these data suggest that CD8+CD28- lymphocyte counts were significantly higher among women who were frail compared with pre-frail and non-frail women.

[Distribution of CD8+CD28- T cells and CD3+CD56+ NKT cells in peripheral blood of patients with B-cell non-Hodgkin's lymphoma]

BACKGROUND & OBJECTIVE

Patients with B-cell non-Hodgkin's lymphoma (B-NHL) usually have a poor immune response. CD8(+)CD28(-) T cells (Ts) and CD3(+)CD56(+) NKT cells (NKT) are new types of immune suppressor cells. This study was to analyze proportions and changes of them in peripheral blood of patients with B-NHL, explore their effects on immunosuppression of B-NHL, and the influnce factors, to provide reference for intervening in immune function of B-NHL patients.

METHODS

Peripheral blood samples were got from 79 naive patients with B-NHL before treatment, and 25 healthy people, samples of 18 patients who got complete remission (CR) after 4-6 cycles of chemotherapy were collected either before chemotherapy or after CR. Proportions of Ts and NKT were analyzed by flow cytometry (FCM).

RESULTS

Compared with control group, proportions of Ts, and NKT in peripheral blood of B-NHL patients before chemotherapy were (18.19+/-5.03)%, and (6.08+/-3.29)%, significantly higher than those of healthy people [(11.20+/-3.49)%, P< 0.01; (3.52+/-1.56)%, P< 0.01]. There were no significant differences of proportions of Ts among patients with B-NHL of different clinical stages (P >0.05), and different malignant grade (P >0.05), and between before treatment and after CR (P=0.55). No significant difference of proportions of NKT was found among patients with B-NHL of different clinical stages (P >0.05), and different malignant grade (P >0.05), and between before treatment and after CR (P=0.39).

CONCLUSION

Populations of Ts and NKT commonly increased in peripheral blood of patients with B-NHL, they may play roles in immunosuppression of B-NHL.

The expansion of CD4+CD28- T cells in patients with chronic kidney graft rejection

CD4+CD28- T cells are oligoclonal lymphocytes rarely found in healthy subjects, but are present in high frequencies in patients with inflammatory diseases. Contrary to paradigm, they are functionally active and produce interferon gamma and cytolytic proteins, are cytotoxic in vessels and may contribute to tissue damage. The size of the peripheral blood CD4+CD28- T cell compartments was determined in 20 healthy individuals, 20 patients after renal transplantation with stable graft function, and 20 with chronic graft rejection by two-color FACS analysis. In patients with stable graft function, the median frequency of CD4+CD28- T cells was 3.1% and was significantly higher in comparison to the control group (1.4%) (P <.01). The highest subset CD4+CD28- cells was detected in patients with chronic graft rejection (10.65%). The amount of CD4+CD28- cells was significantly higher in this group in comparison to patients with stable graft function (P <.01). The evaluated number of CD4+CD28- cells in patients after renal transplantation, especially in graft recipients with chronic graft rejection, suggests a role of these cells in chronic graft destruction.

The effects of calpain inhibition on IkB alpha degradation after activation of PBMCs: identification of the calpain cleavage sites

Human peripheral blood mononuclear cells (PBMCs) were activated using anti-CD3/CD28 (HIT3A/CD28.2) resulting in degradation of IkB alpha, an inhibitor of NFkB, relative to unactivated cells. Degradation of IkB alpha began by 30 min and proceeded for at least 5 h. Calpeptin, a calpain inhibitor, inhibited IkB alpha degradation in a time- and dose-dependent manner. Furthermore, calpain inhibition increased IkB alpha levels compared to nonactivated controls. Recombinant IkB alpha was incubated with purified porcine m-calpain in the presence of 0.1% Triton X-100, and the degradation products were monitored by SDS-PAGE and sequenced. Most of the degradation products were peptides derived from calpain, but one was derived from IkB alpha cleaved between amino acids 50 and 51 (glutamine and glutamic acid). The liberated fragment included the entire signal response domain (SRD), a region containing key serine and threonine residues necessary for phosphorylation by the IKKinase complex and sites required for ubiquitination. The results suggest that calpain plays an important role in IkB alpha degradation, a crucial event in T cell activation.

Detection of circulating soluble CD28 in patients with systemic lupus erythematosus, primary Sjögren's syndrome and systemic sclerosis

The aim of this study was to evaluate the presence and the role of the serum soluble costimulatory molecule CD28 in patients with systemic lupus erythematosus (SLE), primary Sjögren's syndrome (SS), and systemic sclerosis (SSc). Soluble CD28 concentration was determined by ELISA in 45 patients with SLE, 45 patients with primary SS, 30 patients with SSc, and 45 healthy subjects. We also evaluated CD28 mRNA expression by semiquantitative RT-PCR, and the biological activity of recombinant soluble CD28 on T lymphocyte activity. Concentrations of soluble CD28 were significantly higher in patients with SLE, primary SS and SSc than in healthy subjects. Soluble CD28 concentrations were higher in patients with systemic primary SS than in patients with glandular-limited primary SS. PCR analysis suggested that soluble CD28 resulted from the shedding of the membrane form. In vitro assay revealed that soluble CD28 inhibits the anti-CD3 mAb induced T cell proliferation. Soluble CD28, which modulates the proliferation of T lymphocytes, could be associated with disease severity in patients with autoimmune disease, especially primary SS. These results suggest that soluble CD28 could play an important role in the regulation of autoimmune diseases.

CD4+CD28- T lymphocytes contribute to early atherosclerotic damage in rheumatoid arthritis patients

BACKGROUND

Peripheral blood expansion of an unusual CD4+ T-cell subset lacking surface CD28 has been suggested to predispose rheumatoid arthritis (RA) patients to develop more aggressive disease. However, the potential association between CD4+CD28null T cells and early atherosclerotic changes in RA has never been investigated.

METHODS AND RESULTS

The number of circulating CD4+CD28null cells was evaluated in 87 RA and 33 control subjects who also underwent evaluation of carotid artery intima-media thickness (IMT) and endothelial function via flow-mediated vasodilation (FMV). Patients had higher IMT and lower FMV compared with control subjects. The frequency of CD4+CD28null cells was significantly higher in patients than in control subjects. Twenty patients with persistent expansion of circulating CD4+CD28null cells had more marked increase of carotid artery IMT and stronger decrease of brachial artery FMV. Blockade of tumor necrosis factor-alpha led to a partial reappearance of the CD28 molecule on the CD4+ cell surface.

CONCLUSIONS

Circulating CD4+CD28(null) lymphocytes are increased in RA. Patients with persistent CD4+CD28null cell expansion show preclinical atherosclerotic changes, including arterial endothelial dysfunction and carotid artery wall thickening, more significantly than patients without expansion. These findings suggest a contribution of this cell subset in atheroma development in RA. Moreover, the demonstration that tumor necrosis factor-alpha blockade is able to reverse, at least in part, the CD28 deficiency on the CD4+ cell surface may be of interest for possible innovative therapeutic strategies in cardiovascular diseases.